Engee documentation

Variable-Displacement Motor (TL)

A variable-displacement hydraulic motor in a heat-conducting fluid network.

blockType: EngeeFluids.ThermalLiquid.Turbomachinery.VariableDisplacementMotor

variable displacement motor tl

Path in the library:

/Physical Modeling/Fluids/Thermal Liquid/Pumps & Motors/Variable-Displacement Motor (TL)

Description

Block Variable-Displacement Motor (TL) It is a device that receives energy from a heat-conducting liquid network and transmits it to a mechanical network. The working volume of the hydraulic motor fluid can change during simulation, and is sent as a signal to port D.

Ports A and B represent the inlet and outlet ports of the hydraulic motor. Ports R and C represent the drive shaft and the hydraulic motor housing. The liquid flow can be directed from port A to port B (forward mode) or from port B to port A (reverse mode). Operation in the hydraulic motor mode occurs when the pressure drops in the flow direction. The pump operation mode is realized when the pressure increases in the flow direction.

The operating modes are shown in the diagram.

variable displacement motor il 1

The unit has eight operating modes. The operating mode depends on the pressure drop from port A to port B , angular velocity and the working volume. In the diagram above, these modes are shown as octants of the diagram. :

  • Mode 1, direct hydraulic motor mode: the flow from port A to port B causes a decrease in pressure from port A to port B and a positive angular velocity of the shaft.

  • Mode 2, Reverse pump mode: the negative angular velocity of the shaft causes pressure to rise from port B to port A and flow from port B to port A.

  • Mode 3, reverse hydraulic motor mode: the flow from port B to port A causes a decrease in pressure from port B to port A and a negative angular velocity of the shaft.

  • Mode 4, Direct pump mode: the positive angular velocity of the shaft causes pressure to rise from port A to port B and flow from port A to port B.

  • Mode 5, Reverse pump mode: the positive angular velocity of the shaft causes pressure to rise from port B to port A and flow from port B to port A.

  • Mode 6, direct hydraulic motor mode: the flow from port A to port B causes a decrease in pressure from port A to port B and a negative angular velocity of the shaft.

  • Mode 7, Direct pump mode: the negative angular velocity of the shaft causes pressure to rise from port A to port B and flow from port A to port B.

  • Mode 8, reverse hydraulic motor mode: the flow from port B to port A causes a decrease in pressure from port B to port A and a positive angular velocity of the shaft.

The time constant of the hydraulic motor is considered insignificant compared to the time constant of the system. It is assumed that the hydraulic motor reaches a steady state almost instantly and is considered as a quasi-stationary component.

Flow rate and torque

The mass flow rate of the hydraulic motor is:

where

  • — actual mass consumption;

  • — ideal mass flow rate;

  • — mass consumption of internal leakage.

The torque of the hydraulic motor is:

where

  • — actual torque;

  • — perfect torque;

  • — the moment of friction.

The ideal flow rate and ideal torque are calculated as




where

  • — the average value of the liquid density in the ports of the heat-conducting liquid A and B;

  • — the working volume supplied as a scalar to the port S;

  • — angular rotation speed of the shaft;

  • — pressure drop from inlet to outlet.

Analytical parameterization of leakage and friction moment

If for the parameter Leakage and friction parameterization the value is set Analytical, then the leakage rate is:

and the moment of friction is calculated as:

where

  • — the Hagen-Poiseuille coefficient for laminar flows. The unit calculates this coefficient from the specified nominal parameters;

  • — the average dynamic viscosity of the heat-conducting liquid in the ports;

  • — average density of liquid in ports;

  • — the coefficient of dependence of the moment of friction on the pressure at the nominal working volume, which is determined by the value of the parameter Mechanical efficiency at nominal conditions, :

    where — the moment of friction under nominal conditions:

  • — the value of the block parameter Nominal displacement;

  • — parameter value No-load torque;

  • — parameter value Nominal shaft angular velocity. This is the angular velocity at which the nominal volumetric efficiency is set.;

  • — parameter value Nominal pressure drop. This value represents the pressure drop at which the nominal volumetric efficiency is set.;

The unit determines the Hagen-Poiseuille coefficient based on the nominal parameters of the liquid and components

where

  • — parameter value Nominal dynamic viscosity. This value represents the dynamic viscosity at which the nominal volumetric efficiency is set.;

  • — parameter value Volumetric efficiency at nominal conditions.

Tabular parameterization

When using tabular data for the efficiency or losses of a hydraulic motor, you can specify data for one or more operating modes. The signs of the tabular data determine the operating mode of the block. If data is provided for less than four operating modes, the block calculates additional data for another mode(s), expanding the specified data into the remaining quadrants.

Table data — parameterization of volumetric and mechanical efficiency_

If for the parameter Leakage and friction parameterization the value is set Tabulated data - volumetric and mechanical efficiencies, then the block performs parameterization based on tabular data for volumetric and mechanical efficiency.

The leakage rate is:

and the moment of friction is:

where

  • — numerical smoothing parameter for the transition process from the hydraulic motor to the pump;

  • — leakage rate in pump mode;

  • — leakage rate in hydraulic motor mode;

  • — the moment of friction in the pump mode;

  • — the moment of friction in the hydraulic motor mode.

Smoothing parameter is defined by a hyperbolic function

where

  • — parameter value Pressure drop threshold for motor-pump transition;

  • — parameter value Angular velocity threshold for motor-pump transition;

  • — parameter value Displacement threshold for motor-pump transition.

The volumetric flow rate is calculated based on volumetric efficiency, a value that is set in tabular form in the using the Volumetric efficiency table block parameter.

When operating in pump mode, the leakage rate is:

where — volumetric efficiency obtained by interpolation or extrapolation of tabular data.

Similarly, when operating in the hydraulic motor mode, the leakage rate is:

The moment of friction is calculated in a similar way from the mechanical efficiency, a value that is set in tabular form in the area of using the block parameter Mechanical efficiency table, e_m(dp,w,D).

When operating in pump mode, the friction moment is:

where — mechanical efficiency obtained by interpolation or extrapolation of tabular data.

Similarly, when operating in the hydraulic motor mode, the friction moment is:

Table data — parameterization of volume and mechanical losses_

If for the parameter Leakage and friction parameterization the value is set Tabulated data - volumetric and mechanical losses, then the volume flow rate of the leak is set directly in tabular form in the area :

The mass flow rate of the leak is calculated from the volume flow rate:

The moment of friction is:

where and — volumetric and mechanical losses obtained by interpolation or extrapolation of tabular data specified in the parameters Volumetric loss table, q_loss(dp,w,D) and Mechanical loss table, torque_loss(dp,w,D).

Parameterization via the input signal

If for the parameter Leakage and friction parameterization the value is set Input signal - volumetric and mechanical efficiencies, then ports EV and EM are enabled. Internal leakage and shaft friction are calculated in the same way as with parameterization Tabulated data - volumetric and mechanical efficiencies, except that the efficiency values are and They are delivered directly to the EV and EM ports, respectively.

Efficiency is a positive value with a value between 0 and 1'. The values of the input signals outside these boundaries are set equal to the nearest boundary (`0 for inputs less than 0 and 1 for inputs greater than 1). Volumetric and mechanical efficiency vary between user-defined minimum and maximum values. Any values below or above this range will take the minimum and maximum set values, respectively.

If for the parameter Leakage and friction parameterization the value is set Input signal - volumetric and mechanical losses, then ports LV and LM are enabled. These ports receive the values of the leakage current and the moment of friction in the form of positive scalars.

The input values are expected to be positive. The unit automatically sets the signs based on the operating conditions set during the simulation, that is, from the quadrant. , in which the component is running.

Energy conservation

The mechanical work performed by a hydraulic motor is related to the exchange of energy. The energy conservation equation has the form:

where

  • and — energy flows in ports A and B respectively;

  • — hydraulic power of the hydraulic motor. It is a function of the pressure difference between the ports of the hydraulic motor: .

The mechanical power of a hydraulic motor is determined based on the torque and angular velocity :

Assumptions and limitations

  • The compressibility of the liquid can be neglected.

  • The load on the hydraulic motor shaft due to inertia, friction and springs is negligible.

Ports

Conserving

# R — mechanical port
`rotational mechanics

Details

Angular velocity of rotation and torque of a shaft.

Program usage name

rod_flange

# C — mechanical port
`rotational mechanics

Details

Angular velocity of rotation and torque of the body.

Program usage name

case_flange

# A — thermal liquid port
thermal liquid

Details

The fluid inlet or outlet port in a hydraulic motor.

Program usage name

port_a

# B — thermal liquid port
thermal liquid

Details

The fluid inlet or outlet port of a pump.

Program usage name

port_b

Input

# D — working volume
scalar

Details

The volume of fluid in m3/rad passing through a hydraulic motor, as a scalar.

Data types

Float64.
Complex numbers support

No

# EV — volumetric efficiency
scalar

Details

Volumetric efficiency specified as a scalar. The value must be in the range from 0 to 1.

Dependencies

To use this port, set parameters Leakage and friction parameterization value Input signal - volumetric and mechanical efficiencies.

Data types

Float64.
Complex numbers support

No

# EM — mechanical efficiency
scalar

Details

The mechanical efficiency of the hydraulic motor, given as a scalar. The value must be in the range from 0 to 1.

Dependencies

To use this port, set parameters Leakage and friction parameterization value Input signal - volumetric and mechanical efficiencies.

Data types

Float64.
Complex numbers support

No

# LV — leakage volume flow rate
scalar

Details

Hydraulic motor losses, in m3/s, given as a scalar.

Dependencies

To use this port, set the parameters to Leakage and friction parameterization value Input signal - volumetric and mechanical losses.

Data types

Float64.
Complex numbers support

No

# LM — friction moment
scalar

Details

The mechanical losses of the pump, in N⋅m, given as a scalar.

Dependencies

To use this port, set parameter Leakage and friction parameterization value Input signal - volumetric and mechanical losses.

Data types

Float64.
Complex numbers support

No

Parameters

Parameters

# Leakage and friction parameterization — method for calculating leakage rate and friction moment
Analytical | Tabulated data - volumetric and mechanical efficiencies | Tabulated data - volumetric and mechanical losses | Input signal - volumetric and mechanical efficiencies | Input signal - volumetric and mechanical losses

Details

Parameterization of the characteristics of leakage and friction of the hydraulic motor.

  • Analytical — the leakage rate and the friction moment are calculated using analytical equations.

  • Tabulated data - volumetric and mechanical efficiencies — volumetric and mechanical efficiency are calculated according to user-defined parameters Pressure drop vector, dp and Shaft angular velocity vector, w and are interpolated based on the corresponding two-dimensional tables. Volumetric efficiency table, e_v(dp,w,D) and Mechanical efficiency table, e_m(dp,w).

  • Tabulated data - volumetric and mechanical loss — leakage flow rate and friction moment are calculated according to user-defined parameters Pressure drop vector, dp and Shaft angular velocity vector, w and are interpolated based on the corresponding two-dimensional tables. Volumetric loss table, q_loss(dp,w,D) and Mechanical loss table, torque_loss(dp,w,D).

  • Input signal - volumetric and mechanical efficiencies — Volumetric and mechanical efficiency are transmitted as signals to the EV and EM ports, respectively.

  • Input signal - volumetric and mechanical loss — the leakage flow rate and the friction moment are sent as signals to the ports LV and LM, respectively.

Values

Analytical | Tabulated data - volumetric and mechanical efficiencies | Tabulated data - volumetric and mechanical losses | Input signal - volumetric and mechanical efficiencies | Input signal - volumetric and mechanical losses
Default value

Analytical
Program usage name

leakage_and_friction_parameterization
Evaluatable

No

# Nominal displacement — nominal working volume
m^3/rad | mm^3/rad | cm^3/rad | km^3/rad | m^3/deg | cm^3/rev | m^3/rev | l/rad | l/rev | in^3/rad | ft^3/rad | gal/rad | igal/rad | in^3/deg | in^3/rev | gal/rev

Details

The amount of fluid supplied to the motor for a given shaft rotation under nominal operating conditions.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

Units

m^3/rad | mm^3/rad | cm^3/rad | km^3/rad | m^3/deg | cm^3/rev | m^3/rev | l/rad | l/rev | in^3/rad | ft^3/rad | gal/rad | igal/rad | in^3/deg | in^3/rev | gal/rev
Default value

30.0 cm^3/rev
Program usage name

nominal_displacement
Evaluatable

Yes

# Nominal shaft angular velocity — nominal angular velocity of the shaft
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

Angular velocity of the shaft under nominal operating conditions.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

Units

rad/s | deg/s | rad/min | deg/min | rpm | rps
Default value

1800.0 rpm
Program usage name

w_nominal
Evaluatable

Yes

# Nominal pressure drop — nominal pressure drop between inlet and outlet
Pa | uPa | hPa | kPa | MPa | GPa | kgf/m^2 | kgf/cm^2 | kgf/mm^2 | mbar | bar | kbar | atm | ksi | psi | mmHg | inHg

Details

Pressure difference between the inlet and outlet of the hydraulic motor under nominal operating conditions. This value under standard operating conditions can usually be found in the manufacturer’s specification. The unit uses this parameter to calculate the internal leakage rate.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

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

10.0 MPa
Program usage name

p_nominal
Evaluatable

Yes

# Nominal dynamic viscosity — nominal dynamic viscosity for a given volumetric efficiency
Pa*s | uPa*s | cP | P | N*s/m^2 | kgf*s/m^2 | reyn

Details

The nominal dynamic viscosity of a liquid corresponding to a given volumetric efficiency. This value under standard operating conditions can usually be found in the manufacturer’s specification. The unit uses this parameter to calculate the internal leakage rate.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

Units

Pa*s | uPa*s | cP | P | N*s/m^2 | kgf*s/m^2 | reyn
Default value

0.9 cP
Program usage name

mu_nominal
Evaluatable

Yes

# Volumetric efficiency at nominal conditions — volumetric efficiency under nominal conditions

Details

The ratio of the actual flow rate to the ideal flow rate under nominal conditions. This value under standard operating conditions can usually be found in the manufacturer’s specification. The unit uses this parameter to calculate the internal leakage rate.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

Default value

0.92
Program usage name

nominal_volumetric_efficiency
Evaluatable

Yes

# Mechanical efficiency at nominal conditions — mechanical efficiency under nominal conditions

Details

The ratio of the actual torque to the ideal torque generated under rated conditions.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

Default value

0.88
Program usage name

nominal_mechanical_efficiency
Evaluatable

Yes

# No-load torque — moment of friction at rest
N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft

Details

The minimum torque value to overcome the seal friction. This torque is a load-independent component of the total friction torque.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Analytical.

Units

N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft
Default value

0.0 N*m
Program usage name

no_load_torque
Evaluatable

Yes

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

Details

A vector of differential pressure values for tabular parameterization of leaks and torque friction. The elements of the vector must be listed in ascending order.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses.

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

[0.1, 1.0, 2.0] MPa
Program usage names

delta_p_vector_efficiency, delta_p_vector_loss
Evaluatable

Yes

# Shaft angular velocity vector, w — vector of angular velocity values for tabular parameterization
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

An angular velocity data vector for tabular parameterization of leakage and friction moment. The elements of the vector must be listed in ascending order.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses.

Units

rad/s | deg/s | rad/min | deg/min | rpm | rps
Default value

[250.0, 500.0, 1000.0, 2000.0, 3000.0, 4000.0] rpm
Program usage names

w_vector_efficiency, w_vector_loss
Evaluatable

Yes

# Displacement vector, D — vector of working volume values for tabular parameterization
m^3/rad | mm^3/rad | cm^3/rad | km^3/rad | m^3/deg | cm^3/rev | m^3/rev | l/rad | l/rev | in^3/rad | ft^3/rad | gal/rad | igal/rad | in^3/deg | in^3/rev | gal/rev

Details

A vector of working volume values for tabular parameterization of leakage and friction moment. The elements of the vector must be listed in ascending order.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses.

Units

m^3/rad | mm^3/rad | cm^3/rad | km^3/rad | m^3/deg | cm^3/rev | m^3/rev | l/rad | l/rev | in^3/rad | ft^3/rad | gal/rad | igal/rad | in^3/deg | in^3/rev | gal/rev
Default value

[-30.0, -19.0, 19.0, 30.0] cm^3/rev
Program usage names

displacement_vector_efficiency, displacement_vector_loss
Evaluatable

Yes

# Volumetric efficiency table, e_v(dp,w,D) — table of volumetric efficiency values

Details

Array on on volumetric efficiency at a given pressure drop of the liquid, the angular velocity of the shaft and the working volume. The block uses linear interpolation between the table elements.

Values , and — these are the sizes of the corresponding vectors:

  • — the number of vector elements in the parameter Pressure drop vector, dp.

  • — the number of vector elements in the parameter Shaft angular velocity vector, w.

  • — the number of vector elements in the parameter Displacement vector, D.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical efficiencies.

Default value

repeat([0.816 0.908 0.954 0.977 0.981 0.984; 0.325 0.663 0.831 0.916 0.925 0.946; 0.137 0.568 0.78 0.892 0.893 0.910], 1, 1, 4)
Program usage name

volumetric_efficiency_matrix
Evaluatable

Yes

# Mechanical efficiency table, e_m(dp,w,D) — table of mechanical efficiencies

Details

Array on on mechanical efficiency at a given pressure drop of the liquid, the angular velocity of the shaft and the working volume. The block uses linear interpolation between the table elements.

Values , and — these are the sizes of the corresponding vectors:

  • — the number of vector elements in the parameter Pressure drop vector, dp.

  • — the number of vector elements in the parameter Shaft angular velocity vector, w.

  • — the number of vector elements in the parameter Displacement vector, D.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical efficiencies.

Default value

repeat([0.996 0.996 0.996 0.996 0.996 0.996; 0.988 0.989 0.989 0.989 0.989 0.990; 0.981 0.981 0.982 0.982 0.983 0.984], 1, 1, 4)
Program usage name

mechanical_efficiency_matrix
Evaluatable

Yes

# Volumetric loss table, q_loss(dp,w,D) — volume loss table
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

Array on on volume losses at a given pressure drop of the liquid, the angular velocity of the shaft and the working volume. The block uses linear interpolation between table elements.

Values , and — these are the sizes of the corresponding vectors:

  • — the number of vector elements in the parameter Pressure drop vector, dp.

  • — the number of vector elements in the parameter Shaft angular velocity vector, w.

  • — the number of vector elements in the parameter Displacement vector, D.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical losses.

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

repeat(1.0e-3 * [0.0230 0.0230 0.0230 0.0230 0.0285 0.0320; 0.0844 0.0842 0.0845 0.0840 0.1125 0.1080; 0.1079 0.1080 0.1100 0.1080 0.1605 0.1800], 1, 1, 4) m^3/s
Program usage name

volumetric_loss_matrix
Evaluatable

Yes

# Mechanical loss table, torque_loss(dp,w,D) — table of mechanical losses
N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft

Details

Array on on mechanical losses at a given pressure drop of the liquid, the angular velocity of the shaft and the working volume. The block uses linear interpolation between table elements.

Values , and — these are the sizes of the corresponding vectors:

  • — the number of vector elements in the parameter Pressure drop vector, dp.

  • — the number of vector elements in the parameter Shaft angular velocity vector, w.

  • — the number of vector elements in the parameter Displacement vector, D.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Tabulated data - volumetric and mechanical losses.

Units

N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft
Default value

repeat([0.0020 0.0020 0.0020 0.0020 0.0020 0.0020; 0.0607 0.0556 0.0556 0.0556 0.0556 0.0505; 0.1937 0.1937 0.1833 0.1833 0.1729 0.1626], 1, 1, 4) N*m
Program usage name

mechanical_loss_matrix
Evaluatable

Yes

# Minimum volumetric efficiency — minimum value of volumetric efficiency

Details

The minimum value of volumetric efficiency. If the input signal is below this value, the volumetric efficiency is set to the minimum volumetric efficiency value.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Input signal - volumetric and mechanical efficiencies.

Default value

1e-3
Program usage name

min_volumetric_efficiency
Evaluatable

Yes

# Maximum volumetric efficiency — maximum volumetric efficiency value

Details

The maximum value of volumetric efficiency. If the input signal exceeds this value, the volumetric efficiency is set to the maximum value of the volumetric efficiency.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Input signal - volumetric and mechanical efficiencies.

Default value

1.0
Program usage name

max_volumetric_efficiency
Evaluatable

Yes

# Minimum mechanical efficiency — minimum value of mechanical efficiency

Details

The minimum value of mechanical efficiency. If the input signal is below this value, the mechanical efficiency is set to the minimum value of the mechanical efficiency.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Input signal - volumetric and mechanical efficiencies.

Default value

1e-3
Program usage name

min_mechanical_efficiency
Evaluatable

Yes

# Maximum mechanical efficiency — maximum value of mechanical efficiency

Details

The maximum value of mechanical efficiency. If the input signal is higher than this value, the mechanical efficiency is set to the maximum value of the mechanical efficiency.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Input signal - volumetric and mechanical efficiencies.

Default value

1.0
Program usage name

max_mechanical_efficiency
Evaluatable

Yes

# Pressure drop threshold for motor-pump transition — threshold pressure for the transition mode
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 threshold value of the pressure drop for switching between the pump and hydraulic motor operating modes. The transition area is defined in the region of 0 MPa between the positive and negative values of the threshold pressure drop. Within this area, the calculated leakage rate and friction moment are adjusted according to the transition term to ensure a smooth transition from one mode to another.

Dependencies

To use this parameter, set for Leakage and friction parameterization one of the values is:

  • Tabulated data - volumetric and mechanical efficiencies;

  • Input signal - volumetric and mechanical efficiencies;

  • Input signal - volumetric and mechanical losses.

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

1e-3 MPa
Program usage name

p_threshold
Evaluatable

Yes

# Angular velocity threshold for motor-pump transition — threshold angular velocity for the transition mode
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

The threshold value of the angular velocity for switching between the operating modes of the pump and the hydraulic motor. The transition area is defined around 0 rpm between the positive and negative values of the threshold angular velocity. Within this area, the calculated leakage rate and friction moment are adjusted according to the transition term to ensure a smooth transition from one mode to another.

Dependencies

To use this parameter, set for Leakage and friction parameterization one of the values is:

  • Tabulated data - volumetric and mechanical efficiencies;

  • Input signal - volumetric and mechanical efficiencies;

  • Input signal - volumetric and mechanical losses.

Units

rad/s | deg/s | rad/min | deg/min | rpm | rps
Default value

100.0 rpm
Program usage name

w_threshold
Evaluatable

Yes

# Displacement threshold for motor-pump transition — the threshold value of the working volume for the transition mode
m^3/rad | mm^3/rad | cm^3/rad | km^3/rad | m^3/deg | cm^3/rev | m^3/rev | l/rad | l/rev | in^3/rad | ft^3/rad | gal/rad | igal/rad | in^3/deg | in^3/rev | gal/rev

Details

The threshold value of the working volume for switching between the operating modes of the pump and the hydraulic motor. The transition area is defined around 0 cm3/s between the positive and negative values of the threshold working volume. Within this area, the calculated leakage rate and friction moment are adjusted according to the transition term to ensure a smooth transition from one mode to another.

Units

m^3/rad | mm^3/rad | cm^3/rad | km^3/rad | m^3/deg | cm^3/rev | m^3/rev | l/rad | l/rev | in^3/rad | ft^3/rad | gal/rad | igal/rad | in^3/deg | in^3/rev | gal/rev
Default value

0.1 cm^3/rev
Program usage name

displacement_threshold
Evaluatable

Yes

# Cross-sectional area at ports A and B — cross-sectional area of ports A and B
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 holes in ports A and B. It is assumed that the areas are equal.

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

# Check if operating beyond the range of supplied tabulated data — a message about going beyond the limits of the provided data
None | Error

Details

Select a value Error to stop the simulation when the block uses values outside the provided data range.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization one of the values is:

  • Tabulated data - volumetric and mechanical efficiencies;

  • Tabulated data - volumetric and mechanical losses;

Values

None | Error
Default value

None
Program usage name

supplied_range_assert_action
Evaluatable

No

# Check if operating beyond motor mode — a message about the operation of the unit outside the hydraulic motor mode
None | Error

Details

Choose Error to stop the simulation when the unit is operating in forward or reverse pump modes.

Dependencies

To use this parameter, set for the parameter Leakage and friction parameterization meaning Input signal - volumetric and mechanical losses.

Values

None | Error
Default value

None
Program usage name

operating_mode_assert_action
Evaluatable

No