volume meshing by layering alwayse failed.
 

----------------------+
　　　　meshing　　|
　　　inner　side　　|
　　　　　　　　　　 |
---------------------－+


I always meet the above type of geometry, an narrow, inward chamber.
When I use auto layers to generate boundary layer mesh (3D) , the top_cap usually collides with itself, and the meshing is failed.

Is there a possible way to make the collided top_cap merge and auto fill the 3D holes?

thanks in advance.