MES: Równanie ciepła

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Równanie ciepła

Lokalizacja w menu
Rozwiąż → Równanie ciepła
Środowisko pracy
MES
Domyślny skrót
brak
Wprowadzono w wersji
0.17
Zobacz także
Poradnik MES

Opis

To równanie opisuje przepływ ciepła w ciałach sztywnych i płynach.

Informacje o teorii stojącej za tym równaniem można znaleźć w dokumencie Elmer models manual, w sekcji Heat Equation (równanie ciepła).

Użycie

  1. Po dodaniu solvera Elmer zgodnie z opisem na stronie solvera, zaznacz go w widoku drzewa.
  2. Teraz wciśnij przycisk lub wybierz opcję Rozwiąż → Równanie ciepła z menu.
  3. Zmień ustawienia solvera dla równania lub ogólne ustawienia solvera jeśli to konieczne.

Ustawienia solvera

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

The heat equation provides these special settings:

  • DANEBubbles: 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 DANEBubbles and DANEStabilize are false, no stabilization is used and then the results might easily be nonsensical.
    Note: If during the first solver iteration you get this error:
    ERROR:: IterSolve: Numerical Error: System diverged over maximum tolerance.
    The DANEBubbles method failed. In this case set DANEStabilize to true.

Equation:

  • DANEConvection: The type of convection to be used in the heat equation.
    Note: If this is not set to None, DANEStabilize must be to true otherwise the convection term will not be considered for the heat equation.
  • DANEPhase 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.

Analysis Feature Information

The heat equation takes the following analysis features into account if they are set:

Note

Except for calculations in 2D, for all the above analysis features it is important that they act on a face or a body. Constraints in 3D set to lines or vertices are not recognized by the Elmer solver.

Result

The result is the temperature in Kelvin.