[saikath65]

Hello,

I am simulating a savonius wind turbine using k-omega SST model, coupled scheme. All the residuals are converging below 1e-5. But the monitored moment is not converging. Timestep is suffieciently small, turbine advances 0.5 degree for each timestep. The simulation has already run for 22 turbine revolution.

Still the monitored moment is not becoming steady and fluctuating each revolution. I think the mesh is fine enough. When the same mesh is used and SIMPLE scheme is used the moment converges within 7-8 turbine revolutions.

I am attaching two photos. One is the monitored moment. Another one is the comparison of moment between 20th, 21th and 22th revolution of the turbine.

So is this acceptable convergence? or What's wrong? Thanks.