Translational Mechanical Converter (IL)
The interface between isothermal liquid and mechanical translational networks.
blockType: AcausalFoundation.IsothermalLiquid.Elements.TranslationalMechanicalConverter
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Description
Block Translational Mechanical Converter (IL) It is an interface between an isothermal liquid network and a mechanical translational network. The unit converts fluid pressure into mechanical force and vice versa. It can be used as a base for translational drives.
The block icon changes depending on the value of the Mechanical orientation parameter.
The volume of liquid in the converter changes during operation. If the Fluid dynamic compressibility parameter is enabled, the pressure is calculated depending on the compressibility of the liquid (dynamic compressibility of the liquid).
The Mechanical orientation parameter determines whether an increase in fluid volume leads to a displacement of port R towards port C or in the opposite direction from it.
Port A is the isothermal fluid port corresponding to the input of the transducer. Ports R and C are mechanical translational ports corresponding to the stem and the body of the converter, respectively.
Conservation of mass
The mass conservation equations for the converter have the form:
where:
-
— mass flow through port A.
-
— mechanical orientation of the converter (
1if an increase in fluid pressure causes a positive displacement of R relative to C,−1if an increase in fluid pressure causes a negative displacement of R relative to C). -
— the density of the liquid inside the transducer.
-
— the volumetric modulus of elasticity of the liquid in the transducer.
-
— the cross-sectional area of the hydraulic part of the converter.
-
— linear speed of the mechanical part of the converter.
-
and — linear speeds of ports R and C, respectively.
-
— movement of the mechanical part of the converter.
-
— the volume of liquid inside the converter.
-
— the volume of liquid at which the position of the stem is equal to
0. -
— pressure inside the transducer.
The position of the stem is zero when the volume of the liquid is . Depending on the value of the parameter Mechanical orientation:
-
If the Mechanical orientation parameter is set to
Pressure at A causes positive displacement of R relative to C, the displacement of the stem increases when the volume of the liquid increases compared to . -
If the Mechanical orientation parameter is set to
Pressure at A causes negative displacement of R relative to C, the displacement of the stem decreases when the volume of the liquid increases compared to .
The equations used to calculate the density and modulus of bulk elasticity of a mixture of liquids depend on the chosen model of the isothermal fluid.
Assumptions and limitations
-
The walls of the transducer are ideally rigid.
-
The converter does not contain any mechanical rigid limiters. To turn on the hard limiters, use the block Translational Hard Stop.
-
The flow resistance between the input and the inside of the converter is negligible.
-
The kinetic energy of the liquid in the converter is negligible.
Ports
Non-directional
A — inlet of the pass converter:q[<br>] isothermal liquid
The isothermal fluid port corresponds to the input of the converter.
R — stock
translational mechanics
Mechanical translational port, corresponds to the converter rod.
C — housing
translational mechanics
Mechanical translational port, corresponds to the converter housing.
Parameters
Mechanical orientation — orientation of the pass converter:q[<br>] Pressure at A causes positive displacement of R relative to C (default) | Pressure at A causes negative displacement of R relative
Sets the direction of movement of the rod relative to the liquid pressure:
-
Pressure at A causes positive displacement of R relative to C— an increase in liquid pressure leads to a positive displacement of port R relative to port C. -
Pressure at A causes negative displacement of R relative to C— an increase in fluid pressure leads to a negative displacement of R relative to port C.
Initial interface displacement — the initial offset of port R relative to port C
0 (default)
Linear displacement of port R relative to port C at the beginning of the simulation, m. Value 0 corresponds to the initial volume of the liquid equal to Dead volume.
Dependencies
-
If Mechanical orientation is important
Pressure at A causes positive displacement of R relative to C, the parameter value must be greater than or equal to0. -
If Mechanical orientation is important
Pressure at A causes negative displacement of R relative to C, the parameter value must be less than or equal to0.
Interface cross-sectional area — the area on which the liquid exerts pressure to create a force
0.01 m2 (default)
The area over which the liquid exerts pressure to create force.
Dead volume — the volume of liquid at which the position of the stem is equal to 0
1e−5 m3 (default)
The volume of liquid at which the position of the stem is equal to 0.
Environment pressure specification — method for setting ambient pressure
Atmospheric pressure (by default) | Specified pressure
Defines the method of setting the ambient pressure:
-
Atmospheric pressure— use atmospheric pressure. -
Specified pressure— the pressure value specified in the Environment pressure parameter.
Environment pressure — pressure outside the pass converter:q[<br>] 101325 Pa (default)
The pressure outside the transducer acting against the pressure inside. Meaning 0 This means that the converter operates in a vacuum.
Dependencies
Used if the Environment pressure specification parameter is set to Specified pressure.
Fluid dynamic compressibility — determines whether it is necessary to simulate the dynamic compressibility of a liquid
Enabled (by default) | Disabled
Specifies whether the dynamic compressibility of the liquid should be taken into account. Dynamic compressibility makes the density of a liquid dependent on pressure, which affects the transient response of the system on small time scales.
Initial liquid pressure — liquid pressure at zero time
101325 Pa (default)
The pressure of the liquid at the beginning of the simulation.
Dependencies
Used if the Fluid dynamic compressibility parameter is set to Enabled.