Regular Hex mesh in ICEM
 

I am really stuck in meshing the following case. How can i create a purely regular hex mesh with denser mesh in the centre and less dense in the outer region in the following case. I tried the blocking strategy but seem so complicated. I attached the picture of my case and the mesh i wish to acquire. Thanks for the help.

Refine with ogrid or 2 to 1 refinement
 

You could use Ogrids relatively easily... Just start with the HGrid and then apply apply the OGrid at the end... It should be just a matter of selecting the blocks. This will naturally focus all the mesh on the center of the cube. By adjusting the OGrid edge length, you can control the focus (also easy to do with "rescale Ogrid").

If your solver (like Fluent) can handle hanging nodes, you could just use the 2 to 1 refinement option and refine the blocks where ever you want.

If it can't handle hanging nodes, you could use the 3 to 1 refinement option and then "resolve refinements" so that everything connects up... I will add an animated gif to illustrate.

I am so sorry, i dun really get ur idea, would you mind to explain in more details?