Steady state thermal analysis

A stationary temperature field calculation provides the temperature distribution in a system that is in thermodynamic equilibrium. The change in the state variables over time has been completed long ago. The time-dependent term is therefore omitted from the equation system.

In many technical applications, the change in local temperatures over time is not decisive for the assessment or is correspondingly slow, so that certain steady-state conditions describe the thermal loads accurately enough. In these cases a stationary temperature field simulation is completely sufficient.

Computation time / model size

Stationary temperature field simulations are significantly less computationally intensive than transient simulations. On the one hand, this is due to the fact that only individual points in time and not an entire time range have to be considered, and on the other hand, because the reduced system of equations is less complex to solve.

In addition to the size of the model, the computing time depends strongly on the heat transfer effects taken into account in the model. Strong nonlinearities, such as phase transition or heat radiation, inevitably require more iterations and thus more time to find a solution.

Relevance

Temperature field simulation in general and stationary simulation in particular is of great importance in virtual product development. For many components, especially in electronics, a clear correlation between temperature and function or service life of the individual components is known from test data. In these cases, therefore, the maximum temperature is usually sufficient for the assessment.

In other cases, the temperature serves as a boundary condition and input variable for a subsequent structural analysis. The temperature is used to define the local, temperature-dependent material properties and the resulting thermal strains are then included in the evaluation of the component loads.