Learning Forum

[Mohamed Ramon]

How to calculate time step size , number of time step and max iteration ?

[Federico]

The time step size will depend on your physics. You want to select the most restrictive time scale that resolves the desired physics of your flow. One example is the convective Courant number, where you'd want dt < dx * V_flow.

The number of time step depends on the desired duration of your simulation. Do you want to simulate for T = 10s with a time step size of dt = 0.01s? n = T/dt = 1000

The Max iteration is a limit on the number of iterations that you want the solver to take for each time step. In general, if your solution converges intra-time step in less than 20 iterations, this would be considered efficient. Again, this will depend on your overall setup, physics, etc.