I am currently trying to get a good viscious mesh of a 3-d wing. I have a volume composed of the wing subtracted from a box. However when I try to attach a boundary layer mesh to the surface or edge of the wing, the direction of the boundary layer is either into the wing itself, or along the surface of the wing. I have tried read through the gambit manual and have tried middle shift clicking on the surface or edge to change the direction but it does no good. Does anybody really understand the voodoo of the boundary layer meshing subpad, if so I would greatly appreciate the help.

thanks, -Rick

When you choose the surface or edge to which apply the b.l. be sure to choose the one relative to the box and not to the wing.

I'm a little confused, what do you mean by "chose the [surface or edge] relative to the box and not the wing" If I select the surface or edge of the box, it only makes a BL mesh on the surface or edge of the box, which is the outer boundary of my fluid volume. The box is significantly bigger than the wing in all directions.

-Rick

When you click on the wing surface/edge to apply the b.l. probably Gambit select the surface/edge on the wing side; instead you need the surface/edge on the box side. So I suggest to select the (box) surface/edge by selecting it from the edge/surface list.

I've tried selecting the alternate volume/face attachments of each face/edge I'm trying to put a BL mesh on, but none of them point outward from the wing. I even went through and deleted all volumes except for the fluid volume that I got from stitching the wing and box faces together. One would think that since the volume only exists in the region between the box and wing that the mesh could only exist within that volume, but it keeps trying to make the boundary layer go along the faces of the wing, which helps me none.

thanks for the advice, -Rick

Hi Rick, You can try this one:- You can make surfaces perpendicular to the surface of the blade. Then make 2-Dboundary layer on these surfaces and them mesh them using cooper scheme. There might be other techniques also.

hope this helps bharat

[IvanCFD]

Hi Rick,

I'm experiencing the same problem as you did few years ago - boundary layers pointing inwards a wing.

I'm wondering how you managed to sort it out.

Cheers,

Ivan.

[amin_jalalian]

Hi
I subtract one brick from one bigger. I want boundary layer meshing on it. but when I select each face of inner hole, direction is inward!! what can I do? thanks.