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High torque coefficient Cm for Vertical Axis Wind Turbine (VAWT)
Hello,
I am modelling the 2D vertical axis wind turbine (VAWT). The turbulence model is k-epsilon with std wall function. I simulate 4 angular velocities: 5, 10, 15 and 20 rad/s. Wind velocity is 11 m/s. Model is using U-RANS with sliding mesh. Problem is that I obtain excessively high torque calculated from the Cm (4 to 5 times larger than it should be). Cm is obtained from Fluent, torque calculated with the Cm definition(Cm=T/(0.5 x rho x v^2 x A x R). Time step: tried both time steps corresponding to 1 degree and 1/8th degree. Results perfectly match so the 1deg step is fine enough. I would be very grateful to the one who can spot if and/or where I am making a mistake and can contribute to making this simulation happen the best way. Thanks All the best TonyMac |
that might sound - and actually be - silly but check that you actually divided the torque by the appropriate value, to get a reduced coefficient instead of a Nm torque. That happened here not too long ago.
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Hello Benoit,
all solved and getting pretty good results now. As you suggested it was indeed a problem with the constants entered in report-> reference values. Thanks Tony |
Change fluent reference values
Change fluent reference values
compute velocity form inlet and change reference area to swept area your cm will change hope this work |
Quote:
I m also facing the same problem. still i m not able to reasolve the fluent case. please give some idea to predict the Torgue and Co efficient of the performance (Cp) of the wind Turbine. With Regards S.SIVAKUMAR |
Hi tony, maybe I'm affected by the same problem you solved.
I hope you will share with me your solution. Thanks |
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