Orifice (TL)

An opening of constant or variable area in a thermal liquid network.

blockType: EngeeFluids.ThermalLiquid.Orifices.LocalRestriction

Orifice (TL)

Path in the library:

/Physical Modeling/Fluids/Thermal Liquid/Valves & Orifices/Orifices/Orifice (TL)

Variable Orifice (TL)

Path in the library:

/Physical Modeling/Fluids/Thermal Liquid/Valves & Orifices/Orifices/Variable Orifice (TL)

Description

The Orifice (TL) unit simulates the flow through a local restriction with a constant or variable opening area. For variable area openings, a control element connected to the S port sets the opening position. The opening area is varied linearly or using an interpolation table.

orifice 1 en

The mass conservation equation in the block is realised as follows:

This mass conservation equation implies an increase in velocity when the area decreases and a decrease in velocity when the area of the bore increases. According to Bernoulli’s principle, this change in velocity results in a region of reduced pressure in the orifice and increased pressure in the expansion zone. The resulting increase in pressure, called pressure recovery, depends on the discharge coefficient of the orifice and the ratio of orifice to port area.

Holes with constant cross-sectional area

If `Constant' is selected for the Orifice type parameters, the block simulates flow through an orifice with a constant opening area , it is assumed that its value does not change during the simulation.

Parameterization of flow through orifice area value

If Orifice area is selected for the Orifice parameterization parameter, the block calculates the mass flow rate as:

where

- is the discharge coefficient Discharge coefficient;
- instantaneous open orifice area;
- cross-sectional area at ports A and B, Cross-sectional area at ports A and B;
- average density of the liquid.

Pressure drop and critical pressure drop are calculated in the same way for constant and variable area ports.

Table parameterization by flow rate

If Tabulated data - Volumetric flow rate vs. pressure drop or Tabulated data - Mass flow rate vs. pressure drop is selected for the Orifice parameterization, the flow rate is determined based on the tabulated pressure drop values , which are specified in the Pressure drop vector parameter. If you specify only non-negative values for the flow rate and pressure drop vectors, the block extrapolates the table to negative values. The flow value is interpolated from this extended table.

If the flow and differential pressure vectors contain both negative and positive values but do not contain 0, the block will set the origin to the vectors to ensure that there is no non-zero flow when the differential pressure is 0, which is unphysical.

Openings with variable cross-sectional area

If Variable is selected for the Orifice type parameters, the block will simulate flow through an orifice with a variable opening area.

If the Opening orientation parameters are set to Positive control member displacement opens orifice', the orifice opens when the signal at port S is positive. If the Opening orientation parameters are set to `Negative control member displacement opens orifice, the orifice opens when the signal at port S is negative. If the signal is positive in both cases, the opening of the orifice is determined by the magnitude of the signal.

Linear parameterization of the hole area value depending on the position of the control member

If `Linear - Area vs. control member position' is selected for the Orifice parameterization, the orifice area depends on the position of the control member and the ratio of the orifice area to the maximum position of the control member:

where

- is the position of the control member when the orifice is fully closed;
- value of the Control member travel between closed and open orifice parameters;
- value of parameter Maximum orifice area;
- value of parameter Leakage area;
- value of the Opening orientation parameters.

The volumetric flow rate can be determined from the pressure/flow ratio:

where is the value of the parameter Cross-sectional area at ports A and B.

For linear parameterization, when the orifice is in the nearly open or nearly closed position, numerical stability can be maintained in the simulation by adjusting the Smoothing factor parameter. If the Smoothing factor parameters are not zero, a smooth change in the orifice area between and is achieved.

Table parameterization of the hole area value as a function of the position of the control element

If Tabulated data - Area vs. control member position is selected for the Orifice parameterization, the bore area of is interpolated from the tabulated values for bore area and control member position that you can provide.

As with the Linear data - Area vs. control member position parameterization, the volume flow rate can be determined from the pressure-flow ratio: ,

where is:

- the last element of the Orifice area vector if the orifice is larger than the maximum specified orifice;
- the first element of the Orifice area vector if the hole is smaller than the minimum specified hole;
if the calculated area is between the limits of the Orifice area vector.

The value of depends on the position of the control element arriving at the S port. The block queries between data points using linear interpolation and uses nearest extrapolation for points outside the table boundaries.

Table parameterization by volumetric flow rate as a function of the position of the control element and pressure drop

If The Tabulated data - Volumetric flow rate vs. control member position and pressure drop is selected for the Orifice parameterization parameter, the volumetric flow rate values are interpolated directly from a user-supplied volumetric flow rate table based on the control member position and pressure drop across the orifice. The block queries between data points using linear interpolation and uses nearest extrapolation with respect to control member position and linear extrapolation with respect to pressure drop.

This data may include negative pressure drop and negative opening values. If a negative pressure drop is included in the data set, the volumetric flow rate will change direction. However, the flow rate will remain unchanged for negative opening values.

If the Pressure drop vector parameter, dp does not contain 0 and the Volumetric flow rate table parameter, q(s,dp) does not contain the corresponding 0 column, the block adds them to ensure that there is no non-zero flow rate at a pressure drop equal to 0, which is unphysical.

Table parameterization by mass flow rate as a function of control element position and pressure drop

If Tabulated data - Mass flow rate vs. control member position and pressure drop is selected for the Orifice parameterization parameter, the mass flow rate values are calculated directly from the control member position and pressure drop. The relationship between these three variables can be non-linear and is tabulated in the parameters Control member position vector, s, Pressure drop vector, dp and Mass flow rate table, mdot(s,dp):

where - tabular values of mass flow rate depending on the control member position and pressure drop .

The mass flow rate is corrected for temperature and pressure by the relationship , where is the average density of the liquid in the orifice and is the initial density for the parameters Reference inflow temperature and Reference inflow pressure.

Pressure losses

Pressure loss describes the reduction in pressure in a valve due to a reduction in area. The pressure loss term, , is calculated as:

Pressure loss, , accounts for the reduction in pressure in the orifice due to a reduction in area and is calculated as:

Pressure recovery describes the positive change in orifice pressure due to an increase in area. To disregard pressure recovery, uncheck the Pressure recovery box. In this case, will be set to 1.

Critical pressure drop

The critical pressure drop is the pressure drop determined from the value of the critical Reynolds number , which is the transition point between laminar and turbulent fluid flow:

Conservation of Energy

The unit treats the orifice as an adiabatic component. There is no heat exchange between the fluid and the wall that surrounds it. The fluid does not do any work as it moves from the inlet to the outlet. Under these assumptions, energy can only flow by convection through ports A and B. According to the principle of conservation of energy, the sum of energy flows in the ports must always be zero:

where is defined as the energy flux into the hole through one of the ports (A or B).

Ports

Conserving

# A — thermal liquid port
thermal liquid

Details

Thermal liquid port, corresponds to the inlet or outlet of the port. This unit has no internal directionality.

Program usage name

port_a

# B — thermal liquid port
thermal liquid

Details

Thermal liquid port, corresponds to the inlet or outlet of the port. This unit has no internal directionality.

Program usage name

port_b

Input

# S — actuator displacement
scalar

Details

Input move port of the control that specifies the opening of the hole.

Dependencies

To use this port, set the Orifice type parameters to Variable.

Data types	`Float64`.
Complex numbers support	No

Parameters

# Orifice type — hole type
Constant | Variable

Details

The type of hole that determines whether the area of the hole can vary:

Constant — the hole area is constant during the simulation.
Variable — The hole area varies depending on the input signal coming to port S.

Values	`Constant` \| `Variable`
Default value	`—`
Program usage name	`orifice_type`
Evaluatable	No

# Orifice parameterization — parameterization of a hole with a constant area
Orifice area | Tabulated data - Volumetric flow rate vs. pressure drop | Tabulated data - Mass flow rate vs. pressure drop

Details

The method used for parameterization. Default value Orifice area determines the flow rate value through the hole area value. Values Tabulated data - Volumetric flow rate vs. pressure drop and Tabulated data - Mass flow rate vs. pressure drop they allow you to set the general nonlinear dependence of the flow rate on the pressure drop in tabular form.

Dependencies

To use this parameter, set the Orifice type parameter to Constant.

Values	`Orifice area` \| `Tabulated data - Volumetric flow rate vs. pressure drop` \| `Tabulated data - Mass flow rate vs. pressure drop`
Default value	`Orifice area`
Program usage name	`fixed_restriction_parameterization`
Evaluatable	No

# Orifice parameterization — parameterization of a hole with a variable area
Linear - Area vs. control member position | Tabulated data - Area vs. control member position | Tabulated data - Volumetric flow rate vs. control member position and pressure drop | Tabulated data - Mass flow rate vs. control member position and pressure drop

Details

For holes with variable area, there are four parameterization options.:

Linear - Area vs. control member position — the opening area depends linearly on the position of the control element in relation to the fully open or fully closed opening. The position is set by the value on the S port.
Tabulated data - Area vs. control member position — the opening area is interpolated from the Control member position vector and Orifice area vector based on the position of the control element received at port S.
Tabulated data - Volumetric flow rate vs. control member position and pressure drop — the volumetric flow rate is interpolated from the user-provided parameters Control member position vector, s, Pressure drop vector, dp and Volumetric flow rate table, q(s,dp) based on the position of the control element received at port S and the pressure drop through ports A and B.
Tabulated data - Mass flow rate vs. control member position and pressure drop — the mass flow rate is interpolated from the user-provided parameters Control member position vector, s, Pressure drop vector, dp, and Mass flow rate table, mdot(s,dp) based on the position of the control element received at port S and the pressure drop through ports A and B.

Dependencies

To use this parameter, set the Orifice type parameter to Variable.

Values	`Linear - Area vs. control member position` \| `Tabulated data - Area vs. control member position` \| `Tabulated data - Volumetric flow rate vs. control member position and pressure drop` \| `Tabulated data - Mass flow rate vs. control member position and pressure drop`
Default value	`Linear - Area vs. control member position`
Program usage name	`variable_restriction_parameterization`
Evaluatable	No

# Orifice area — hole area
m^2 | um^2 | mm^2 | cm^2 | km^2 | in^2 | ft^2 | yd^2 | mi^2 | ha | ac

Details

The cross-sectional area of the hole.

Dependencies

To use this parameter, set the Orifice type parameter to Constant, and for the Orifice parameterization parameter , the value Orifice area.

Units	`m^2` \| `um^2` \| `mm^2` \| `cm^2` \| `km^2` \| `in^2` \| `ft^2` \| `yd^2` \| `mi^2` \| `ha` \| `ac`
Default value	`1e-3 m^2`
Program usage name	`fixed_orifice_area`
Evaluatable	Yes

# Pressure drop vector — vector of pressure drop values
Pa | uPa | hPa | kPa | MPa | GPa | kgf/m^2 | kgf/cm^2 | kgf/mm^2 | mbar | bar | kbar | atm | ksi | psi | mmHg | inHg

Details

Vector of differential pressure values for tabular flow parameterization. The values of the differential pressure vector correspond to the flow values of the Volumetric flow rate vector or Mass flow rate vector. The values of the pressure drop vector are listed in ascending order. The flow value is interpolated from the Volumetric flow rate vector or Mass flow rate vector parameters, which depend on the Pressure drop vector parameter.

Dependencies

To use this parameter, set the Orifice type parameter to Constant, and for the Orifice parameterization parameter , the value Tabulated data - Volumetric flow rate vs. pressure drop or Tabulated data - Mass flow rate vs. pressure drop.

Units	`Pa` \| `uPa` \| `hPa` \| `kPa` \| `MPa` \| `GPa` \| `kgf/m^2` \| `kgf/cm^2` \| `kgf/mm^2` \| `mbar` \| `bar` \| `kbar` \| `atm` \| `ksi` \| `psi` \| `mmHg` \| `inHg`
Default value	`[-4.0, -3.0, -2.0, -1.0, -0.5, 0.0, 0.5, 1.0, 2.0, 3.0, 4.0] MPa`
Program usage name	`delta_p_fixed_vector_1D`
Evaluatable	Yes

# Volumetric flow rate vector — vector of volume flow values
m^3/s | mm^3/s | cm^3/s | m^3/hr | m^3/min | l/hr | l/min | l/s | gal/hr | gal/min | gal/s | ft^3/hr | ft^3/min | ft^3/s

Details

Vector of volume flow values for tabular parameterization by volume flow. The volume flow values correspond to the differential pressure values in the Pressure drop vector parameter. The flow rate value is interpolated from the Volumetric flow rate vector parameter, which depends on the Pressure drop vector parameter.

Dependencies

To use this parameter, set the Orifice type parameter to Constant, and for the Orifice parameterization parameter , the value Tabulated data - Volumetric flow rate vs. pressure drop.

Units	`m^3/s` \| `mm^3/s` \| `cm^3/s` \| `m^3/hr` \| `m^3/min` \| `l/hr` \| `l/min` \| `l/s` \| `gal/hr` \| `gal/min` \| `gal/s` \| `ft^3/hr` \| `ft^3/min` \| `ft^3/s`
Default value	`[-2.44, -2.12, -1.68, -1.22, -0.84, 0.0, 0.85, 1.21, 1.70, 2.09, 2.41] * 1e-3 m^3/s`
Program usage name	`Vdot_fixed_vector_1D`
Evaluatable	Yes

Details

A vector of mass flow values for tabular parameterization by mass flow. The mass flow values correspond to the pressure drop values in the Pressure drop vector parameter. The flow value is interpolated from the Mass flow rate vector parameter, which depends on the Pressure drop vector parameter.

Dependencies

To use this parameter, set the Orifice type parameter to Constant, and for the Orifice parameterization parameter , the value Tabulated data - Mass flow rate vs. pressure drop.

Units	`kg/s` \| `kg/hr` \| `kg/min` \| `g/hr` \| `g/min` \| `g/s` \| `t/hr` \| `lbm/hr` \| `lbm/min` \| `lbm/s`
Default value	`[-2.44, -2.12, -1.68, -1.22, -0.84, 0.0, 0.85, 1.21, 1.7, 2.09, 2.41] kg/s`
Program usage name	`mdot_fixed_vector_1D`
Evaluatable	Yes

# Control member position at closed orifice — displacement of the control element
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The initial displacement of the control element when the opening is completely closed.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position.

Units	`m` \| `um` \| `mm` \| `cm` \| `km` \| `in` \| `ft` \| `yd` \| `mi` \| `nmi`
Default value	`0.0 m`
Program usage name	`min_control_displacement`
Evaluatable	Yes

# Control member travel between closed and open orifice — maximum stroke of the control element
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The maximum distance that the control element passes between the closed and open openings.

The hole is fully open when the parameters Control member position at closed orifice and Control member travel between closed and open orifice are combined.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position.

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

# Opening orientation — the direction of movement of the element opening the hole
Positive control member displacement opens orifice | Negative control member displacement opens orifice

Details

The direction of movement of the element opening the variable hole. A positive orientation means that a positive signal on the port S opens the hole. A negative direction means that a negative signal on S opens the hole.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position.

Values	`Positive control member displacement opens orifice` \| `Negative control member displacement opens orifice`
Default value	`Positive control member displacement opens orifice`
Program usage name	`opening_orientation`
Evaluatable	No

# Maximum orifice area — maximum opening area of the hole
m^2 | um^2 | mm^2 | cm^2 | km^2 | in^2 | ft^2 | yd^2 | mi^2 | ha | ac

Details

The maximum area of the hole during the simulation.

When using Tabulated data - Area vs. control member position, the maximum area of the hole is the last element of the Orifice area vector.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position.

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

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

Details

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

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position.

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

# Control member position vector — vector of positions of control elements
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

Vector of positions of control elements for tabular parameterization of the hole area. The position values of the control elements correspond to the values of the Orifice area vector. The elements of the vector must be strictly monotonically increasing or decreasing. The hole area is interpolated from the Orifice area vector parameter, which depends on the Control member position vector parameter.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Tabulated data - Area vs. control member position.

Units	`m` \| `um` \| `mm` \| `cm` \| `km` \| `in` \| `ft` \| `yd` \| `mi` \| `nmi`
Default value	`[0.0, 2.0e-3, 4.0e-3, 7.0e-3, 1.7e-2] m`
Program usage name	`control_displacement_vector_1D`
Evaluatable	Yes

# Orifice area vector — vector of values of the hole opening area
m^2 | um^2 | mm^2 | cm^2 | km^2 | in^2 | ft^2 | yd^2 | mi^2 | ha | ac

Details

A vector of hole area values for tabular parameterization of the hole area. The values in this vector correspond to the elements in the Control member position vector parameter. If the values of the vector increase, then the first element of this vector is the leakage area of the hole, and the last element is the maximum area of the hole. If the values of the vector decrease, then the first element of this vector is the maximum area of the hole, and the last element is the area of the leak. The hole area is interpolated from the Orifice area vector parameter, which depends on the Control member position vector parameter.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Tabulated data - Area vs. control member position.

Units	`m^2` \| `um^2` \| `mm^2` \| `cm^2` \| `km^2` \| `in^2` \| `ft^2` \| `yd^2` \| `mi^2` \| `ha` \| `ac`
Default value	`[1.0e-9, 2.0352e-7, 4.0736e-5, 1.1438e-4, 3.4356e-4] m^2`
Program usage name	`orifice_area_vector_1D`
Evaluatable	Yes

# Discharge coefficient — the discharge coefficient

Details

A correction factor that takes into account discharge losses.

Dependencies

To use this parameter, set:

for the Orifice type parameter, the value Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position or Tabulated data - Area vs. control member position.
for the Orifice type parameter, the value Constant, and for the Orifice parameterization parameter to the value Orifice area.

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

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

Details

The upper limit of the Reynolds number for laminar flow through the hole.

Dependencies

To use this parameter, set:

for the Orifice type parameter, the value Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position or Tabulated data - Area vs. control member position.
for the Orifice type parameter, the value Constant, and for the Orifice parameterization parameter to the value Orifice area.

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

# Smoothing factor — numerical smoothing coefficient

Details

The numerical smoothing coefficient, which ensures smooth opening by correcting the characteristic of the hole in the almost open and almost closed positions.

The value must be in the range [0, 1].

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position.

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

# Pressure recovery — should the pressure increase be taken into account when expanding the area

Details

Should the pressure increase be taken into account when liquid flows from an area with a smaller cross-sectional area to an area with a larger cross-sectional area.

Dependencies

To use this parameter, set:

for the Orifice type parameter, the value Variable, and for the Orifice parameterization parameter , the value Linear - Area vs. control member position or Tabulated data - Area vs. control member position.
for the Orifice type parameter, the value Constant, and for the Orifice parameterization parameter to the value Orifice area.

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

# Control member position vector, s — position vector of the control element
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

Vector of positions of control elements for tabular parameterization by flow rate. The position values of the control elements correspond to the values of the differential pressure Pressure drop vector, dp and the flow values Volumetric flow rate table, q(s,dp) or Mass flow rate table, mdot(s,dp). A positive offset corresponds to the opening of the hole. The values are listed in ascending order, the first element should be equal to 0. Linear interpolation is used between data points.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for the Orifice parameterization parameter , the value Tabulated data - Volumetric flow rate vs. control member position and pressure drop or Tabulated data - Mass flow rate vs. control member position and pressure drop.

Units	`m` \| `um` \| `mm` \| `cm` \| `km` \| `in` \| `ft` \| `yd` \| `mi` \| `nmi`
Default value	`[0.0, 2.0e-3, 4.0e-3, 7.0e-3, 1.7e-2] m`
Program usage name	`control_displacement_vector_2D`
Evaluatable	Yes

# Pressure drop vector, dp — vector of pressure drop values
Pa | uPa | hPa | kPa | MPa | GPa | kgf/m^2 | kgf/cm^2 | kgf/mm^2 | mbar | bar | kbar | atm | ksi | psi | mmHg | inHg

Details

Vector of differential pressure values for tabular flow parameterization. The differential pressure values correspond to the positions of the control element Control member position vector, s and the flow values Volumetric flow rate table, q(s,dp) or Mass flow rate table, mdot(s,dp). The values are listed in ascending order and must be greater. 0. Linear interpolation is used between data points.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for Orifice parameterization — Tabulated data - Volumetric flow rate vs. control member position and pressure drop or Tabulated data - Mass flow rate vs. control member position and pressure drop.

Units	`Pa` \| `uPa` \| `hPa` \| `kPa` \| `MPa` \| `GPa` \| `kgf/m^2` \| `kgf/cm^2` \| `kgf/mm^2` \| `mbar` \| `bar` \| `kbar` \| `atm` \| `ksi` \| `psi` \| `mmHg` \| `inHg`
Default value	`[0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D`
Evaluatable	Yes

# Volumetric flow rate table, q(s,dp) — table of volume flow values
m^3/s | mm^3/s | cm^3/s | m^3/hr | m^3/min | l/hr | l/min | l/s | gal/hr | gal/min | gal/s | ft^3/hr | ft^3/min | ft^3/s

Details

The matrix on the volume flow rates corresponding to the differential pressure values and the positions of the control element.

Values and — the sizes of the corresponding vectors:

— the number of elements in the pressure drop vector Pressure drop vector, dp.
— the number of elements in the position vector of the control element Control member position vector, s.

Dependencies

Units	`m^3/s` \| `mm^3/s` \| `cm^3/s` \| `m^3/hr` \| `m^3/min` \| `l/hr` \| `l/min` \| `l/s` \| `gal/hr` \| `gal/min` \| `gal/s` \| `ft^3/hr` \| `ft^3/min` \| `ft^3/s`
Default value	`[1.7e-05 2e-05 2.6e-05; 0.0035 0.0045 0.0053; 0.7 0.9 1.06; 1.96 2.5 3.0; 6.0 7.7 9.13] * 1e-3 m^3/s`
Program usage name	`Vdot_matrix_2D`
Evaluatable	Yes

Details

The matrix on the mass flow rates corresponding to the differential pressure values and the positions of the control element.

Values and — the sizes of the corresponding vectors:

— the number of elements in the pressure drop vector Pressure drop vector, dp.
— the number of elements in the position vector of the control element Control member position vector, s.

Dependencies

To use this parameter, set the Orifice type parameter to Variable, and for Orifice parameterization — Tabulated data - Mass flow rate vs. control member position and pressure drop.

Units	`kg/s` \| `kg/hr` \| `kg/min` \| `g/hr` \| `g/min` \| `g/s` \| `t/hr` \| `lbm/hr` \| `lbm/min` \| `lbm/s`
Default value	`[1.7e-05 2e-05 2.6e-05; 0.0035 0.0045 0.0053; 0.7 0.9 1.06; 1.96 2.5 3.0; 6.0 7.7 9.13] kg/s`
Program usage name	`mdot_matrix_2D`
Evaluatable	Yes

Details

The nominal inlet temperature, taking into account absolute zero, at which tabular data should be indicated. This parameter is used to adjust the mass flow according to the temperature measured during the simulation.

Dependencies

To use this parameter, set:

for the Orifice type parameter, the value Variable, and for the Orifice parameterization parameter , the value Tabulated data - Mass flow rate vs. control member position and pressure drop.
for the Orifice type parameter, the value Constant, and for the Orifice parameterization parameter , the value Tabulated data - Mass flow rate vs. pressure drop.

Units	`K` \| `degC` \| `degF` \| `degR` \| `deltaK` \| `deltadegC` \| `deltadegF` \| `deltadegR`
Default value	`293.15 K`
Program usage name	`T_inflow_ref`
Evaluatable	Yes

# Reference inflow pressure — the inlet pressure at which tabular data must be specified
Pa | uPa | hPa | kPa | MPa | GPa | kgf/m^2 | kgf/cm^2 | kgf/mm^2 | mbar | bar | kbar | atm | ksi | psi | mmHg | inHg

Details

The nominal inlet pressure, taking into account the absolute zero, at which tabular data should be indicated. This parameter is used to adjust the mass flow according to the pressure measured during the simulation.

Dependencies

To use this parameter, set:

for the Orifice type parameter, the value Variable, and for the Orifice parameterization parameter , the value Tabulated data - Mass flow rate vs. control member position and pressure drop.
for the Orifice type parameter, the value Constant, and for the Orifice parameterization parameter , the value Tabulated data - Mass flow rate vs. pressure drop.

Units	`Pa` \| `uPa` \| `hPa` \| `kPa` \| `MPa` \| `GPa` \| `kgf/m^2` \| `kgf/cm^2` \| `kgf/mm^2` \| `mbar` \| `bar` \| `kbar` \| `atm` \| `ksi` \| `psi` \| `mmHg` \| `inHg`
Default value	`0.101325 MPa`
Program usage name	`p_inflow_ref`
Evaluatable	Yes

# Cross-sectional area at ports A and B — the area at the entrance or exit of the hole
m^2 | um^2 | mm^2 | cm^2 | km^2 | in^2 | ft^2 | yd^2 | mi^2 | ha | ac

Details

The cross-sectional area of the inlet and outlet openings is A and B. This area is used when calculating the mass flow through the hole.

Units	`m^2` \| `um^2` \| `mm^2` \| `cm^2` \| `km^2` \| `in^2` \| `ft^2` \| `yd^2` \| `mi^2` \| `ha` \| `ac`
Default value	`0.01 m^2`
Program usage name	`port_area`
Evaluatable	Yes