Hi everyone:

I am simulating a hydraulic turbine using cfx. I specified an angular velocity for the rotation domain. The rotating velocity is not a constant one, so the rotor would accelerate aroud its axis.Then I should get zero net torque.I don't know what a net torque is.Whether is it equal to "drive torque" subtract "resist torque".I know that the drive torque come from the water.But what about the "resist torque"? We can understand it when we do experiment.However, we are doing numerical simulation.

Could anybody tell me how to calculate the net torque of the rotor.

Best Regards, Mangnan

Is anybody know about what net torque mean?

Hi Mangnan,

It is Newton's Law of Motion - a body will accelerate if it has a net force or torque. For constant linear or rotational velocity you need zero net force or torque. It's first year university stuff.

Glenn

Hi Glenn:

Could you tell me how to calculate net torque?

Best Regards, Mangnan