Negative torque_z()@blade

Alex123456 · August 24, 2015, 13:53

Good evening, help please. I am doing flow around the blade. With increasing rev/min^-1, torque_z()@blade becomes negative.

What is my fault?

Tried to swap the axis -- no results

When rev/min^-1, = 91 (λ = 4) -- all is well
with rev/min^-1, = 137 (λ = 5) torque_z becomes negative

ghorrocks · August 24, 2015, 18:16

Have a think about what this means. If the torque is negative then the rotor will slow down. This means you have exceeded the speed of the rotor.

That assumes your simulation is accurate. Your simulation could also be inaccurate - that is an FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

Alex123456 · August 26, 2015, 09:57

Thank you very much for your answer.I will try to understand.

August 24, 2015, 13:53	Negative torque_z()@blade	#1
Alex123456 New Member Alex Join Date: Aug 2015 Posts: 3 Rep Power: 10	Good evening, help please. I am doing flow around the blade. With increasing rev/min^-1, torque_z()@blade becomes negative. What is my fault? Tried to swap the axis -- no results When rev/min^-1, = 91 (λ = 4) -- all is well with rev/min^-1, = 137 (λ = 5) torque_z becomes negative

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August 24, 2015, 18:16		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Have a think about what this means. If the torque is negative then the rotor will slow down. This means you have exceeded the speed of the rotor. That assumes your simulation is accurate. Your simulation could also be inaccurate - that is an FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

August 26, 2015, 09:57		#3
Alex123456 New Member Alex Join Date: Aug 2015 Posts: 3 Rep Power: 10	Thank you very much for your answer.I will try to understand.