Hi Prashanth,

Thank you for your reply. I have used watertight workflow to genetate polyhedral mesh with 5 boundary layers. The mesh size is 1mm in the wake region and recirculation zone. The computational domain is 10D long and the gas is fully expanded. 

I have then re-generated poly-hex core mesh and the results were similar to the polyhedral mesh. 

Could you please advise that is there a meshing problem or something else? Many thanks