### 6.3.1. Stopping and then Restarting Simulations with an Increased Number of Time Steps Per Period

In many flow simulations, it may be advantageous to start the simulation with a low number of time steps per period in order to pass through the initial transient phases of the solution, then later increase the number of time steps per period to accurately capture the flow physics. For a large simulation, this strategy can help reduce the overall simulation time required to reach convergence.

You can stop a Time Transformation or Fourier Transformation simulation and then resume it with an increased number of time steps per period.

An important constraint on how you increase the number of time steps for Fourier Transformation simulations is that the number must be doubled. For example you could start with 40 time steps per period, then restart with 80, then 160.

There is no such constraint for Time Transformation simulations. For example, you could start with 40 time steps per period, then restart with 50, then 70.

Release 18.2 - © ANSYS, Inc. All rights reserved.