I have very simple model where inlet temperature is stepped up and the response at different locations in the room is extracted. Unfortunately I could not get an idea how small/large the time step need to be and the corresponding number of iterations. I tried between 0.5sec and 5sec but I am getting strange response just after the step, but later on improves. Any help is appreciated

CFX 4.4 users

Hi,

What do you mean by "strange response"?

Glenn

First start with a well converged solution for the start temperature and calculate for that case the first ten or more time steps. After that you can start you stepping on of the inlet temperature. I bet this is the key. sascha