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ayothicfd July 23, 2012 22:31

Fan simulation divergence
 
Hi everyone,
I am doing FD fan in ansys. I have noticed divergence problem while doing the mass flowrate of 53.54 kg/s and above with IGV 30 deg inclination. I have taken a backup file of the same run while getting diverged in which I have gained some idea that the pressure value at stator-rotor interface is getting too large (around 2 lakh pascal). So that, I have given the interface option as frozen rotor instead stage. And, It is getting converged for the above specified mass flow. I checked the same simulation by changing the interface option as stage through the converged result as initial file. It is also getting diverged and stopped. Is there any problem while doing interface option as stage? or do I have to look any important things before using stage interface?
Thanks in advance.

csmistry July 28, 2012 04:41

The CFX uses two interface models: 1. Stage and 2. Frozen rotor. When you are running your case for turbo machines if it is having stator and rotor both. than two separate domains (Stator and rotor) need to be connected by one of this model

The stage option selects the mixing plane approach which transfers the data from one domain to other. the problem with this concept is it is not exactly transferring the values to next an seen for multi stage turbo machines.

When u have two rotating domain than it is batter to opt frozen rotor option where this mixing plane problem can be resolved. still for some of analysis expert uses stage option. If you have itlet data to rotor than it is batter to avoid interface option.


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