Calculating turbine RPM in a pipe with known air velocity and diameter

[matth6197]

Hello,

I am trying to calculate the turbine RPM for a turbine in a closed pipe. I know the air velocity and pipe diameter. Can this be done?

 

[Lnewqban]

Welcome, @matth6197 !

The lighter the resistive torque or resistance at the shaft of the turbine the higher its rotational speed should be.

 

[anorlunda]

Is your turbine just a propeller or a fan blade. If so, then the pitch of the blades is the most significant factor in RPM.

 

[Al-Layth]

I hope somebody posts a detailed answer for how this calculation is done. I am dealing with a similar problem for wind turbines.

I expect you will somehow need to calculate the lift on each turbine blade multiply by the number of them and model it as a circular motion problem. but then you also need to take into account the change of lift per blade due to the fact the blade will spin, (whereas it was stationary at first) and also the effects of the spinning blades on the incoming fluid as well. All issues currently beyond my modelling abilities