Variable Naming Conventions

While it is possible to set up the same OpenMDAO multiphysics problem with different sets of variable names, it is preferable for codes solving the same physics to use the same variable names to be more easily interchangeable. This table provides the required names for coupling variables associated with a particular physics in MPhys.

The variable naming convention is defined as a Nested Classes with static variables. The names are access from the MPhysVariables class. If defining an component that uses the MPhys variable names repeatedly, it is often uses to define a local copy due to the long names that the nested variable classes.

import openmdao.api as om
from mphys import MPhysVariables

X_AERO0 = MPhysVariables.Aerodynamics.Surface.COORDINATES_INITIAL
U_AERO = MPhysVariables.Aerodynamics.Surface.DISPLACEMENTS
F_AERO = MPhysVariables.Aerodynamics.Surface.LOADS

class AeroSolver(om.ImplicitComponent):
    def setup(self):
        self.add_input(X_AERO0, shape=5, distributed=True, tags=['mphys_coordinates'])
        self.add_input(U_AERO0, shape=5, distributed=True, tags=['mphys_coupling'])
        self.add_output(F_AERO0, shape=3, distributed=True, tags=['mphys_coupling'])

Code Access	Associated Solver	MPhys tag	Variable description
MPhysVariables.Aerodynamics.Surface.Mesh.COORDINATES	Aerodynamic	mphys_coordinates	Aerodynamic surface coordinates from initial mesh file
MPhysVariables.Aerodynamics.Surface.Geometry.COORDINATES_INPUT	Aerodynamic	mphys_coordinates	Aerodynamic surface coordinates (initial coordinates)
MPhysVariables.Aerodynamics.Surface.Geometry.COORDINATES_OUTPUT	Aerodynamic	mphys_coordinates	Aerodynamic surface coordinates (geometry-deform jig shape)
MPhysVariables.Aerodynamics.Surface.COORDINATES_INITIAL	Aerodynamic	mphys_coordinates	Aerodynamic surface coordinates (jig shape)
MPhysVariables.Aerodynamics.Surface.COORDINATES_DEFORMED	Aerodynamic	mphys_coupling	Aerodynamic surface coordinates (deformed)
MPhysVariables.Aerodynamics.Surface.DISPLACEMENTS	Aerodynamic	mphys_coupling	Aerodynamic surface displacements
MPhysVariables.Aerodynamics.Surface.LOADS	Aerodynamic	mphys_coupling	Aerodynamic surface forces
MPhysVariables.Aerodynamics.Surface.TEMPERATURE	Aerodynamic	mphys_coupling	Temperature for convective solver at interface
MPhysVariables.Aerodynamics.Surface.HEAT_FLOW	Aerodynamic	mphys_coupling	Convective heat flow at interface
MPhysVariables.Structures.Mesh.COORDINATES	Structural	mphys_coordinates	Structural coordinates from initial mesh file
MPhysVariables.Structures.Geometry.COORDINATES_INPUT	Structural	mphys_coordinates	Structural coordinates (initial coordinates)
MPhysVariables.Structures.Geometry.COORDINATES_OUTPUT	Structural	mphys_coordinates	Structural coordinates (geometry-deformed jig shape)
MPhysVariables.Structures.COORDINATES	Structural	mphys_coordinates	Structural coordinates (jig shape)
MPhysVariables.Structures.DISPLACEMENTS	Structural	mphys_coupling	Structural state vector (displacements)
MPhysVariables.Structures.LOADS.AERODYNAMIC	Structural	mphys_coupling	Structural forces due to aerodynamics
MPhysVariables.Thermal.Mesh.COORDINATES	Thermal	mphys_coupling	Thermal coordinates from initial mesh file
MPhysVariables.Thermal.Geometry.COORDINATES_INPUT	Thermal	mphys_coupling	Thermal coordinates (initial coordinates)
MPhysVariables.Thermal.Geometry.COORDINATES_OUTPUT	Thermal	mphys_coupling	Thermal coordinates (geometry-deformed jig shape)
MPhysVariables.Thermal.COORDINATES	Thermal	mphys_coupling	Thermal coordinates (jig shape)
MPhysVariables.Thermal.TEMPERATURE	Thermal	mphys_coupling	Temperature at interface (thermal solver side)
MPhysVariables.Thermal.HeatFlow.AERODYNAMIC	Thermal	mphys_coupling	heat flow at interface due to aerodynamics (thermal solver side)

To make swapping solvers easier, it is also helpful to share noncoupling variable names if possible:

Variable	Associated Solver	MPhys tag	Variable description
MPhysVariables.Aerodynamics.FlowConditions.ANGLE_OF_ATTACK	Aerodynamic	mphys_input	Angle of attack (please include units=’deg’ or ‘rad’ when declared)
MPhysVariables.Aerodynamics.FlowConditions.YAW_ANGLE	Aerodynamic	mphys_input	Yaw angle (please include units=’deg’ or ‘rad’ when declared)
MPhysVariables.Aerodynamics.FlowConditions.MACH_NUMBER	Aerodynamic	mphys_input	Reference Mach number
MPhysVariables.Aerodynamics.FlowConditions.REYNOLDS_NUMBER	Aerodynamic	mphys_input	Reference Reynolds number
MPhysVariables.Aerodynamics.FlowConditions.DYNAMIC_PRESSURE	Aerodynamic	mphys_input	Dynamic pressure