- This is the first and perhaps the biggest decision in CFD.
- Steady-state simulation computes the fully developed solution that does not change in time.
- When steady-state used the mean values are computed.
- The steady-state simulation is the way faster than transient.
- Transient simulation computes the instantaneous values in each time for each quantity.
- Transient simulation has much higher requirements comparing to steady-state. The CPU time, disk storage, evaluating results, ...
- The results of transient simulation may be more comprehensive.