Hi, I am working on small scale wind turbine. I use Ansys Fluent to investigate the rotor performances. Prior to the study, a mesh sensitivity test was conducted, the results of this study are presented in the table below. I want to know your opinion about these results.
Thank you.
You can plot this data as a graph (No. of elements vs Power), to obtain a better understanding of your mesh convergence.
I agree with the advice of R.A. Ghazalla . It is not yet sufficient to pump more and more grid cells into the volume of your fluid domain, but a mesh convergence study needs to be conducted more systematic and sophisticated. The mesh convergence study has to assure, that by mesh refinement ALL flow gradients become more and better resolved with each mesh level. This of course starts with all flow boundary layers, as R.A. Ghazalla has suggested, ending with resolved boundary layers with 20 mesh layers on wall boundaries and y+~2-4 at least. But it applies to strong flow gradients in e.g. turbulent wakes in the downstream of your turbine as well.
Regards,
Dr. Th. Frank.
Dear @Somaya
I have to agree with @R.A. Ghazalla and @Thomas Frank.
Additionally I suggest you to include other parameters in you mesh sensitivity test, for example velocity, pressure and other that you judge important to your study. That will make possible a better visualization of how other parameters work.
The other this is that you should also check the orthogonal quality and skewness, they are available from the quality menu in the meshing editor. In the following link you will find a chart showing what are the reference values for these two parameter :https://www.researchgate.net/figure/Skewness-and-orthogonal-quality-mesh-metrics-spectrums_fig2_320786408
Goos luck
I agree with all the suggestions. Normally, for me, I am satisfied if the error between the last and before the last results is between 1-3 %.
Have a nice time.
It seems like there's one convergence criteria (or more) that is more influential on the results than the mesh in this case.
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