Geometry Fix
 

Does anyone have any idea on how to make this wing geometry ( in the picture) water-tight? First one is picture of tip of the wing and trailing edge. Second picture is another view of the wing. I have the same problem at the root. I also found some leak locations in my shell mesh ( see third picture). What can i do to get rid of these leaks and holes.

It is hard to tell if the first image is just the rendering of your model not being displayed properly, or something more serious like a surface not being attached to a curve. However, if the third image is displaying the curves "Coloured by Count", then the geometry is fine, and the hole is just a bad rendering.

I see that you are using octree to create this mesh. You will probably need to decrease your edge criterion for ICEM to capture this sharp edge. Another way of achieving this without affecting the rest of your model would be to "Define Thin Cuts". Look for both of these options in the help index for information on how to use them.

Stu