Introduction

Initial values for all solved variables need to be set before the solution can begin. If your calculation is a steady-state calculation, the initial variable values serve to give the ANSYS CFX-Solver a flow field from which to start its calculations. Convergence is more rapidly achieved if sensible initial values are provided. However, converged results should not be affected by the initialization.

If your calculation is a transient (unsteady) calculation, then initial values provide the flow field at the time when the CFD calculation starts. If you are starting a transient calculation without using a previously created results file as an initial values file, then you must set each solved variable to the initialization option Automatic with Value. The values specified should be the actual flow field present at the beginning of the time of the simulation.

Initialization can be controlled on both a domain and a global basis. Domain initialization will take precedence over global initialization for any domain in which it is specified. You can access the domain initialization forms when creating a domain in ANSYS CFX-Pre. For details, see Initialization Tab. The global initialization settings are accessed from the Global Initialization icon in ANSYS CFX-Pre. For details, see Initialization.