[Goodstuff]

Dear guys,

I have fortunately managed to create a 2d geometry, based on 3d CAD model of a turbine, for my simulation (which is going to be performed in Fluent). I am currently meshing and have encountered some issues, that I don't feel comfortable with. In the first stage, I wish not to use sliding meshes right now, as my promoter advised me that, but rather than that perform a quasi transient simulation (3 stages of static simulation, no movement of the blades in each, just BCs).
[screenshots attached]

1)Is the boundary layer ok on the tip? Or should I make some additional division of the arc? I would prefer to fix it without having to turn off the advanced size function.

2)There are few distorted areas of the mesh visible on this screenshot. Not taking into account the inflation layers (which obviously require fixing) - do that kind of distortions influence the computation in any bad way?

3)Should I use pinch option to deal with the extremely small gap between the opposite blades/vanes in the central pair? It seems, that my inflation resulted in extremely small rectangles in the vicinity of the gap in both blade and vane - how should I fix this - I must not have a difference between the last cell of the b_layer and the first of the quad mesh larger than 30%. I have already tried to use it, but it seems to turn off the inflation (At least one pinch control has a tolerance below one or several scoped size control. Reduce tolerance or remove any pinch control(s) in close proximity of any such scoped size control(s), otherwise surface meshing might fail).

4)In few regions with proximity of boundary layers of vanes and blades, the automatic mesher develops cells of strange shapes, which have rather high Skewness - over 0.5 I think and there are more then 50 of them in the whole domain. Will that affect the computation - make it less reliable or not allow it to converge?

I would be most grateful if you could answer any of those questions!

Thank you in advance

Gustaw Cegielski