[sandisk]

Hi,
I am performing transient simulation of slurry flow in horizontal pipe, ( am new to CFD). I understand that slurry flow is best simulated in unsteady state. I am using mixture model and my sand conc varies from 0-10 %. However, I am not sure how to specify the time step size and number of time step.. My length of the pipe is 21 ft and I have discretized it into 750 points, so each cell length in z direction is 0.33 inches or 0.027 feet. My velocity of flow is 12 ft/sec. So , should I be giving time step as 0.027/12 = 0.00231 sec or abt 1/3rd of this value. Also, i read that time step size is set in such a way that the simulation converges within 5-7 iterations for each step. So i can leave the max iterations per time step at default values. But I dont know what criterion should be used for Number of time steps. Any help would be appreciated.