Learning Forum

[IFarozan]

Dear all,

I am performing a 2D simulation of a savonius wind turbine using the MRF method. The material is air with default properties. A velocity inlet with 7 m/s speed, a pressure outlet with 0 pa, symmetry for top and bottom border, a moving wall (relative to adjacent) for the rotor walls. I am using coupled solver with k-omega SST turbulence model.

Convergence criteria is 10^-4 for residual and 10^-4 for rotor torque value. The simulation was run in steady state with no problem and convergence reach around 500-900 iteration. During the simulation run, i put a monitoring plot for the moment along Z axis, with moment center at 0,0. The center is exactly at the rotor center as i made it in spaceclaim.

The value of the torque from the monitoring was stable at around 0.2417 N.m. however, when i print the result>report>forces>moment with the same moment center and axis and wall, the result is significantly different (0.0556 N.m).

The question is, whether the torque from monitoring and result>report computed differently, eventhough on the same axis and center? Or is there any other factor which leads to this difference in value?

SOme attachement related to the case. Thank you for your kind assistance.

[Amine Ben Hadj Ali]

Can check the force values?n

[prajput]

Hello Array,nFor moment definitions, please check out section 30.2.1. Computing Forces, Moments, and the Center of Pressure in the ANSYS Fluent Theory guide. Also compute and compare the Force values reported via a monitor vs report forces.nHope this helps.nBest Regards,nPankajn

[IFarozan]

Hi DrAmine and prajput,nThank you for your suggestions, and i appologize for late response. I currently have no access to the project file yet as i am away from campus. I will check the suggestion and will get back with follow up as soon as possible.nBest regards,nIvan Fn

[IFarozan]

Sorry for the long update. I have found that the computed moment (from result>reports>forces>moment) is the result of the plotted moment value multiplied by the depth value in the reference values.nThe plotted value is showing for 1 unit of depth (i.e 1 m), while the computed result is for the actual depth filled in the references value.nI've mark the answer in this thread accordingly, and thank you for your kind assistance.nnIvan Fn