FEM EquationFlux: Difference between revisions

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|Workbenches=[[FEM_Workbench|FEM]]
|Workbenches=[[FEM_Workbench|FEM]]
|Version=0.19
|Version=0.19
|SeeAlso=[[FEM_tutorial|FEM tutorial]]
|SeeAlso=
}}
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==Description== <!--T:8-->


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This equation is used to calculate the fluxes resulting usually from Poisson kind of equations. These include the [[Image:FEM_EquationHeat.svg|24px]] [[FEM_EquationHeat|Heat equation]] and the [[Image:FEM_EquationElectrostatic.svg|24px]] [[FEM_EquationElectrostatic|Electrostatic equation]].
ToDo

For info about the math of the equation, see the [http://www.elmerfem.org/blog/documentation/ Elmer models manual], section ''Flux Computation''.

==Usage==

# After adding an Elmer solver as described [[FEM_SolverElmer#Equations|here]], select it in the [[Tree_view|tree view]].
# Either use the toolbar button [[Image:FEM_EquationFlux.svg|24px]] or the menu {{MenuCommand|Solve → Flux equation}}.
# Now either add a heat equation (toolbar button [[Image:FEM_EquationHeat.svg|24px]] or menu {{MenuCommand|Solve → heat equation}}) or an electrostatic equation (toolbar button [[Image:FEM_EquationElectrostatic.svg|24px]] or menu {{MenuCommand|Solve → Electrostatic equation}}). This is important because the flux equation needs the constraints set for these equastions.
# When using the electrostatic equation, change the property {{PropertyData|Flux Coefficient}} to ''None''. and the property {{PropertyData|Flux Variable}} to ''Potential''.
# Change the [[#Solver_Settings|equation's solver settings]] or the [[FEM_SolverElmer_SolverSettings|general solver settings]] if necessary.

==Solver Settings==

For the general solver settings, see the [[FEM_SolverElmer_SolverSettings|Elmer solver settings]].

The flux equation provides these special settings:

==Constraint Information==

The flux equation does not have own constraints. It takes the constraints from the [[Image:FEM_EquationHeat.svg|24px]] [[FEM_EquationHeat|Heat equation]] or the [[Image:FEM_EquationElectrostatic.svg|24px]] [[FEM_EquationElectrostatic|Electrostatic equation]].

==Results==


The available results depend on the [[#Solver_Settings|solver settings]]. If none of them was set to ''true'', nothing is calculated. Otherwise also the corresponding results will be available.
==Usage== <!--T:9-->


The resulting flux is either the heat flux <math>\rm W/m^2</math> (misleadingly named "temperature flux") or the potential flux in <math>\rm W/m^2</math> (<math>\rm A\cdot V/m^2</math>).
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Revision as of 17:10, 16 August 2022

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FEM EquationFlux

Menu location
Solve → Flux equation
Workbenches
FEM
Default shortcut
None
Introduced in version
0.19
See also
None

This equation is used to calculate the fluxes resulting usually from Poisson kind of equations. These include the Heat equation and the Electrostatic equation.

For info about the math of the equation, see the Elmer models manual, section Flux Computation.

Usage

  1. After adding an Elmer solver as described here, select it in the tree view.
  2. Either use the toolbar button or the menu Solve → Flux equation.
  3. Now either add a heat equation (toolbar button or menu Solve → heat equation) or an electrostatic equation (toolbar button or menu Solve → Electrostatic equation). This is important because the flux equation needs the constraints set for these equastions.
  4. When using the electrostatic equation, change the property DataFlux Coefficient to None. and the property DataFlux Variable to Potential.
  5. Change the equation's solver settings or the general solver settings if necessary.

Solver Settings

For the general solver settings, see the Elmer solver settings.

The flux equation provides these special settings:

Constraint Information

The flux equation does not have own constraints. It takes the constraints from the Heat equation or the Electrostatic equation.

Results

The available results depend on the solver settings. If none of them was set to true, nothing is calculated. Otherwise also the corresponding results will be available.

The resulting flux is either the heat flux (misleadingly named "temperature flux") or the potential flux in ().