- GuiCommand: Name:FEM EquationHeat MenuLocation:Solve → Heat equation Workbenches:FEM Version:0.19 SeeAlso:FEM tutorial
This equation describes the heat transfer in rigid and fluid bodies.
For info about the math of the equation, see the Elmer models manual, section Heat Equation.
- After adding an Elmer solver as described here, select it in the tree view.
- Now either use the toolbar button
or the menu Solve → Heat equation. - Change the equation's solver settings or the general solver settings if necessary.
For the general solver settings, see the Elmer solver settings.
The heat equation provides these special settings:
- Bubbles: There is also a residual-free-bubbles formulation of the stabilized finite-element method. It is more accurate and does not include any ad hoc terms. However, it may be computationally more expensive. If both Note: If during the first solver iteration you get this error: ERROR:: IterSolve: Numerical Error: System diverged over maximum tolerance.The Bubbles method failed. In this case set Stabilize to true.
Equation:
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Convection: The type of convection to be used in the heat equation.Note: If this is not set to None, Stabilize must be to true otherwise the convection term will not be considered for the heat equation.
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Phase Change Model: The model use for phase changes (ice to water etc.). The model Spatial 1 is the apparent-heat-capacity method, Spatial 2 and Temporal are effective-heat-capacity methods.For more info about the models, see this paper (section 2.5.2.2) (is in German). In the paper it was also shown that Spatial 1 has numerical problems on larger temperature gradients and that Spatial 2 was preferred for the phase change ice to water.
The elasticity equation takes the following constraints into account if they are set:
Except for calculations in 2D, for all above constraints it is important that they act on a face or a body. Constraints for 3D set to lines or vertices are not recognized by the Elmer solver.
The result is the temperature in Kelvin.
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