[aymaneed]

For my bachelor's thesis, I am working on a simulation for different designs of a Savonius VAWT.

I am using Ansys Fluent.

Since the rotor will be*rotating, I am using a moving reference frame for the sphere enclosing the rotor, and a stationary box enclosing the sphere.

My initial understanding was that I will specify the wind velocity, and that the rotational speed will be an output of the simulation in addition to the torque, pressure and other variables.

However the necessary moving frame of reference requires as input the rotational velocity.

I calculated a rotational velocity that will result in a tip speed ratio of 1 for the the wind speed I am using, and used these values to run the simulation.

My question is why do we have to specify both the wind speed and the rotational speed ? Shouldn't the rotational speed (and consequently the rip speed ratio) be resulting from the specified*wind velocity ?

How descriptive is the simulation in this case ?

Thank you in advance.