[spl]

Hi

I'm running a transient simulation for a radial turbine and I would like your advice on time step size and number of iterations per time step. A number of studies have used times steps range from 0.6 degrees per time step to 6.5 degree per time step but very few have stated how many iterations are used per time step. My understanding is that less iterations are required when using smaller time steps. So I have a few questions -

Is there a general rule for number of iterations per time for CFX?

What is the best method of judging convergence within a time step?

Is it best to select a number of iterations per time step (say 20) and then reduce the time step until the transient results are consistent or is there a better approach?

Thanks