[Vimal Chaudhari]

I am working on the performance of Savonius turbine using Ansys CFX. Turbine domain motion is Rotating in CFX. I am getting trouble in the equation of Coefficient of Power and Coefficient of Torque in CFX. Guide me to find force, torque, Coefficient of Power and Coefficient of Torque in the form of equation in the form of CEL.

[ghorrocks]

You can get the torque on the device by simply taking all the surfaces which make up the rotating surface and using the CEL expression torque()@Surface Name. You can also specify which axis to take the torque around with torque_x, torque_y and torque_z. Likewise the force just uses the force and force_x/y/z functions.

You can also use the calculator in CFD-Post to calculate these functions in post-processing.

From the torque and force you can evaluate the functions for the other parameters depending on how you have defined them.

[Vimal Chaudhari]

Thanks for reply Glenn sir,
I am working on Savonius turbine which has 'S' shape two blades (At a 0 degree angle of rotation one blade has Concave shape and another has Convex shape) which are mounted on a central shaft. Turbine domain motion is Rotating in CFX.
So CEL expression 'torque_z()@SurfaceName' is appropriate to find torque produce by turbine ?

[ghorrocks]

As long as the rotation axis is the global Z axis and you have defined all the rotor surfaces as an object named "SurfaceName" - then yes it should work.