Savonius wind turbine data extraction
 

Hello everyone, I have a question regarding data extraction. My ultimate objective is to determine the rotating speed of the wind turbine.
Below is my simulation setup(it's an overset mesh). I am simulating a train passing a wind turbine. I am hoping to get an answer on how can I determine the rotating speed of the wind turbine.
I have tried to look up the method of how to acquire this number as TSR is mentioned much time but I am how to estimate a TSR value as this wind turbine is only a virtual one (blade diameter of 1.5m).
https://imgur.com/a/eYChBBv
Any bits of help is appreciated. Thanks in advance.:)