Alright thank you. However may I know if there is a difference between using Hex-dominant method and using multizone method (hexa)? 

Since I am not able to use the Hex-dominant method for CFD, will multizone method (prism) or tetrahedrons be better? 

When comparing the mesh quality metrics between the multizone method (prism) or tetrahedrons, the quality of multizone method (prism) is better. However I understand that prism is considered a 'wedge', so in this case, I am unsure of what to use for the mesh setting for CFD. 

I am solving this in the 3D Computational Grid.