torque function

João Soares · March 31, 2016, 13:54

Hi

Im trying to calculate the Input Power (radial impeller) = torque x angular velocity
I read that torque is determined by
M = ||SUM {Fi x Ri}||
The force vector is calculated as a sum of vectors Fni and Fti

I defined a new coordinate system at the center of rotation, and in CFD - POST - FUNCTION - TORQUE, is it applied on the blades and impeller side walls(Hub/shroud)?

I have searching for this in the helps and tutorial documentation, but having no luck finding a solution. I would like to know if someone can explain to me how can i find the torque.

Thanks

turbo · March 31, 2016, 15:00

If you ask for impeller CFD, what you try to get is called "aerodynamic power", not the real input power in testing (because you handle with flowpath only). Forget about torque for that. Aero power (kW) = mass flow (kg/s) * Delta Enthalpy (kJ/kg).

March 31, 2016, 13:54	torque function	#1
João Soares New Member Pedro Ferraz Join Date: Mar 2016 Posts: 2 Rep Power: 0	Hi Im trying to calculate the Input Power (radial impeller) = torque x angular velocity I read that torque is determined by M = \|\|SUM {Fi x Ri}\|\| The force vector is calculated as a sum of vectors Fni and Fti I defined a new coordinate system at the center of rotation, and in CFD - POST - FUNCTION - TORQUE, is it applied on the blades and impeller side walls(Hub/shroud)? I have searching for this in the helps and tutorial documentation, but having no luck finding a solution. I would like to know if someone can explain to me how can i find the torque. Thanks

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March 31, 2016, 15:00		#2
turbo Senior Member Join Date: Jun 2009 Posts: 174 Rep Power: 16	If you ask for impeller CFD, what you try to get is called "aerodynamic power", not the real input power in testing (because you handle with flowpath only). Forget about torque for that. Aero power (kW) = mass flow (kg/s) * Delta Enthalpy (kJ/kg).