[fall3n]

Hi all,

I am currently trying to model a 2D VAWT experiment in Fluent, but have failed to obtain the right plot of Cp vs TSR.

I ran the MRF with the RNG k-epsilon with enhanced wall function and took moment reading at the center of rotation. However, my moment reading are all negative. Furthermore, when normalized to Cp, the readings does not follow the usual VAWT behavior.

The results are as such:

TSR rad/s Torque Ct Cp
1 8 -3.9113711 -0.020434918 -0.020434918
1.5 12 -8.9829710 -0.04693144 -0.07039716
2 16 -3.5845858 -0.018727632 -0.037455264
2.5 20 -12.263571 -0.064070902 -0.160177254

Where the Cp values are negative and does not peak at the usual TSR of around 2.

I have read the forums and noticed problems with other user, but have failed to find a definite solution for this problem.

Please let me know where i may have went wrong. Thanks in advance!