Double-Acting Actuator (G-IL)

Linear actuator with chambers for isothermal liquid and gas.

blockType: EngeeFluids.IsothermalLiquid.Actuators.TranslationalDoubleActingWithGasChamber

Path in the library:

/Physical Modeling/Fluids/Isothermal Liquid/Actuators/Double-Acting Actuator (G-IL)

Description

Block Double-Acting Actuator (G-IL) It consists of a chamber for an isothermal liquid and a chamber for a gas, separated by a piston plate. The piston is actuated by the pressure difference between the chambers. The movement of the piston in a position close to full extension or full retraction is limited to one of the four stop patterns.

Port A is designed for isothermal liquid intake, and port B is designed for gas intake. The heat transfer elements between the gas chamber and the environment are connected to the H port. Port C is used for mechanical translational movement of the drive housing. The R port is connected to the drive piston. The position of the piston is determined by the port p.

double acting actuator g il 1

Offset

The displacement of the piston is measured as the position in port R relative to port C. Parameter Mechanical orientation determines the direction of displacement of the piston. The displacement of the piston is zero when the volume of the chamber is equal to the dead volume of the chamber. When you receive an offset as an input signal, make sure that the derivative of the position is equal to the piston velocity.

The stop model

To avoid mechanical damage to the piston when it is fully extended or retracted, the actuator usually exhibits non-linear behavior when the piston approaches these limits. Block Double-Acting Actuator (G-IL) simulates this behavior using four stop models that simulate the ductility of the material through a spring-damping system. Stop models:

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;
Based on coefficient of restitution.

The thrust force is modeled when the piston is at the upper or lower limit. The boundary region is located in the transition region (parameter Transition region) stroke of the piston (parameter Piston stroke) or the initial displacement of the piston. Outside of this area .

For more information about these settings, see the block page. Translational Hard Stop.

Block diagram

Block Double-Acting Actuator (G-IL) It consists of four library blocks Fundamental:

double acting actuator g il en

Ports

Output

# p — piston position, m
scalar

Details

A directional port associated with the position of the piston.

Data types	`Float64`
Complex numbers support	I don’t

Conserving

# H — heat flow
heat

Details

A non-directional port associated with the transfer of heat to or from the gas chamber.

Program usage name

thermal_port

# C — drive housing
translational mechanics

Details

A non-directional port connected to the case.

Program usage name

case_flange

# A — Entrance to chamber A
Isothermal liquid

Details

A non-directional port for isothermal liquid connected to the entrance to chamber A.

Program usage name

isothermal_liquid_port

# R — drive piston rod
translational mechanics

Details

A non-directional port connected to the piston rod.

Program usage name

rod_flange

# B — Entrance to chamber B
gas

Details

A non-directional gas port connected to the entrance to chamber B.

Program usage name

gas_port

Parameters

Configuration

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

Details

The direction of displacement of the piston. Pressure at A causes positive displacement of R relative to C corresponds to the piston extension when the pressure difference between chambers A and B is positive. Pressure at A causes negative displacement of R relative to C corresponds to the retraction of the piston when the pressure difference between chambers A and B is positive.

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	Yes

# Piston stroke — maximum stroke of the piston
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The maximum stroke of the piston.

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

# Initial piston displacement from chamber A cap — the position of the piston at the beginning of the simulation
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The position of the piston at the beginning of the simulation.

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

# Hard stop model — choosing a stop model
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 | Based on coefficient of restitution

Details

Selecting the model of the force acting on the piston when fully extended or fully retracted. For more information, see the block page 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` \| `Based on coefficient of restitution`
Default value	`Stiffness and damping applied smoothly through transition region, damped rebound`
Program usage name	`hardstop_model`
Evaluatable	Yes

# Hard-stop stiffness coefficient — stiffness coefficient
N/m | mN/m | kN/m | MN/m | GN/m | kgf/m | lbf/ft | lbf/in

Details

The coefficient of piston stiffness.

Dependencies

To use this parameter, set for the parameter Hard stop model one of the following 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.

Units	`N/m` \| `mN/m` \| `kN/m` \| `MN/m` \| `GN/m` \| `kgf/m` \| `lbf/ft` \| `lbf/in`
Default value	`1.0e10 N/m`
Program usage name	`k_hard_stop`
Evaluatable	Yes

# Hard-stop damping coefficient — damping coefficient
N*s/m | kgf*s/m | lbf*s/ft | lbf*s/in

Details

Piston damping coefficient.

Dependencies

To use this parameter, set for the parameter Hard stop model one of the following 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.

Units	`Ns/m` \| `kgfs/m` \| `lbfs/ft` \| `lbfs/in`
Default value	`150.0 N*s/m`
Program usage name	`C_hard_stop`
Evaluatable	Yes

# Transition region — the field of application of the thrust force model
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The range of application of the force model in the stop. Outside of this range of maximum extension and maximum retraction of the piston, the parameter Hard stop model it is not applied, and the piston is not affected by additional force.

Dependencies

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

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

# Coefficient of restitution — the ratio of the final and initial relative velocity between the slider and the stop after the collision

Details

The ratio of the final and initial relative velocity between the slider and the stop after the slider rebounds.

Dependencies

To use this parameter, set for the parameter Hard stop model meaning Based on coefficient of restitution.

Default value	`0.7`
Program usage name	`restitution_coefficient`
Evaluatable	Yes

# Static contact speed threshold — the threshold value of the relative velocity between the slider and the stop before the collision
m/s | mm/s | cm/s | km/s | m/hr | km/hr | in/s | ft/s | mi/s | ft/min | mi/hr | kn

Details

The threshold value of the relative velocity between the slider and the stop before the collision. When the slider hits the housing at a speed lower than the parameter value Static contact speed threshold they stay in contact. Otherwise, the slider will bounce. To avoid simulating static contact between the slider and the housing, set this parameter to 0.

Dependencies

To use this parameter, set for the parameter Hard stop model meaning Based on coefficient of restitution.

Units	`m/s` \| `mm/s` \| `cm/s` \| `km/s` \| `m/hr` \| `km/hr` \| `in/s` \| `ft/s` \| `mi/s` \| `ft/min` \| `mi/hr` \| `kn`
Default value	`0.001 m/s`
Program usage name	`v_static_contact_threshold`
Evaluatable	Yes

# Static contact release force threshold — the threshold value of the force required to switch from contact mode to free mode
N | nN | uN | mN | kN | MN | GN | dyn | lbf | kgf

Details

The minimum force required to exit the slider from static contact mode.

Dependencies

To use this parameter, set for the parameter Hard stop model meaning Based on coefficient of restitution.

Units	`N` \| `nN` \| `uN` \| `mN` \| `kN` \| `MN` \| `GN` \| `dyn` \| `lbf` \| `kgf`
Default value	`0.001 N`
Program usage name	`F_static_contact_release_threshold`
Evaluatable	Yes

Isothermal Liquid Side

# Piston cross-sectional area in chamber A — the cross-sectional area of the piston rod
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 piston rod in chamber A.

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	`piston_area_isothermal_liquid`
Evaluatable	Yes

# Dead volume in chamber A — the volume of the chamber when the piston is fully retracted
m^3 | um^3 | mm^3 | cm^3 | km^3 | ml | l | gal | igal | in^3 | ft^3 | yd^3 | mi^3

Details

An open volume in the liquid chamber when the piston is fully retracted.

Units	`m^3` \| `um^3` \| `mm^3` \| `cm^3` \| `km^3` \| `ml` \| `l` \| `gal` \| `igal` \| `in^3` \| `ft^3` \| `yd^3` \| `mi^3`
Default value	`1.0e-5 m^3`
Program usage name	`dead_volume_isothermal_liquid`
Evaluatable	Yes

# Fluid dynamic compressibility — should I simulate the compressibility of a liquid

Details

Whether to simulate a change in the density of a liquid due to the compressibility of a liquid. If next to the parameter Fluid dynamic compressibility If the box is checked, then the changes caused by the mass flow in the unit are calculated in addition to the density changes caused by the pressure change. In the library Isothermal Liquid all blocks calculate density as a function of pressure.

Default value	`true (switched on)`
Program usage name	`dynamic_compressibility`
Evaluatable	Yes

# Initial liquid pressure in chamber A — initial fluid pressure for compressible fluids
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 initial fluid pressure for compressible fluids.

Dependencies

To use this option, check the box next to the option Fluid dynamic compressibility.

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_isothermal_liquid_start`
Evaluatable	Yes

# Environment pressure specification — reference ambient pressure
Atmospheric pressure | Specified pressure

Details

Reference ambient pressure. Meaning Atmospheric pressure sets the ambient pressure equal to 0.101325 MPa.

Values	`Atmospheric pressure` \| `Specified pressure`
Default value	`Atmospheric pressure`
Program usage name	`pressure_type_isothermal_liquid`
Evaluatable	Yes

# Environment pressure — user-defined ambient pressure
Pa | uPa | hPa | kPa | MPa | GPa | kgf/m^2 | kgf/cm^2 | kgf/mm^2 | mbar | bar | kbar | atm | ksi | psi | mmHg | inHg

Details

User-defined ambient pressure.

Dependencies

To use this parameter, set for the parameter Environment pressure specification meaning Specified pressure.

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_isothermal_liquid_specified`
Evaluatable	Yes

Gas Side

# Piston cross-sectional area in chamber B — the cross-sectional area of the piston rod
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 piston rod in chamber B.

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	`piston_area_gas`
Evaluatable	Yes

# Cross-sectional area at port B — port cross-sectional 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 port B.

Units	`m^2` \| `um^2` \| `mm^2` \| `cm^2` \| `km^2` \| `in^2` \| `ft^2` \| `yd^2` \| `mi^2` \| `ha` \| `ac`
Default value	`0.001 m^2`
Program usage name	`gas_port_area`
Evaluatable	Yes

# Dead volume in chamber B — the volume of the chamber when the piston is fully retracted
m^3 | um^3 | mm^3 | cm^3 | km^3 | ml | l | gal | igal | in^3 | ft^3 | yd^3 | mi^3

Details

An open volume in the gas chamber when the piston is fully retracted.

Units	`m^3` \| `um^3` \| `mm^3` \| `cm^3` \| `km^3` \| `ml` \| `l` \| `gal` \| `igal` \| `in^3` \| `ft^3` \| `yd^3` \| `mi^3`
Default value	`1.0e-5 m^3`
Program usage name	`dead_volume_gas`
Evaluatable	Yes

# Initial gas pressure in chamber B — initial gas pressure in the chamber
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 initial pressure of the gas in the chamber.

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_gas_start`
Evaluatable	Yes

Details

The initial temperature in the gas chamber.

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

# Environment pressure specification — reference ambient pressure
Atmospheric pressure | Specified pressure

Details

Reference ambient pressure. Meaning Atmospheric pressure sets the ambient pressure equal to 0.101325 MPa.

Values	`Atmospheric pressure` \| `Specified pressure`
Default value	`Atmospheric pressure`
Program usage name	`pressure_type_gas`
Evaluatable	Yes

Details

User-defined ambient pressure.

Dependencies

To use this parameter, set for the parameter Environment pressure specification meaning Specified pressure.

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_gas_specified`
Evaluatable	Yes