Calculated torque to low
 

Hi,
I´m calculating forward curved centrifugal fans in steady state with SST. Grid is ICEM structured, y+ 2...30.
The throttle curves are in (very) good accordance with experimental data (deviation < 5%). But calculated torque (needed for calculating efficiency) ist ~ 25% to low.

Has someone an idea why? What does the torque function (torque_X@...) exactly do? How ist the mathematical or numerical equation? Is there a "changeable" coefficient??

Greetz
Adam

Thanks, but this isn´t very helpful.

I checked different models, grids...and I´m advanced in CFD.

So:
Measured throttle curves (with a chamber test rig) as well as measured velocity fields (with PIV) are in (very) good accordance with the simulations...BUT NOT the torque?!

Anyone an idea?

Then you would know that unless the basics are covered there is no point proceeding - you made no mention of that in your initial question.

I do not have any answers for you, but this exact question has been asked a few times. Makes me suspicious that there is something wrong in the software in evaluating torques. But I have no idea what.