[Jonny6001]

Hello,

I am looking at simulating a shaft rotating inside a cavity of air with the aim of monitoring the torque on the shaft due to viscosity. Added to this I would like to have the actual shaft solid part in the simulation so that I can see how the viscous heating affects the shaft temperature.

I have already ran the simulation with a "fluid only" domain whereby I specify the tangential velocity method on the surface that coincides with the rotating shaft surface. I have got good results using this method. I now want to include the solid shaft in the simulation. I have tried several methods but I always seem to get very low torque on the shaft compared to the tangential velocity method, they should be exactly the same.

I have the full fluid and solid regions and have defined an in-place contact interface where the shaft is in contact with the fluid. If I specify a tangential velocity for the contact interface between the fluid and solid I get zero torque on the interface. I have also tried to set the solid shaft region as a moving reference frame but get the same results.

It sounds like it should be a fairly simple method because essentially I have a shaft rotating in a fluid that I want to simulate.

Any help would be greatly appreciated.

Thanks