4-Way 2-Position Directional Valve (IL)

A four-line two-position distributor in an isothermal liquid network.

4 way 2 position directional valve il

Description

Block 4-Way 2-Position Directional Valve (IL) is a four-line spool valve, usually located between the hydraulic cylinder, pump and reservoir in an isothermal liquid network. The operation of the distributor is controlled by a single spool valve, which moves according to the signal on the S port. The distributor has two positions, hereinafter referred to as positive and negative. The basic configuration of the distributor can be set by specifying the channels that open when the spool moves in positive and negative directions in the parameters Positive spool position open connections and Negative spool position open connections respectively.

It is possible to set the flow characteristic of the distributor channels in the Orifice parameterization in the form of a linear dependence or a tabular function provided by the user, which can be applied to one or all channels of the distributor.

An example of distributor configuration is shown in the figure.

4 way 3 position directional valve il 1 en

In the configuration shown below, the spreader is connected to a tank, hydraulic actuator and pump, and the Negative spool position open connections parameters are set to P-A, B-T. When the signal at port S moves the spool to a negative position (left of neutral position), the channels between ports P and A and between ports B and T are open. The channels between ports P and B and ports A and T are closed.

4 way 3 position directional valve il 3

In the configuration below, the Positive spool position open connections parameters are set to `P-B, A-T'. When the signal at port S moves the spool to the positive position (to the right of the neutral position), the channels between ports P and B and between ports A and T are open, and the channels between ports P and A and between ports B and T are closed.

4 way 3 position directional valve il 4

Spool valve movement and distributor configuration

Spool travel is the amount of spool movement between a fully open and fully closed channel. The Orifice parameterization and Area characteristics parameters can be used to set the channel characteristics as shown in the table.

Orifice Parameterization Identical for All Flow Paths Different for Each Flow Path.

Orifice Parameterization	`Identical for All Flow Paths`	`Different for Each Flow Path`.
`Linear - Area vs. spool travelling`.	Spool travel is equal to the value of the parameter Spool travel between closed and open orifice.	Spool travel equals the value of the Spool travel between closed and open orifice parameters for each channel.
`Tabulated data - Area vs. spool travel`	Spool travel is equal to the difference between the first and the last element of the Spool travel vector parameters.	Spool travel equals the difference between the first and last element of the Spool travel vector parameters for each channel.
`Tabulated data - Volumetric flow rate vs. spool travel and pressure drop`	Spool travel equals the difference between the first and the last element of the Spool travel vector, ds parameters.	Spool travel equals the difference between the first and last element of the Spool travel vector, ds parameters for each channel.

Linear - Area vs. spool travelling.

Spool travel is equal to the value of the parameter Spool travel between closed and open orifice.

Spool travel equals the value of the Spool travel between closed and open orifice parameters for each channel.

Tabulated data - Area vs. spool travel

Spool travel is equal to the difference between the first and the last element of the Spool travel vector parameters.

Spool travel equals the difference between the first and last element of the Spool travel vector parameters for each channel.

Tabulated data - Volumetric flow rate vs. spool travel and pressure drop

Spool travel equals the difference between the first and the last element of the Spool travel vector, ds parameters.

Spool travel equals the difference between the first and last element of the Spool travel vector, ds parameters for each channel.

The table below shows how to determine the relative spool position for a channel depending on the values selected for the parameters Positive spool position open connection and Negative spool position open connection.

Spool position at open channel	Relative spool position for the channel
Channel always closed: channel not selected in parameters Positive spool position open connection or Negative spool position open connection.	Not used
Channel always open: channel is selected in the parameters Positive spool position open connection and Negative spool position open connection.	Not used
Negative position: the channel is selected only in the parameters Negative spool position open connection	− S + spool stroke
Positive position: channel is selected only in the Positive spool position open connection parameters.	S − + spool stroke

Spool position at open channel

Relative spool position for the channel

Channel always closed: channel not selected in parameters Positive spool position open connection or Negative spool position open connection.

Not used

Channel always open: channel is selected in the parameters Positive spool position open connection and Negative spool position open connection.

Not used

Negative position: the channel is selected only in the parameters Negative spool position open connection

− S + spool stroke

Positive position: channel is selected only in the Positive spool position open connection parameters.

S − + spool stroke

Where is the spool position at maximum orifice area (value of the Spool position at maximum orifice area parameters) set for each channel. The flow area is equal to the leakage area when the value of is negative, and is equal to the maximum when the channel is fully open. When the channel is fully open, the relative position equates to the spool stroke, so if exceeds the spool stroke, it does not further increase the channel cross-sectional area.

The table below shows the possible unit configurations 4-Way 2-Position Directional Valve (IL).

Configuration Parameter values

Configuration	Parameter values
All four channels are closed in the intermediate position (neutral position).	Positive spool position open connections: `P-A, B-T Negative spool position open connections: `P-B, A-T Spool position at maximum P-A orifice area* > P-A spool stroke Spool position at maximum P-B orifice area < −P-B spool stroke Spool position at maximum A-T orifice area < −A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
All four channels are open in the intermediate position (neutral position).	Positive spool position open connections: `P-A, B-T Negative spool position open connections: `P-B, A-T Spool position at maximum P-A orifice area* < P-A ход золотника Spool position at maximum P-B orifice area > − P-B spool stroke Spool position at maximum A-T orifice area > −A-T spool stroke Spool position at maximum B-T orifice area < B-T spool stroke
A-T and B-T are closed in the intermediate position (neutral position).	Positive spool position open connections: `P-A, B-T Negative spool position open connections: `P-B, A-T Spool position at maximum P-A orifice area* < P-A ход золотника Spool position at maximum P-B orifice area > − P-B spool stroke Spool position at maximum A-T orifice area < −A-T spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
P-A and P-B are closed in the intermediate position (neutral position).	Positive spool position open connections: `P-A` Negative spool position open connections: `P-B Spool position at maximum P-A orifice area > P-A spool stroke Spool position at maximum P-B orifice area < −P-B spool stroke
P-B and B-T are closed in the intermediate position (neutral position).	Positive spool position open connections: `P-B, A-T Negative spool position open connections: `P-A, B-T Spool position at maximum P-A orifice area* < P-A ход золотника Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area > A-T spool stroke Spool position at maximum B-T orifice area < −B-T spool stroke
P-A and A-T are closed in the intermediate position (neutral position).	Positive spool position open connections: `P-B, A-T Negative spool position open connections: `P-A, B-T Spool position at maximum P-A orifice area < −P-A spool stroke Spool position at maximum P-B orifice area < P-B ход золотника Spool position at maximum A-T orifice area > A-T spool stroke Spool position at maximum B-T orifice area > −B-T spool stroke
P-A, P-B and B-T are open in the intermediate position (neutral position).	Positive spool position open connections: `P-A, P-B Negative spool position open connections: `P-A, B-T Spool position at maximum P-A orifice area < P-A spool stroke Spool position at maximum P-B orifice area < P-B ход золотника Spool position at maximum A-T orifice area = любое значение Spool position at maximum B-T orifice area > − B-T spool stroke
P-A, A-T and B-T are open in the intermediate position (neutral position).	Positive spool position open connections: `P-B, A-T Negative spool position open connections: `P-A, P-B Spool position at maximum P-A orifice area > −P-A spool stroke Spool position at maximum A-T orifice area < A-T spool stroke Spool position at maximum B-T orifice area = any value
P-A and P-B are closed in the intermediate position (neutral position). A-T is always closed.	Positive spool position open connections: `P-A, P-B Negative spool position open connections: `P-A, B-T Spool position at maximum P-B orifice area* > P-B spool stroke Spool position at maximum B-T orifice area < −B-T spool stroke
All channels are closed in the intermediate position (neutral position).	Positive spool position open connections: `P-B, A-T Negative spool position open connections: `P-A, P-B Spool position at maximum P-A orifice area* < −P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area > A-T spool stroke
In the intermediate position (neutral position) A-T is open, P-A is closed.	Positive spool position open connections: `P-A, P-B Negative spool position open connections: `P-A, B-T Spool position at maximum P-A orifice area* > P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area = any value Spool position at maximum B-T orifice area > −B-T spool stroke
In the intermediate position (neutral position) B-T is open, P-B is closed.	Positive spool position open connections: `P-B, A-T Negative spool position open connections: `P-A, P-B Spool position at maximum P-A orifice area* < −P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area < A-T spool stroke Spool position at maximum B-T orifice area = any value
P-A closed in intermediate position (neutral position).	Positive spool position open connections: `P-A, B-T Negative spool position open connections: `P-A, P-B Spool position at maximum P-A orifice area* > P-A spool stroke Spool position at maximum P-B orifice area < −P-B spool stroke Spool position at maximum B-T orifice area > B-T spool stroke
P-B is closed in the intermediate position (neutral position).	Positive spool position open connections: `P-A, P-B Negative spool position open connections: `P-B, A-T Spool position at maximum P-A orifice area* > P-A spool stroke Spool position at maximum P-B orifice area > P-B spool stroke Spool position at maximum A-T orifice area > −A-T spool stroke

All four channels are closed in the intermediate position (neutral position).

4 way 2 position directional valve il 1

Positive spool position open connections: `P-A, B-T

*Negative spool position open connections: `P-B, A-T

Spool position at maximum P-A orifice area > P-A spool stroke

Spool position at maximum P-B orifice area < −P-B spool stroke

Spool position at maximum A-T orifice area < −A-T spool stroke

Spool position at maximum B-T orifice area > B-T spool stroke

All four channels are open in the intermediate position (neutral position).

4 way 2 position directional valve il 1

Positive spool position open connections: `P-A, B-T

*Negative spool position open connections: `P-B, A-T

Spool position at maximum P-A orifice area < P-A ход золотника

Spool position at maximum P-B orifice area > − P-B spool stroke

Spool position at maximum A-T orifice area > −A-T spool stroke

Spool position at maximum B-T orifice area < B-T spool stroke

A-T and B-T are closed in the intermediate position (neutral position).

4 way 2 position directional valve il 1

Positive spool position open connections: `P-A, B-T

*Negative spool position open connections: `P-B, A-T

Spool position at maximum P-A orifice area < P-A ход золотника

Spool position at maximum P-B orifice area > − P-B spool stroke

Spool position at maximum A-T orifice area < −A-T spool stroke

Spool position at maximum B-T orifice area > B-T spool stroke

P-A and P-B are closed in the intermediate position (neutral position).

4 way 2 position directional valve il 2

Positive spool position open connections: P-A

Negative spool position open connections: `P-B

Spool position at maximum P-A orifice area > P-A spool stroke

Spool position at maximum P-B orifice area < −P-B spool stroke

P-B and B-T are closed in the intermediate position (neutral position).

4 way 2 position directional valve il 3

Positive spool position open connections: `P-B, A-T

*Negative spool position open connections: `P-A, B-T

Spool position at maximum P-A orifice area < P-A ход золотника

Spool position at maximum P-B orifice area > P-B spool stroke

Spool position at maximum A-T orifice area > A-T spool stroke

Spool position at maximum B-T orifice area < −B-T spool stroke

P-A and A-T are closed in the intermediate position (neutral position).

4 way 2 position directional valve il 3

Positive spool position open connections: `P-B, A-T

Negative spool position open connections: `P-A, B-T

Spool position at maximum P-A orifice area < −P-A spool stroke

Spool position at maximum P-B orifice area < P-B ход золотника

Spool position at maximum A-T orifice area > A-T spool stroke

Spool position at maximum B-T orifice area > −B-T spool stroke

P-A, P-B and B-T are open in the intermediate position (neutral position).

4 way 2 position directional valve il 4

Positive spool position open connections: `P-A, P-B

Negative spool position open connections: `P-A, B-T

Spool position at maximum P-A orifice area < P-A spool stroke

Spool position at maximum P-B orifice area < P-B ход золотника

Spool position at maximum A-T orifice area = любое значение

Spool position at maximum B-T orifice area > − B-T spool stroke

P-A, A-T and B-T are open in the intermediate position (neutral position).

4 way 2 position directional valve il 5

Positive spool position open connections: `P-B, A-T

Negative spool position open connections: `P-A, P-B

Spool position at maximum P-A orifice area > −P-A spool stroke

Spool position at maximum A-T orifice area < A-T spool stroke

Spool position at maximum B-T orifice area = any value

P-A and P-B are closed in the intermediate position (neutral position). A-T is always closed.

4 way 2 position directional valve il 4

Positive spool position open connections: `P-A, P-B

*Negative spool position open connections: `P-A, B-T

Spool position at maximum P-B orifice area > P-B spool stroke

Spool position at maximum B-T orifice area < −B-T spool stroke

All channels are closed in the intermediate position (neutral position).

4 way 2 position directional valve il 5

Positive spool position open connections: `P-B, A-T

*Negative spool position open connections: `P-A, P-B

Spool position at maximum P-A orifice area < −P-A spool stroke

Spool position at maximum P-B orifice area > P-B spool stroke

Spool position at maximum A-T orifice area > A-T spool stroke

In the intermediate position (neutral position) A-T is open, P-A is closed.

4 way 2 position directional valve il 6

Positive spool position open connections: `P-A, P-B

*Negative spool position open connections: `P-A, B-T

Spool position at maximum P-A orifice area > P-A spool stroke

Spool position at maximum P-B orifice area > P-B spool stroke

Spool position at maximum A-T orifice area = any value

Spool position at maximum B-T orifice area > −B-T spool stroke

In the intermediate position (neutral position) B-T is open, P-B is closed.

4 way 2 position directional valve il 5

Positive spool position open connections: `P-B, A-T

*Negative spool position open connections: `P-A, P-B

Spool position at maximum P-A orifice area < −P-A spool stroke

Spool position at maximum P-B orifice area > P-B spool stroke

Spool position at maximum A-T orifice area < A-T spool stroke

Spool position at maximum B-T orifice area = any value

P-A closed in intermediate position (neutral position).

4 way 2 position directional valve il 7

Positive spool position open connections: `P-A, B-T

*Negative spool position open connections: `P-A, P-B

Spool position at maximum P-A orifice area > P-A spool stroke

Spool position at maximum P-B orifice area < −P-B spool stroke

Spool position at maximum B-T orifice area > B-T spool stroke

P-B is closed in the intermediate position (neutral position).

4 way 2 position directional valve il 8

Positive spool position open connections: `P-A, P-B

*Negative spool position open connections: `P-B, A-T

Spool position at maximum P-A orifice area > P-A spool stroke

Spool position at maximum P-B orifice area > P-B spool stroke

Spool position at maximum A-T orifice area > −A-T spool stroke

Parametrization of the distributor channels

The Orifice parameterization parameter sets the method of calculating the cross-sectional area. Calculation is performed either by channel parameters or by tabular data sets, which are set in parameters of Model Parameterization section. The block uses the same data for all channels if the Area characteristics parameter is set to Identical for all flow paths, and if Different for all flow paths is set, then individual values are set for each channel.

Parameterization of distributor channels Orifice parameterization can be linear and tabular.

Linear parameterization

If Linear - Area vs. spool travel is selected for the Orifice parameterization, the flow area of the channel depends linearly on the spool travel and the value supplied to the port S:

where

- is the maximum cross-sectional area of the channel (value of the Maximum orifice area parameters);
- leakage area (value of parameters Leakage area);
- spool travel between closed and open states of the channel (value of parameter Spool travel between closed and open orifice);
- spool relative position, from 0 to .

is equal to , when the value of is negative, and is equal to , when the channel is fully open. When the channel is fully open, the relative position is equal to the spool travel, so the value , which exceeds the spool travel, does not increase the flow area.

Note the linear increase from to in the figure:

Static

When the channel is in the nearly open or nearly closed position in the linear parameterization, the numerical stability of the simulation can be maintained by adjusting the smoothing factor - the value of the Smoothing factor parameter. If the Smoothing factor parameter is not zero, a smooth change in the cross-sectional area between and is ensured.

Table parameterization

If Tabulated data - Area vs. spool travel is selected for the Orifice parameterization, the vectors of the relationship between the bore area and the relative position of the spool must be defined. Interpolation is used to determine the orifice area between the defined data points. and are the first and last elements of the Opening area vector respectively.

Static

If Tabulated data - Volumetric flow rate vs. spool travel and pressure drop is selected for the Orifice parameterization, the vectors for the relative spool position and pressure drop must be set. The volumetric flow rate is calculated from the relationship between pressure drop and relative spool position. Interpolation is used to determine the flow rate between given data points. The mass flow rate is the product of the volumetric flow rate and density.

Static

Ports

Conserving

# P — isothermal liquid port
isothermal liquid

Details

Working fluid supply.

Program usage name

port_p

# T — isothermal liquid port
isothermal liquid

Details

Working fluid outlet.

Program usage name

port_t

# A — isothermal liquid port
isothermal liquid

Details

Working line.

Program usage name

port_a

# B — isothermal liquid port
isothermal liquid

Details

Working line.

Program usage name

port_b

Input

# S — distributor spool position
scalar

Details

Position of the distributor spool valve in m. Channels set open in the positive position of the spool valve are opened at positive travel. Channels set open in the negative position of the spool valve open at negative travel.

Data types	`Float64`.
Complex numbers support	No

Parameters

Valve Configuration

Details

Channels open in positive position. This parameters sets the distributor configuration and determines the relative position of the spool valve according to the signal received at port S.

Values	`All closed` \| `P-A and B-T` \| `P-A and P-B` \| `P-B and A-T` \| `A-T only` \| `B-T only` \| `P-A only` \| `P-B only` \| `P-A, P-B, A-T, and B-T`
Default value	`P-A and B-T`
Program usage name	`positive_position_open_orifices`
Evaluatable	No

Details

Channels open in negative position. This parameters sets the distributor configuration and determines the relative position of the spool valve according to the signal received at port S.

Values	`All closed` \| `P-A and B-T` \| `P-A and P-B` \| `P-B and A-T` \| `A-T only` \| `B-T only` \| `P-A only` \| `P-B only` \| `P-A, P-B, A-T, and B-T`
Default value	`P-B and A-T`
Program usage name	`negative_position_open_orifices`
Evaluatable	No

Model Parameterization

# Area characteristics — channel characterisation method
Identical for all flow paths | Different for each flow path

Details

Sets identical or individual flow characteristics for the channel cross-section:

Identical for all flow paths - identical characteristics for all flow paths of the distributor.
Different for each flow path - individual characteristics are set for each channel.

In both cases ports A, B, P and T have identical cross-sectional areas, flow coefficients and Reynolds numbers if the Orifice parameterization parameters are set to Linear - Area vs. spool travel or Tabulated data - Area vs. spool travel.

Values	`Identical for all flow paths` \| `Different for each flow path`
Default value	`Identical for all flow paths`
Program usage name	`area_characteristics`
Evaluatable	No

# Orifice parameterization — channel area calculation method
Linear - Area vs. spool travel | Tabulated data - Area vs. spool travel | Tabulated data - Volumetric flow rate vs. spool travel and pressure drop

Details

A method for calculating the area of a channel cross-sectional area in modelling.

At tabular parameterization it is possible to specify a non-linear profile of the flow characteristic of the channels in the form of dependence of the flow area on the spool position or dependence of the volume flow rate on the pressure drop and spool position.

Values	`Linear - Area vs. spool travel` \| `Tabulated data - Area vs. spool travel` \| `Tabulated data - Volumetric flow rate vs. spool travel and pressure drop`
Default value	`Linear - Area vs. spool travel`
Program usage name	`orifice_parameterization`
Evaluatable	No

# Spool travel between closed and open orifice — maximum spool stroke
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool stroke between closed and open channel states.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Linear - Area vs. spool travel'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`max_spool_travel`
Evaluatable	Yes

# Maximum orifice area — maximum cross-sectional area of the channel
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Maximum cross-sectional area of the channel.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Linear - Area vs. spool travel'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`max_area`
Evaluatable	Yes

# Spool travel vector — vector of values of the spool relative position
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of values of the spool relative position. The dimensionality of the vector corresponds to the Orifice area vector. The values are listed in ascending order and the first element must be equal to 0. Linear interpolation is used between the data points in the table.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Tabulated data - Area vs. spool travel'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector`
Evaluatable	Yes

# Orifice area vector — vector of values of the channel cross-sectional area
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Vector of channel cross-sectional area values for tabular parameterization. The dimension of the vector corresponds to the Spool travel vector. The values are listed in ascending order. The first element is the leakage area, the last element is the maximum channel cross-sectional area. Linear interpolation is used between data points.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Tabulated data - Area vs. spool travel'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1e-10, 1e-5, 4e-5, 6e-5, 1e-4] m^2`
Program usage name	`valve_area_vector`
Evaluatable	Yes

# Spool travel vector, ds — vector of values of the spool relative position
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool position values for the table parameterization of the volumetric flow rate table. The dimension of the spool position vector corresponds to the differential pressure vector Pressure drop vector, dp and the volumetric flow rate table Volumetric flow rate table, q(ds,dp). The values are listed in ascending order and the first element must be 0. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Tabulated data - Volumetric flow rate vs. spool travel and pressure drop'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_2D`
Evaluatable	Yes

# Pressure drop vector, dp — vector of differential pressure values
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for tabular parameterization by volumetric flow rate. The dimension of the differential pressure vector corresponds to the spool position vector Spool travel vector, ds and the volumetric flow rate table Volumetric flow rate table, q(ds,dp). The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D`
Evaluatable	Yes

# Volumetric flow rate table, q(ds,dp) — table of volumetric flow rates
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Matrix to of volume flow rates corresponding to differential pressure and spool position values. to - dimensions of the corresponding vectors:

- number of elements in the spool position vector Spool travel vector, ds.
- number of elements in the pressure drop vector Pressure drop vector, dp.

Dependencies

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-1e-8 2.2e-8 2.8e-8 3.4e-8; -9e-6 1.5e-4 2e-4 2.4e-4; -3.6e-4 6.3e-4 8.1e-4 9.6e-4; -5.4e-4 9.4e-4 1.2e-3 1.4e-3; -9.1e-4 1.6e-3 2.0e-3 2.4e-3] m^3/s`
Program usage name	`Vdot_matrix_2D`
Evaluatable	Yes

# Constant orifice area — cross-sectional area for permanently open channels
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of channels defined open in both positions.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Identical for all flow paths.
Orifice parameterization to Linear - area vs. spool travel or Tabulated data - Area vs. spool travel.
Positive spool position open connections and Negative spool position open connections - at least one channel is set in both positions.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`area_fixed`
Evaluatable	Yes

# Constant orifice pressure drop vector — vector of differential pressure values for permanently open channels
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for channels defined open in both positions. The dimension of the differential pressure vector corresponds to the Constant orifice volumetric flow rate vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Identical for all flow paths.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections - at least one channel is set in both positions.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_fixed`
Evaluatable	Yes

# Constant orifice volumetric flow rate vector — vector of volume flow rates for permanently open channels
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Vector of volume flow values for channels set open in both positions. The dimension of the pressure drop vector corresponds to the Constant orifice pressure drop vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Identical for all flow paths.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections - at least one channel is set in both positions.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-9e-4, 1.6e-3, 2.0e-3, 2.4e-3] m^3/s`
Program usage name	`Vdot_vector_fixed`
Evaluatable	Yes

# Leakage area — leakage area through the channel in fully closed position
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The sum of all clearances when the channel is completely closed. Any area less than this value equates to the specified leakage area. This parameter contributes to the stability of the numerical solution by maintaining flow continuity.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Linear - area vs. spool travel'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-10 m^2`
Program usage name	`leakage_area`
Evaluatable	Yes

# Cross-sectional area at ports P, T, A and B — area at the inlet or outlet of the distributor
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area at ports A, B, P, and T. This area is used in calculating the mass flow rate through the distributor.

Dependencies

To use this parameter, set the Area characteristics parameter to `Identical for all flow paths' and the Orifice parameterization parameter to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`Inf m^2`
Program usage name	`port_area`
Evaluatable	Yes

# Discharge coefficient — flow coefficient

Details

The correction factor is the ratio of the actual mass flow rate to the theoretical mass flow rate through the distributor.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

Default value	`0.64`
Program usage name	`C_d`
Evaluatable	Yes

# Critical Reynolds number — upper limit of Reynolds number for laminar flow

Details

Upper Reynolds number limit for laminar flow through a channel.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

Default value	`150.0`
Program usage name	`Re_critical`
Evaluatable	Yes

# Smoothing factor — numerical smoothing factor

Details

A continuous smoothing factor that ensures smooth opening by correcting the channel characteristic in the nearly open and nearly closed positions.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Linear - area vs. spool travel.

Default value	`0.01`
Program usage name	`smoothing_factor`
Evaluatable	Yes

# Pressure recovery — whether to take into account the increase in pressure when expanding the area

Details

Whether to take into account the pressure increase when the fluid flows from a region with a smaller cross-sectional area to a region with a larger cross-sectional area.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

Default value	`false (switched off)`
Program usage name	`pressure_recovery`
Evaluatable	No

P-A Orifice

# Spool position at maximum P-A orifice area — spool position at maximum channel area between ports P and A
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool position corresponding to a fully open channel between ports P and A.

Dependencies

To use this parameter, set the Positive spool position open connections or Negative spool position open connections parameters to one of the following values:

`P-A and B-T
`P-A and P-B
`P-A only
P-A, P-B, A-T, and B-T.

This parameter is enabled only if the P-A channel is not set simultaneously in both parameters Positive spool position open connections and Negative spool position open connections.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`5e-3 m`
Program usage name	`spool_offset_pa`
Evaluatable	Yes

# P-A spool travel between closed and open orifice — maximum spool stroke between ports P and A
m | cm | ft | in | km | mi | mm | um | yd

Details

Maximum spool stroke between ports P and A.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`max_spool_travel_pa`
Evaluatable	Yes

# P-A maximum orifice area — maximum area between ports P and A
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The channel cross-sectional area between ports P and A in the fully open position.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`max_area_pa`
Evaluatable	Yes

# P-A orifice spool travel vector — vector of spool relative positions
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions. The dimensionality of the vector corresponds to the P-A orifice area vector. The values are listed in ascending order and the first element must be 0. Linear interpolation is used between the data points in the table.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_pa`
Evaluatable	Yes

# P-A orifice area vector — vector of values of the channel cross-sectional area
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Vector of channel cross-sectional area values for the tabular parameterization of the valve area. The dimension of the vector corresponds to the P-A orifice spool travel vector. The values are listed in ascending order and must be greater than 0.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1e-10, 1e-5, 4e-5, 6e-5, 1e-4] m^2`
Program usage name	`valve_area_vector_pa`
Evaluatable	Yes

# P-A orifice spool travel vector, ds — vector of values of the spool relative position
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions for tabular parameterization by volume flow. The dimension of the spool position vector corresponds to the pressure drop vector P-A orifice pressure drop vector,dp and the volumetric flow rate table P-A orifice volumetric flow rate table, q(s,dp). The values are listed in ascending order and the first element must be 0. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_2D_pa`
Evaluatable	Yes

# P-A orifice pressure drop vector, dp — vector of differential pressure values
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for tabular parameterization by volume flow. The differential pressure vector corresponds to the position vector of the spool valve. P-A orifice spool travel vector, ds and volumetric flow rate table, q(ds,ds). P-A orifice volumetric flow rate table, q(ds,dp). The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D_pa`
Evaluatable	Yes

# P-A orifice volumetric flow rate table, q(ds,dp) — table of volumetric flow rates
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Matrix to of volume flow rates corresponding to differential pressure and spool position values. to - dimensions of the corresponding vectors:

- number of elements in the spool position vector P-A orifice spool travel vector, ds.
- number of elements in the pressure drop vector P-A orifice pressure drop vector, dp.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- `P-A, P-B, A-T, and B-T'.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-1e-8 2.2e-8 2.8e-8 3.4e-8; -9e-6 1.5e-4 2e-4 2.4e-4; -3.6e-4 6.3e-4 8.1e-4 9.6e-4; -5.4e-4 9.4e-4 1.2e-3 1.4e-3; -9.1e-4 1.6e-3 2.0e-3 2.4e-3] m^3/s`
Program usage name	`Vdot_matrix_2D_pa`
Evaluatable	Yes

# P-A constant orifice area — cross-sectional area for a permanently open channel
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of a channel defined as open in both positions.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - area vs. spool travel or Tabulated data - Area vs. spool travel.
Positive spool position open connections and Negative spool position open connections one of the channels:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the P-A channel is set in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`area_fixed_pa`
Evaluatable	Yes

# P-A constant orifice pressure drop vector — vector of differential pressure values of a permanently open channel
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for a channel defined open in both positions. The dimension of the differential pressure vector corresponds to the P-A constant orifice volumetric flow rate vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections one of the channels:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the P-A channel is set in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_fixed_pa`
Evaluatable	Yes

# P-A constant volumetric flow rate vector — vector of values of volume flow rate of a permanently open channel
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Vector of volume flow values for a channel defined open in both positions. The dimension of the pressure drop vector corresponds to the P-A constant orifice pressure drop vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections one of the channels:
- `P-A and B-T
- `P-A and P-B
- `P-A only
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the P-A channel is set in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-9e-4, 1.6e-3, 2.0e-3, 2.4e-3] m^3/s`
Program usage name	`Vdot_vector_fixed_pa`
Evaluatable	Yes

P-B Orifice

# Spool position at maximum P-B orifice area — spool position at maximum channel area between ports P and B
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool position corresponding to a fully open channel between ports P and B.

Dependencies

To use this parameter, set the Positive spool position open connections or Negative spool position open connections parameters to one of the following values:

`P-B and A-T
`P-A and P-B
`P-B only
`P-A, P-B, A-T, and B-T'.

This parameter is enabled only if the P-B channel is not set simultaneously in both parameters Positive spool position open connections and Negative spool position open connections.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`-5e-3 m`
Program usage name	`spool_offset_pb`
Evaluatable	Yes

# P-B spool travel between closed and open orifice — maximum spool stroke between ports P and B
m | cm | ft | in | km | mi | mm | um | yd

Details

Maximum spool stroke between ports P and B.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`max_spool_travel_pb`
Evaluatable	Yes

# P-B maximum orifice area — maximum area between ports P and B
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area between ports P and B in the fully open position.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`max_area_pb`
Evaluatable	Yes

# P-B orifice spool travel vector — vector of spool relative positions
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions. The dimensionality of the vector corresponds to the P-B orifice area vector. The values are listed in ascending order and the first element must be 0. Linear interpolation is used between the data points in the table.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_pb`
Evaluatable	Yes

# P-B orifice area vector — vector of values of the channel cross-sectional area
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Vector of channel cross-sectional area values for the tabular parameterization of the valve area. The dimension of the vector corresponds to the P-B orifice spool travel vector. The values are listed in ascending order and must be greater than 0.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1e-10, 1e-5, 4e-5, 6e-5, 1e-4] m^2`
Program usage name	`valve_area_vector_pb`
Evaluatable	Yes

# P-B orifice spool travel vector, ds — vector of values of the spool relative position
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions for tabular parameterization by volume flow. The dimension of the spool position vector corresponds to the differential pressure vector P-B orifice pressure drop vector,dp and the volumetric flow rate table P-B orifice volumetric flow rate table, q(s,dp). The values are listed in ascending order and the first element must be 0. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_2D_pb`
Evaluatable	Yes

# P-B orifice pressure drop vector, dp — vector of differential pressure values
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for tabular parameterization by volume flow. The differential pressure vector corresponds to the position vector of the spool valve. P-B orifice spool travel vector, ds and volumetric flow rate table, q(ds,ds). P-B orifice volumetric flow rate table, q(ds,dp). The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D_pb`
Evaluatable	Yes

# P-B orifice volumetric flow rate table, q(ds,dp) — table of volumetric flow rates
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Matrix to of volume flow rates corresponding to differential pressure and spool position values. to - dimensions of the corresponding vectors:

- number of elements in the spool position vector P-B orifice spool travel vector, ds.
- number of elements in the pressure drop vector P-B orifice pressure drop vector, dp.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- `P-A, P-B, A-T, and B-T'.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-1e-8 2.2e-8 2.8e-8 3.4e-8; -9e-6 1.5e-4 2e-4 2.4e-4; -3.6e-4 6.3e-4 8.1e-4 9.6e-4; -5.4e-4 9.4e-4 1.2e-3 1.4e-3; -9.1e-4 1.6e-3 2.0e-3 2.4e-3] m^3/s`
Program usage name	`Vdot_matrix_2D_pb`
Evaluatable	Yes

# P-B constant orifice area — cross-sectional area of the permanently open channel
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of a channel defined as open in both positions.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - area vs. spool travel or Tabulated data - Area vs. spool travel.
Positive spool position open connections and Negative spool position open connections one of the channels:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the P-B channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`area_fixed_pb`
Evaluatable	Yes

# P-B constant orifice pressure drop vector — vector of differential pressure values for a permanently open channel
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for a channel defined open in both positions. The dimension of the differential pressure vector corresponds to the P-B constant orifice volumetric flow rate vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections one of the channels:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the P-B channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_fixed_pb`
Evaluatable	Yes

# P-B constant volumetric flow rate vector — vector of values of the volume constant open channel
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Vector of volumetric flow rate values for a channel defined open in both positions. The dimension of the pressure drop vector corresponds to the P-B constant orifice pressure drop vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections one of the channels:
- `P-B and A-T
- `P-A and P-B
- `P-B only
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the P-B channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-9e-4, 1.6e-3, 2.0e-3, 2.4e-3] m^3/s`
Program usage name	`Vdot_vector_fixed_pb`
Evaluatable	Yes

A-T Orifice

# Spool position at maximum A-T orifice area — spool position at maximum channel area between ports A and T
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool position corresponding to a fully open channel between ports A and T.

Dependencies

To use this parameter, set the Positive spool position open connections or Negative spool position open connections parameters to one of the following values:

A-T only.
`P-B and A-T
`P-A, P-B, A-T, and B-T'.

This parameter is enabled only if the A-T channel is not set simultaneously in both parameters Positive spool position open connections and Negative spool position open connections.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`-5e-3 m`
Program usage name	`spool_offset_at`
Evaluatable	Yes

# A-T spool travel between closed and open orifice — maximum spool stroke between ports A and T
m | cm | ft | in | km | mi | mm | um | yd

Details

Maximum spool stroke between ports A and T.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`max_spool_travel_at`
Evaluatable	Yes

# A-T maximum orifice area — maximum area between ports A and T
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area between ports A and T in the fully open position.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`max_area_at`
Evaluatable	Yes

# A-T orifice spool travel vector — vector of spool relative positions
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions. The dimensionality of the vector corresponds to the A-T orifice area vector. The values are listed in ascending order and the first element must be 0. Linear interpolation is used between the data points in the table.

Dependencies

To use this parameter, set the parameters to:

Area characteristics value Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_at`
Evaluatable	Yes

# A-T orifice area vector — vector of values of the channel cross-sectional area
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Vector of channel cross-sectional area values for the tabular parameterization of the valve area. The dimension of the vector corresponds to the A-T orifice spool travel vector. The values are listed in ascending order and must be greater than 0.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1e-10, 1e-5, 4e-5, 6e-5, 1e-4] m^2`
Program usage name	`valve_area_vector_at`
Evaluatable	Yes

# A-T orifice spool travel vector, ds — vector of values of the spool relative position
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions for tabular parameterization by volume flow. The dimension of the spool position vector corresponds to the differential pressure vector A-T orifice pressure drop vector,dp and the volumetric flow rate table A-T orifice volumetric flow rate table, q(s,dp). The values are listed in ascending order and the first element must be 0. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_2D_at`
Evaluatable	Yes

# A-T orifice pressure drop vector, dp — vector of differential pressure values
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for tabular parameterization by volume flow. The differential pressure vector corresponds to the position vector of the spool valve. A-T orifice spool travel vector, ds and the volumetric flow rate table A-T orifice volumetric flow rate table, q(ds,dp). The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D_at`
Evaluatable	Yes

# A-T orifice volumetric flow rate table, q(ds,dp) — table of volumetric flow rates
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Matrix to of volume flow rates corresponding to differential pressure and spool position values. to - dimensions of the corresponding vectors:

- number of elements in the spool position vector A-T orifice spool travel vector, ds.
- number of elements in the pressure drop vector A-T orifice pressure drop vector, dp.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- A-T only.
- `P-B and A-T
- `P-A, P-B, A-T, and B-T'.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-1e-8 2.2e-8 2.8e-8 3.4e-8; -9e-6 1.5e-4 2e-4 2.4e-4; -3.6e-4 6.3e-4 8.1e-4 9.6e-4; -5.4e-4 9.4e-4 1.2e-3 1.4e-3; -9.1e-4 1.6e-3 2.0e-3 2.4e-3] m^3/s`
Program usage name	`Vdot_matrix_2D_at`
Evaluatable	Yes

# A-T constant orifice area — cross-sectional area of the permanently open channel
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of a channel defined as open in both positions.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - area vs. spool travel or Tabulated data - Area vs. spool travel.
Positive spool position open connections and Negative spool position open connections one of the channels:
- A-T only.
- `P-B and A-T
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the A-T channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`area_fixed_at`
Evaluatable	Yes

# A-T constant orifice pressure drop vector — vector of differential pressure values for a permanently open channel
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for a channel defined open in both positions. The dimension of the differential pressure vector corresponds to the A-T constant orifice volumetric flow rate vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections one of the channels:
- A-T only.
- `P-B and A-T
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the A-T channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_fixed_at`
Evaluatable	Yes

# A-T constant volumetric flow rate vector — vector of values of the volume constant open channel
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Vector of volumetric flow rate values for a channel defined open in both positions. The dimension of the pressure drop vector corresponds to the A-T constant orifice pressure drop vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections and Negative spool position open connections one of the channels:
- A-T only.
- `P-B and A-T
- P-A, P-B, A-T, and B-T

This parameter is enabled only if the A-T channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-9e-4, 1.6e-3, 2.0e-3, 2.4e-3] m^3/s`
Program usage name	`Vdot_vector_fixed_at`
Evaluatable	Yes

B-T Orifice

# Spool position at maximum B-T orifice area — spool position at maximum channel area between ports B and T
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool position corresponding to a fully open channel between ports B and T.

Dependencies

To use this parameter, set the parameters Positive spool position open connections or Negative spool position open connections to `P-A and B-T'.

To use this parameter, set the Positive spool position open connections or Negative spool position open connections parameters to one of the following values:

B-T only.
`P-A and B-T
P-A, P-B, A-T, and B-T.

This parameter is enabled only if the B-T channel is not set simultaneously in both parameters Positive spool position open connections and Negative spool position open connections.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`5e-3 m`
Program usage name	`spool_offset_bt`
Evaluatable	Yes

# B-T spool travel between closed and open orifice — maximum spool stroke between ports B and T
m | cm | ft | in | km | mi | mm | um | yd

Details

Maximum spool stroke between ports B and T.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`max_spool_travel_bt`
Evaluatable	Yes

# B-T maximum orifice area — maximum area between ports B and T
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area between ports B and T in the fully open position.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization value Linear - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`max_area_bt`
Evaluatable	Yes

# B-T orifice spool travel vector — vector of spool relative positions
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions. The dimension of the vector corresponds to the B-T orifice area vector. The values are listed in ascending order and the first element must be 0. Linear interpolation is used between the data points in the table.

Dependencies

To use this parameter, set the parameters to:

Area characteristics value Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_bt`
Evaluatable	Yes

# B-T orifice area vector — vector of values of the channel cross-sectional area
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Vector of channel cross-sectional area values for the tabular parameterization of the valve area. The dimension of the vector corresponds to the B-T orifice spool travel vector. The values are listed in ascending order and must be greater than 0.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value `Tabulated data - Area vs. spool travel'.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1e-10, 1e-5, 4e-5, 6e-5, 1e-4] m^2`
Program usage name	`valve_area_vector_bt`
Evaluatable	Yes

# B-T orifice spool travel vector, ds — vector of values of the spool relative position
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions for tabular parameterization by volume flow. The dimension of the spool position vector corresponds to the differential pressure vector B-T orifice pressure drop vector,dp and the volumetric flow rate table B-T orifice volumetric flow rate table, q(s,dp). The values are listed in ascending order and the first element must be 0. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 1.25e-3, 2.5e-3, 3.75e-3, 5e-3] m`
Program usage name	`spool_travel_vector_2D_bt`
Evaluatable	Yes

# B-T orifice pressure drop vector, dp — vector of differential pressure values
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for tabular parameterization by volume flow. The differential pressure vector corresponds to the spool position vector B-T orifice spool travel vector, ds and the volumetric flow rate table B-T orifice volumetric flow rate table, q(ds,dp). The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D_bt`
Evaluatable	Yes

# B-T orifice volumetric flow rate table, q(ds,dp) — table of volumetric flow rates
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Matrix to of volume flow rates corresponding to differential pressure and spool position values. to - dimensions of the corresponding vectors:

- number of elements in the spool position vector B-T orifice spool travel vector, ds.
- number of elements in the pressure drop vector B-T orifice pressure drop vector, dp.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to `Different for each flow path'.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-1e-8 2.2e-8 2.8e-8 3.4e-8; -9e-6 1.5e-4 2e-4 2.4e-4; -3.6e-4 6.3e-4 8.1e-4 9.6e-4; -5.4e-4 9.4e-4 1.2e-3 1.4e-3; -9.1e-4 1.6e-3 2.0e-3 2.4e-3] m^3/s`
Program usage name	`Vdot_matrix_2D_bt`
Evaluatable	Yes

# B-T constant orifice area — cross-sectional area of the permanently open channel
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of a channel defined as open in both positions.

Dependencies

To use this parameter, set for parameters:

Area characteristics to Different for each flow path.
Orifice parameterization to Linear - area vs. spool travel or Tabulated data - Area vs. spool travel.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

This parameter is enabled only if the B-T channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-4 m^2`
Program usage name	`area_fixed_bt`
Evaluatable	Yes

# B-T constant orifice pressure drop vector — vector of differential pressure values for a permanently open channel
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for a channel set open in both positions. The dimension of the differential pressure vector corresponds to the B-T constant orifice volumetric flow rate vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

This parameter is enabled only if the B-T channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[-0.1, 0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_fixed_bt`
Evaluatable	Yes

# B-T constant volumetric flow rate vector — vector of values of the volume constant open channel
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Vector of volumetric flow rate values for a channel defined open in both positions. The dimension of the pressure drop vector corresponds to the B-T constant orifice pressure drop vector. The values are listed in ascending order. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the parameters to:

Area characteristics to Different for each flow path.
Orifice parameterization value Tabulated data - Volumetric flow rate vs. spool travel and pressure drop.
Positive spool position open connections or Negative spool position open connections one of the following values:
- B-T only.
- `P-A and B-T
- `P-A, P-B, A-T, and B-T'.

This parameter is enabled only if the B-T channel is present in both the Positive spool position open connections and Negative spool position open connections parameters.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[-9e-4, 1.6e-3, 2.0e-3, 2.4e-3] m^3/s`
Program usage name	`Vdot_vector_fixed_bt`
Evaluatable	Yes