ANSYS CFX Turbo-machinery Setup Question
 

Hi everyone,

Hope you are all well. I am currently conducting some CFD simulations in CFX with a micro gas turbine stator and rotor system. However, I am confused by some online tutorials about the turbo setup. I have seen some people set up the model with the whole rotor fluid domain rotating at a specific RPM. But I think the turbine parts that are rotating are the rotor hub and blades (assume there is a rotor shroud tip clearance). Therefore, I think the correct way is to set up a stationary rotor fluid domain; then, specify mesh deformation in the R1 fluid domain and a wall rotating velocity to the rotor blade itself.

I tried to simulate both cases (rotating fluid domain and rotating blades). May I ask if anyone knows which model should I choose?

Thank you in advance for your help!

Hi;
Rotating blades in turbomachinery flows are always solved with respect to rotating frames while the stationary ones are solved with respect to stationary references. The reason is that from view point of a stationary reference frame the flow field of a rotating row looks unsteady. Therefore this approach is used to make the simulation steady. You may ask if stationary and rotating rows are solved in different reference frames, how they can be linked together? The answer is that this can be done through proper definition of their interface. A popular options that most commercial softwares use is "mixing plane" method.

Best

Hi Hamidzoka,

Thank you for your explanation!