ICEM 5.0 - double meshing
 

Hi everyone. I tried to draw a concentric cylinder. The inner tube has inlet/outlet on the side and another pair in the midway. But everytime, i have double meshing (i am using hexa mesh). if i do the blockings and o-grids for the inner tube first and then the outer tube, the inlet/outlet on the side will have double meshing. if i do the other way round, and put the central block into VOFRON, the innertube will have double meshing. do anyone know how i can avoid double meshing? and how i can mesh this properly? thanks a lot. joan