[Nektar-users] determination of time step

Dear all, For a simulation with IncNavierStokesSolver, what is an appropriate way to determine the time step? I did an estimation using the CFL criterium. Due to the spreading of the cell size this leads to a wider spreading of possible time steps. Is there a command to plot the maximum CFL number during the calculation? Exists the possibility to give a CFL criterium and the time step is calculated by nektar? Kind regards, Albert