Hi all,

I am getting self-intersection after generating the subsurface eventhough if i enable avoid self intersection in advanced options. The interesting thing is the self-intersections are not in the subsurface regions but some were in the model. How to avoid this error?

Try doing it manually. Select the cells where the self intersecting is happening and change them to a different cell type. Then use the advanced options in the subsurface generation panel to set these cells at a diffent thickness.

Another way is to just set all cells at the lower value, but this will screw up more y+ values. Good luck, Tom

hello Tom & all.

I have the same self-intersecting problem after the sub-surface generation.

I have a duct model, in which i have a sharp corners. after sub surface generation i found that the subsurface is going up and intersecting with surface in the sharp corner.

I have tried playing with advanced options and different cell thickness for the region where i am getting problem. but nothing works the way i excepted.

The one way may be putting the intersecting region to no sub-surfrace. but that doesn't make any sense since the region is very critical to the flow.

Do any one know, how to solve this.?

Regards,

nava

Hi all,

Sometimes I also got the same self-intersection error although I knew my shell surface was clean. What I did was, I would do a surface check before I proceed to sub-surface generation. Then I find attach those self-intersection shell and re-create new shell on those area. * To find attached shell, I use this method 1. new vertex set -> cell set 2. new cell set -> vertex set any

Hope this will help!

Airfoil

You can also plot a contour plot with surface+subsurface and by that plot you can find intersectiong cell (subsurface menu->Plot...->Subsurface and Thickness Contour). The you can try to remesh the intersecting zone of the surface and then doing a new subsurface or you can change cell type in that zone and create a subsurface with different wall tickness

In the Advanced Subsurface Options there are two parameters which can help with self intersection problem - number of iterations and relaxation factor.