Ansys Icepak can solve the equations for conservation of mass, momentum, and energy in time-dependent form. Thus Ansys Icepak can be used to simulate a wide variety of time-dependent phenomena, including transient heat conduction and convection, as well as transient species transport.

Activating time dependence is sometimes useful when attempting to solve steady-state problems that tend toward instability (for example, natural convection problems in which the Rayleigh number is close to the transition region). It is possible in many cases to reach a steady-state solution by integrating the time-dependent equations.

Ansys Icepak uses a fully-implicit time-integration scheme for transient analysis. This chapter provides details about setting up a transient simulation in Ansys Icepak and postprocessing the results. See Time Discretization for details about the theory of transient simulations.

Information on transient simulations is divided into the following sections: