what does negative torque value mean in CFD post?

  • Last Post 11 November 2019
mechguy1 posted this 11 November 2019

I am trying to find the power of vertical axis wind turbine. I have setup a problem as below.


tansient K-omega SST model

inlet velocity is 10m/s.

Rotor velocity is 200rpm I checked the frame motion box.

Rotor rotates around Z axis. 

all other settings are left default.


The problem here is 5 blade design should have higher torque values as per the general physics. 


I have attached the image of my torque results. Thank you in advance.


Attached Files

abenhadj posted this 11 November 2019

Check the CFX tutorial which explains why you should consider the absolute value. Torque you get is what the Fluids exert. But you provide power to rotate the impeller.

Best regards, Amine