13.4.2 Module Related Variables
The module variables refer to those Expression Editor variables pertaining to the core Simerics-MP modules. These are categorized as:
- Dependent / Independent Variables - Primary, Property and Derived variables pertaining to a given module
- Integrated Quantities - Module quantities integrated over a volume or boundary
Each module has variables and integrated quantities associated with it. The specific variable names available for a given module are listed in Module Related Expressions.
The expression module[.subname].exists is used to check if a module exists in current project.
Example
Example 10 :
disp = trans_1D_1CV.displacement
pre = flow.P
temp = (heat.exists?) heat.T : 300
Dependent/Independent variables
The Dependent and Independent variables: (Primary, Property and Derived) for a given module are available for access and use in expressions throughout Simerics-MP when the respective module is activated. These dependent and independent variables correspond to arrays with values at every cell in the solution domain.
The general format for using a Primary, Property and Derived Variable in the Expression Editor is: module[.subname].var
- The Dependent and Independent Variables available for the Expression Editor correspond to the list of Variables in the Results Panel, although the specific variable vames may be different.
- The specific Variable Names available for a given module are discussed in Module Variables.
- Alternatively, the Variable Names for the Primary, Property and Derived Variables available for expressions can be found in the filename_points.txt file. By running the code with a Point Probe activated, the User can generate this file to determine the probable name for a given variable in the code.
- There are Variable Names in addition to those in the points.txt file that can be used in expressions. (For example, the Flow module variable Velocity Vector V is not listed in the points.txt file, but can be used in an Expression, as flow.V).
- If a variable name is incorrect or not available it will generate an error message when trying to save see, Figure 13.17 and Figure 13.18 (i.e. clicking on the OK button).
- Dependent variables in the form of Derived Variables can also be created for use in Expression Editor using the Display Variable Function . An example of the use of a Derived Variable in the Expression Editor is provided below:
Figure 13.19 - Dependent Variables
Common Module
Description
The Common module is the shared module in Simerics-MP. It follows a different convention than the other modules, in that “share” is used in place of “common” as the module_name, such that share.var_name is used instead of common.var_name. Alternatively, the name “share” can be let out entirely such that share.var_name reduces to simply name.
share.density or share.rho: density [kg/m3]
share.porosity or share.por: porosity [ ]
share.cells_vol: cell volume [m3]
Flow module
Description
flow.pressure or flow.P: pressure [Pa]
flow.V: (vector) velocity [m/s]
flow.u/flow.v/flow.w: cartesian velocity components [m/s]
flow.viscosity or flow.mu: laminar dynamic viscosity [Pa-s]
flow.totalP: total pressure [Pa]
flow.vMag: velocity magnitude [m/s]
flow.labVr/flow.labVt/flow.labVa: velocity components in radial/ tangential/axial direction [m/s]
flow.relVr/flow.relVt/flow.relVa: relative velocity components in radial/ tangential/axial direction [m/s]
flow.relVelocity: (vector) relative velocity [m/s]
flow.vrMag: relative velocity magnitude [m/s]
flow.vorticity: (vector) vorticity [1/s]
flow.vorticityMag: vorticity magnitude [1/s]
flow.mach: Mach number [ ]
flow.sspd: speed of sound [m/s]
Cavitation module
Description
cavitation.Fgas: free gas mass fraction [ ]
cavitation.Fvap: vapor mass fraction [ ]
cavitation.Dgas: dissolved gas mass fraction [ ]
cavitation.volFracGas: free gas volume fraction [ ]
cavitation.volFracVap: vapor volume fraction [ ]
cavitation.volFracDGas: dissolved gas volume fraction [ ]
cavitation.volFracT: total gas phase volume fraction [ ]
cavitation.damagePower: cavitation damage power [W]
Turbulence module
Description
turbulence.tke: turbulent kinetic energy [m2/s2]
turbulence.ted: turbulent kinetic energy dissipation rate [m2/s3]
turbulence.muT: turbulent viscosity [Pa-s]
Heat module
Description
heat.temperatureor heat.T: temperature [K]
heat.conductivityor heat.K: heat conductivity [W/m-K]
heat.capacityor heat.C: heat capacity [J/kg-K]
heat.Ht: total enthalpy [J/kg]
heat.Et: total internal energy [J/kg]
heat.Tt: total temperature [K]
Species module
Description
species[.subname].concentraction or species.[subname].C: concentration [ ]
species.[subname].D: diffusivity [m2/s]
Multicomponent module
Description
component[.subname].C: component concentration [ ]
component[.subname].D: component diffusivity [m2/s]
component[.subname].soretDiff : Soret diffusivity [m2/s]
flowcomp[.subname].viscosity : component viscosity [Pa -s]
heatcomp[.subname].K : heat conductivity [W/m -K]
heatcomp[.subname].C : component heat capacity [J/kg]
sharecomp[.subname].rho : component density [kg/m3]
| ´ | Note: This section applies to the Multicomponent module Component variables only, not Mixture variables. The later are accessed via their parent module. For example, the viscosity of the mixture would be accessed via the Flow module as Mixture_Viscosity = flow.mu. |
Multiphase module
Description
phasecomp[.subname].vFrac: component volume fraction [ ]
flowphasecomp[.subname].viscosity: component viscosity [Pa-s]
heatphasecomp[.subname].K : component heat conductivity [W/m-K]
heatphasecomp[.subname].C: component heat capacity [J/kg-K]
sharephasecomp[.subname].rho: component density [kg/m3]
|
Note: This section applies to the Multiphase module Component variables only, not Mixture Variables. The later are accessed as via their parent module. For example, the viscosity of the mixture would be accessed via the Flow module as Mixture_Viscosity = flow.mu. |
Examples
air_visc = flowphasecomp.air.viscosity
Dynamics module
Description
Dynamics Translation module
trans_1d[.subname].displacement: displacement [m]
trans_1d[.subname].velocity: velocity [m/s]
trans_1d[.subname].accelaration: accelaration [m/s2]
trans_1d[.subname].force: force [N]
Dynamics Rotation module
rotate_1d[.subname].angle: angle [rad]
rotate_1d[.subname].omega: angular velocity [rad/s]
rotate_1d[.subname].rpm: rotational speed in revolution per minute [rpm]
rotate_1d[.subname].torque: torque [N-m]
rotate_1d[.subname].accelaration: angular accelaration [rad/s2]
Advanced Variables in Dynamics module
The following variables are ODE solutions before application of constraints, and corrections based on constraints. They can be used with more complicated constraints such as 2-dimensional motion inside a circle.
trans_1d[.subname].ode_displacement: initial ODE solution for displacement [m]
trans_1d[.subname].ode_velocity: initial ODE solution for velocity [m/s]
rotate_1d[.subname].ode_displacement: initial ODE solution for angular displacement [rad]
rotate_1d[.subname].ode_velocity: initial ODE solution for angular velocity [rad/s]
Examples
dy = trans_1d.Y.ode_displacement
domega = rotate_1d.Y.ode_velocity
Compartment module
Description
valve_type[.subname].displacement: for Spool Valve, use name "spool_valve". [m]
Examples
disp = spool_valve.displacement
Stress module
Description
stress[.subname].Disp: (vector)displacement [m]
stress[.subname].dx: displacement component [m]
stress[.subname].dy: displacement component [m]
stress[.subname].dz: displacement component [m]
stress[.subname].E: Young's modulus [Pa]
stress[.subname].nu: Poisson's ratio [ ]
stress[.subname].alpha: thermal expansion coefficient [ ]
stress[.subname].disp_mag: displacement magnitude [m]
stress[.subname].stress_inv: stress invariant [Pa]
Pump module
Description
pump_type[.subname].angle: pump accumulated rotation angle [rad]
pump_type[.subname].omega: pump rotation speed [rad]
pump_type[.subname].rpm: pump rotation speed in rpm [rpm]
Example
pumpspeed = gerotor.rpm
Integrated Quantities
These quantities correspond to the list of output variables available for activation and to display in X-Y Plots on the Plot Panel. These quantities are stored in the filename_integral.txt file, although the specific Variable Names are typically different. Integrated Quantities pertaining to a given module are available for access and use in expressions throughout Simerics-MP/Simerics-MP+ when the respective module is activated.
Format for Integrated Variables:
When patch and volume names have no conflict:
module[.subname].variable@patch_name
module[.subname].variable@volume_name
When patch and volume or variable names have conflicts :
module[.subname].variable@patch.patch_name
module[.subname].variable@volume.volume_name
|
Note: The variables are integral values on a boundary or volume. Mostly, the name of variable is the same as in "integral.txt" file except without the suffix "_". |
Examples
- Power is written in integral.txt as "pow_", whereas in expressions, variable for power is "pow".
To access power on a boundary named "rotor" we use:
- rotor_power = flow.pow@patch.rotor #if there is a volume named “rotor”
- rotor_power = flow.pow@rotor #if there is a volume named “rotor"
- Enthalpy is written in integral.txt as "h_", and in the “pipe” volume the enthalpy is accessed using the expression:
- enthalpy_pipe = heat.h@volume.pipe #if there is a boundary named “pipe”
- enthalpy_pipe = heat.h@pipe #if there is no boundary named “pipe”
- The integrated quantities available for every given module are listed under output variables for the respective module. The syntax to access the integrated quantities using the Expression Editor are given in the Expressions column in the respective modules below:
- Alternatively, the variable names for the integrated quantities available for expressions can be found in the filename_integrals.txt file. See Figure 13.20 and are discussed in Module Related Expressions.
- There are integral Variable Names in addition to those in the integrals.txt file that can be used in expressions. Go to links for module variables as explained above for a list of all variables available for a given module.
- Integrated Quantities at a Boundary or Volume can also be created. (See Integration and Averaging).
- If a Variable Name is incorrect or not available, the Expression Editor will generate an error message when trying to save (i.e. Click OK button).
Figure 13.20 - Variables in "integrals.txt"