Discussion Forum

Hi All,

I'm trying to model an alternative type of turbine, which is a version of vertical axis turbine that is deployed horizontally in a micro hydro electric power setting.

I'm relatively new to COMSOL, but I think I've created an accurate geometry model for the turbine. However, when I try to mesh the geometry, I'm getting numerous errors around edges being to small to compared to the element size. I've tried to mesh on the smallest size, but I still have the issue.

I believe the issue comes from the fact that the blades slightly overlap their casing (Turbine rotates with casing, not on a central axis), however this is key for providing a flush finish. I attempted to use a union to remove the interior boundries, between the overlapping blades and the casing. This works at one end of the turbine, however, at the opposite end the interior boundries aren't removed and I believe this is causing issues???

I've also tried changing the mesh manually, but I'm still getting the same issues.

Any meshing tips would be greatly appreciated!

Also my final goal is to calculate the torque of the turbine, and my current calculate is to perform a surface intergration with the expression:

p(nyx-(y+0.2)*nx)

I'm also just using the turbulent flow physics package. If anyone can let me know if im on the right lines, or if I should be using a different physics package to find the torque from the flow please let me know!

Sorry for the questions!

Tom