I want to define a rotating fan, but am not able to fand the proper boundary condition to apply for this purpose. i am using GAMBIT as the preprocessor... can anybody help me???

have you tried with ansy? in my opinios is better

i dont have that software available with me and couldnt find details on simulation of fan anywhere... if anyone cud help me i would be very happy

I know that you can use the rotating frame of reference model to simulate the motion of the fan blades. Look at one of the tutorials on rotating frames of reference

You can model a in 3-4 different ways in fluent with increasing orders of computational effort and accuracy. I have listed them choose according to your requirements. 1. "fan" BC in fluent - all u need to do is create a circular surface where the fan sits and apply this BC. Like you would expect this is the least accurate. 2. Multiple Reference Frame method - here u need to use the actual fan geometry and create a volume around it to use as a MRF zone. The size of the zone is critical for accuracy See fluent guidelines 3. Sliding mesh - it is the most accurate and most computationally intensive method. Start with the solution of the MRF method. it models flow as unsteady. 4. You can write your own UDFs for a fan