Double-Acting Actuator (TL)

Page in progress.

Double-acting linear actuator in a thermal liquid network.

double acting actuator tl

Description

Block Double-Acting Actuator (TL) simulates an actuator that converts the pressure drop between two chambers containing thermal liquid into piston movement. The movement of the piston is controlled by the pressure drop on both sides of the plate separating the chambers of the block. The limits of piston travel are modelled by one of the rigid stop models. The compressibility of the fluid is additionally modelled in both piston chambers.

The figure shows the main components of the actuator. Ports A and B represent the inlets for isothermal liquid. Port C is associated with the actuator body, port R is associated with the piston and returns the piston velocity. The piston position is calculated internally and transferred to port p.

The HA and HB ports are thermal interfaces between each chamber and the environment. The moving piston is adiabatic.

double acting actuator tl 1

Relocation

The piston displacement is determined by the displacement of port R relative to port C. The value of the Mechanical orientation parameters determines the direction of piston displacement. Piston displacement is neutral (equal to 0) when the volume of chamber A is equal to Dead volume in chamber A.

The direction of piston movement depends on the Mechanical orientation parameters. If the mechanical orientation is positive, the piston movement will be positive with respect to the actuator body when the gauge pressure at port A is positive. The direction of motion is reversed when the mechanical orientation is negative.

Rigid Restrictor Model

A set of rigid stops limits the range of motion of the piston. This block uses an implementation of the block Translational Hard Stop, in which the rigid stops are treated as spring-damping systems. The spring stiffness coefficient determines the restoring component of the contact force of the rigid stop and the damping coefficient determines the dissipating component.

The hard stops are located at the extreme ends of the piston stroke. If the mechanical orientation is positive, the lower hard stop is at , and the upper hard stop is at . If the mechanical orientation is negative, the lower hard stop is at , and the upper hard stop is at .

Damper

The block can simulate damping at the extreme positions of the piston. If Cylinder A end cushioning and/or Cylinder B end cushioning is checked, the block takes into account the deceleration of the piston as it approaches the maximum value of the piston stroke length as determined by the Piston stroke parameters. For more information on the hydraulic cylinder damper, refer to the block Cylinder Cushion (TL)

Friction

When Cylinder friction is checked, the block takes into account the friction of the piston as it moves, with the resulting friction being a combination of Stribeck, Coulomb and viscosity effects. The block measures the pressure difference between the pressure in the chamber and the ambient pressure. For more information on the friction model and its limitations, see the block Cylinder Cushion (TL).

Block diagram

Block Double-Acting Actuator (TL) consists of three blocks of the Thermal liquid library and two blocks of the Mechanics library:

The structure diagram of the actuator is shown in the schematic diagram.

double acting actuator tl 1

When the parameters Cylinder friction, Cylinder A end cushioning or Cylinder B end cushioning are checked, the block diagram also includes a block Cylinder Friction (TL) or two blocks Cylinder Cushion (TL).

double acting actuator tl 2

Ports

Conserving

# A — inlet for fluid flow into the chamber A
thermal liquid

Details

Thermal liquid port corresponding to the inlet to chamber A.

Program usage name

port_a

# B — inlet for fluid flow into the chamber B
thermal liquid

Details

Thermal liquid port corresponding to the inlet to chamber B.

Program usage name

port_b

# R — actuator piston
translational mechanics

Details

A mechanical progressive port corresponding to the actuator piston.

Program usage name

rod_flange

# C — drive housing
translational mechanics

Details

Mechanical progressive port corresponding to the actuator housing.

Program usage name

case_flange

# HA — heat flux through the chamber A
`heat

Details

Thermal non-directional port corresponding to chamber A.

Program usage name

thermal_port_a

# HB — heat flux through the chamber B
`heat

Details

Thermal non-directional port corresponding to chamber B.

Program usage name

thermal_port_b

Output

# p — piston position
scalar

Details

Piston position in m.

Data types	`Float64`.
Complex numbers support	No

Parameters

Actuator

# Same fluid on both sides — whether the same fluid is modelled in both chambers of the unit

Details

Whether the same fluid is modelled on both sides of the block. If the parameters are checked, the fluid properties are propagated through the block. If unchecked, the chambers in the block are connected to isolated networks of fluids with different properties.

Default value	`true (switched on)`
Program usage name	`same_properties`
Evaluatable	No

# Mechanical orientation — piston travel direction
Pressure at A causes positive displacement of R relative to C | Pressure at A causes negative displacement of R relative to C

Details

Defines the direction of piston movement. Options for selection:

Pressure at A causes positive displacement of R relative to C - the piston movement is positive if the volume of liquid in port A increases. This corresponds to the movement of the rod out of the cylinder.
Pressure at A causes negative displacement of R relative to C - The piston movement is negative if the volume of liquid in port A increases. This corresponds to the rod moving inside the cylinder.

Values	`Pressure at A causes positive displacement of R relative to C` \| `Pressure at A causes negative displacement of R relative to C`
Default value	`Pressure at A causes positive displacement of R relative to C`
Program usage name	`orientation`
Evaluatable	No

# Piston cross-sectional area in chamber A — cross-sectional area of the chamber piston rod A
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of the piston rod on the chamber side A.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.01 m^2`
Program usage name	`piston_area_a`
Evaluatable	Yes

# Piston cross-sectional area in chamber B — cross-sectional area of the chamber piston rod B
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of the piston rod on the chamber side B.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.01 m^2`
Program usage name	`piston_area_b`
Evaluatable	Yes

# Piston stroke — piston stroke
m | cm | ft | in | km | mi | mm | um | yd

Details

Maximum possible piston travel.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.1 m`
Program usage name	`stroke`
Evaluatable	Yes

# Dead volume in chamber A — volume of liquid in chamber A, at which piston movement is equal to 0
l | gal | igal | m^3 | cm^3 | ft^3 | in^3 | km^3 | mi^3 | mm^3 | um^3 | yd^3 | N*m/Pa | N*m/bar | lbf*ft/psi | ft*lbf/psi

Details

Volume of liquid in chamber A at piston movement value 0. This fluid volume corresponds to the position of the piston at which it is up against the actuator end cap.

Values	`l` \| `gal` \| `igal` \| `m^3` \| `cm^3` \| `ft^3` \| `in^3` \| `km^3` \| `mi^3` \| `mm^3` \| `um^3` \| `yd^3` \| `Nm/Pa` \| `Nm/bar` \| `lbfft/psi` \| `ftlbf/psi`
Default value	`1e-05 m^3`
Program usage name	`dead_volume_a`
Evaluatable	Yes

# Dead volume in chamber B — volume of liquid in the chamber B, at which the piston movement is equal to 0
l | gal | igal | m^3 | cm^3 | ft^3 | in^3 | km^3 | mi^3 | mm^3 | um^3 | yd^3 | N*m/Pa | N*m/bar | lbf*ft/psi | ft*lbf/psi

Details

Volume of liquid in chamber B at piston movement value `0'. This fluid volume corresponds to the position of the piston at which it is up against the actuator end cap.

Values	`l` \| `gal` \| `igal` \| `m^3` \| `cm^3` \| `ft^3` \| `in^3` \| `km^3` \| `mi^3` \| `mm^3` \| `um^3` \| `yd^3` \| `Nm/Pa` \| `Nm/bar` \| `lbfft/psi` \| `ftlbf/psi`
Default value	`1e-05 m^3`
Program usage name	`dead_volume_b`
Evaluatable	Yes

# Environment pressure specification — method of setting the ambient pressure
Atmospheric pressure | Specified pressure

Details

Method of setting the ambient pressure. Variant Atmospheric pressure sets the ambient pressure to 0.101325 MPa.

Values	`Atmospheric pressure` \| `Specified pressure`
Default value	`Atmospheric pressure`
Program usage name	`pressure_type`
Evaluatable	No

# Environment pressure — ambient pressure
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

User-defined ambient pressure.

Dependencies

To use this parameter, set the parameters to Environment pressure specification value Specified pressure.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.101325 MPa`
Program usage name	`p_specified`
Evaluatable	Yes

Hard Stop

# Hard stop model — selecting the model of the hard stop
Stiffness and damping applied smoothly through transition region, damped rebound | Full stiffness and damping applied at bounds, undamped rebound | Full stiffness and damping applied at bounds, damped rebound

Details

Selects the model for the force acting on the piston when it is at the end positions. See block for more information Translational Hard Stop

Values	`Stiffness and damping applied smoothly through transition region, damped rebound` \| `Full stiffness and damping applied at bounds, undamped rebound` \| `Full stiffness and damping applied at bounds, damped rebound`
Default value	`Stiffness and damping applied smoothly through transition region, damped rebound`
Program usage name	`hardstop_model`
Evaluatable	No

# Hard stop stiffness coefficient — stiffness factor
N/m | lbf/ft | lbf/in

Details

Piston stiffness coefficient.

Values	`N/m` \| `lbf/ft` \| `lbf/in`
Default value	`1e10 N/m`
Program usage name	`k_hard_stop`
Evaluatable	Yes

# Hard stop damping coefficient — damping factor
kg/s | N*s/m | N/(m/s) | lbf/(ft/s) | lbf/(in/s)

Details

Piston damping factor.

Values	`kg/s` \| `N*s/m` \| `N/(m/s)` \| `lbf/(ft/s)` \| `lbf/(in/s)`
Default value	`150.0 N*s/m`
Program usage name	`C_hard_stop`
Evaluatable	Yes

# Transition region — range of action of the rigid stop model
m | cm | ft | in | km | mi | mm | um | yd

Details

The operating range of the hard stop. Outside of this range, the piston end positions are not applied. Hard stop model is not applied and no additional force from the stop is applied to the piston.

Dependencies

To use this parameter, set parameter Hard stop model value Stiffness and damping applied smoothly through transition region, damped rebound.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.1 mm`
Program usage name	`transition_region`
Evaluatable	Yes

Cushion A

# Cylinder A end cushioning — option to simulate piston braking due to damper action

Details

Whether the deceleration of the piston at its extreme positions is taken into account. For more information, see the block see the block Cylinder Cushion (TL).

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

# Cushion plunger cross-sectional area — cross-sectional area of the damping plug
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of the damping plug.

Dependencies

To use this parameter, select the check box. Cylinder A end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.0001 m^2`
Program usage name	`plunger_area_a`
Evaluatable	Yes

# Cushion plunger length — damping plug length
m | cm | ft | in | km | mi | mm | um | yd

Details

Length of the damping plug.

Dependencies

To use this parameter, select the checkbox Cylinder A end cushioning.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.001 m`
Program usage name	`plunger_length_a`
Evaluatable	Yes

# Cushion orifice area — area of the opening between the damper chambers
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The area of the opening between the damper chambers.

Dependencies

To use this parameters, tick the checkbox Cylinder A end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-06 m^2`
Program usage name	`cushioning_valve_area_a`
Evaluatable	Yes

# Leakage area between plunger and cushion sleeve — clearance area between damper plug and bushing
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The clearance area between the damper plunger and the sleeve. Parameters maintains the computational stability of the simulation by ensuring flow continuity.

Dependencies

To use this parameter, select the checkbox Cylinder A end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-07 m^2`
Program usage name	`plunger_leakage_area_a`
Evaluatable	Yes

# Check valve cracking pressure differential — differential pressure at which the check valve starts to open
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

The pressure above which the damper actuates. When the pressure difference between port A and meets or exceeds this parameters value, the damper check valve will open.

Dependencies

To use this parameter, select the checkbox Cylinder A end cushioning.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.01 MPa`
Program usage name	`delta_p_crack_a`
Evaluatable	Yes

# Check valve maximum pressure differential — pressure drop required to fully open the check valve
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Maximum differential pressure of the damper check valve. This parameters sets the upper pressure limit to keep the system pressure realistic.

Dependencies

To use this parameters, select the check box. Cylinder A end cushioning.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.1 MPa`
Program usage name	`delta_p_max_a`
Evaluatable	Yes

# Check valve maximum area — area of fully open check valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area of the check valve orifice in the fully open position.

Dependencies

To use this parameter, select the check box. Cylinder A end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.0001 m^2`
Program usage name	`check_valve_max_area_a`
Evaluatable	Yes

# Check valve leakage area — leakage area with fully closed check valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Total possible leakage area with the check valve fully closed. Any area smaller than this value increases smoothly to the specified leakage area. This value contributes to computational stability by maintaining flow continuity.

Dependencies

To use this parameters, select the checkbox Cylinder A end cushioning.

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	`check_valve_leakage_area_a`
Evaluatable	Yes

# Smoothing factor — numerical smoothing factor

Details

Continuous smoothing factor that provides a smooth opening by correcting the valve characteristic in the nearly open and nearly closed positions. Set a non-zero value less than one to increase the stability of the simulation.

Dependencies

To use this parameters, check the checkbox. Cylinder A end cushioning.

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

Cushion B

# Cylinder B end cushioning — option to simulate piston braking due to damper action

Details

Whether the deceleration of the piston at its extreme positions is taken into account. For more information, see the block see the block Cylinder Cushion (TL).

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

# Cushion plunger cross-sectional area — cross-sectional area of the damping plug
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Cross-sectional area of the damping plug.

Dependencies

To use this parameter, select the check box. Cylinder B end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.0001 m^2`
Program usage name	`plunger_area_b`
Evaluatable	Yes

# Cushion plunger length — damping plug length
m | cm | ft | in | km | mi | mm | um | yd

Details

Length of the damping plug.

Dependencies

To use this parameter, select the checkbox Cylinder B end cushioning.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.001 m`
Program usage name	`plunger_length_b`
Evaluatable	Yes

# Cushion orifice area — area of the opening between the damper chambers
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The area of the opening between the damper chambers.

Dependencies

To use this parameters, tick the checkbox Cylinder B end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-06 m^2`
Program usage name	`cushioning_valve_area_b`
Evaluatable	Yes

# Leakage area between plunger and cushion sleeve — clearance area between damper plug and bushing
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The clearance area between the damper plunger and the sleeve. Parameters maintains the computational stability of the simulation by ensuring flow continuity.

Dependencies

To use this parameter, select the checkbox Cylinder B end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-07 m^2`
Program usage name	`plunger_leakage_area_b`
Evaluatable	Yes

# Check valve cracking pressure differential — differential pressure at which the check valve starts to open
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

The pressure above which the damper actuates. When the pressure difference between port B and meets or exceeds this parameter, the damper check valve will open.

Dependencies

To use this parameter, select the checkbox Cylinder B end cushioning.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.01 MPa`
Program usage name	`delta_p_crack_b`
Evaluatable	Yes

# Check valve maximum pressure differential — pressure drop required to fully open the check valve
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Maximum differential pressure of the damper check valve. This parameters sets the upper pressure limit to keep the system pressure realistic.

Dependencies

To use this parameters, select the check box. Cylinder B end cushioning.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.1 MPa`
Program usage name	`delta_p_max_b`
Evaluatable	Yes

# Check valve maximum area — area of fully open check valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area of the check valve orifice in the fully open position.

Dependencies

To use this parameter, select the check box. Cylinder B end cushioning.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.0001 m^2`
Program usage name	`check_valve_max_area_b`
Evaluatable	Yes

# Check valve leakage area — leakage area with fully closed check valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Dependencies

To use this parameters, select the checkbox Cylinder B end cushioning.

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	`check_valve_leakage_area_b`
Evaluatable	Yes

# Smoothing factor — numerical smoothing factor

Details

Dependencies

To use this parameters, check the checkbox. Cylinder B end cushioning.

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

Friction

# Cylinder friction — option for modelling friction during piston movement

Details

Whether the friction of the piston during movement is taken into account. The block friction force is made up of the Stribeck force, Coulomb force and viscosity. For more information, see block Cylinder Friction (TL).

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

# Breakaway to Coulomb friction force ratio — the ratio of the detachment force to the Coulomb friction force

Details

The ratio of the detachment force to the Coulomb friction force.

Dependencies

To use this parameter, tick the checkbox Cylinder friction.

Default value	`1.2`
Program usage name	`Coulomb_breakaway_ratio`
Evaluatable	Yes

# Breakaway friction velocity — friction threshold
fpm | fps | kph | mph | m/s | cm/s | ft/s | in/s | km/s | mi/s | mm/s

Details

The threshold value of velocity at which anti-friction motion begins.

Dependencies

To use this parameter, select the check box. Cylinder friction.

Values	`fpm` \| `fps` \| `kph` \| `mph` \| `m/s` \| `cm/s` \| `ft/s` \| `in/s` \| `km/s` \| `mi/s` \| `mm/s`
Default value	`0.1 m/s`
Program usage name	`v_breakaway`
Evaluatable	Yes

# Preload force — initial force in the cylinder during seal assembly, N
N | kN | lb | mN | dyn | lbf

Details

Initial force in the cylinder due to the seal assembly. The unit uses this parameter to calculate the Coulomb friction force.

Dependencies

To use this parameter, select the check box. Cylinder friction.

Values	`N` \| `kN` \| `lb` \| `mN` \| `dyn` \| `lbf`
Default value	`20.0 N`
Program usage name	`F_preload`
Evaluatable	Yes

# Coulomb friction force coefficient — Coulomb friction force coefficient
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2 | N/Pa

Details

Coulomb friction force coefficient.

Dependencies

To use this parameters, tick the checkbox Cylinder friction.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2` \| `N/Pa`
Default value	`1e-06 N/Pa`
Program usage name	`Coulomb_coefficient`
Evaluatable	Yes

# Viscous friction coefficient — viscous friction coefficient
kg/s | N*s/m | N/(m/s) | lbf/(ft/s) | lbf/(in/s)

Details

Coefficient of viscous friction.

Dependencies

To use this parameter, select the check box. Cylinder friction.

Values	`kg/s` \| `N*s/m` \| `N/(m/s)` \| `lbf/(ft/s)` \| `lbf/(in/s)`
Default value	`100.0 N*s/m`
Program usage name	`viscous_coefficient`
Evaluatable	Yes

Initial Conditions

# Initial piston displacement from chamber A cap — initial position of the piston relative to the chamber cover A
m | cm | ft | in | km | mi | mm | um | yd

Details

Piston position relative to the chamber lid A at the beginning of the simulation.

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

# Fluid dynamic compressibility — fluid compressibility modelling option

Details

Accounts for the change in density of the fluid due to its compressibility. If the checkbox is selected Fluid dynamic compressibility*is checked, changes due to the mass flow rate of the fluid in the block are calculated in addition to density changes due to pressure changes. In the *isothermal liquid library, all blocks calculate density as a function of pressure.

Default value	`true (switched on)`
Program usage name	`dynamic_compressibility`
Evaluatable	No

# Initial liquid pressure in chamber A — initial fluid pressure for compressible liquids in the chamber A
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Initial fluid pressure for compressible liquids in chamber A.

Dependencies

To use this parameter, select the checkbox Fluid dynamic compressibility.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.101325 MPa`
Program usage name	`p_start_a`
Evaluatable	Yes

# Initial liquid pressure in chamber B — initial fluid pressure for compressible liquids in the chamber B
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Initial fluid pressure for compressible liquids in chamber B.

Dependencies

To use this parameter, select the checkbox Fluid dynamic compressibility.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.101325 MPa`
Program usage name	`p_start_b`
Evaluatable	Yes

Details

Initial liquid temperature for compressible liquids in chamber A.

Dependencies

To use this parameter, select the checkbox Fluid dynamic compressibility.

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

Details

Initial liquid temperature for compressible liquids in chamber B.

Dependencies

To use this parameter, select the checkbox Fluid dynamic compressibility.

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

Double-Acting Actuator (TL)

Description

Relocation

Rigid Restrictor Model

Damper

Friction

Block diagram

Ports

Conserving

Output

Parameters

Actuator

Hard Stop

Cushion A

Cushion B

Friction

Initial Conditions

See also