Hello Rob I have a quick update on my last message. Originally as mentioned above I was importing a CAD STEP from Rhino 7 into spaceclaim under MM units. This was sent to fluent with meshing which automatically converted the units from MM to M. Total skewness was 0.41 with a ortho quality of 0.50. This produced a total of 2.8 million elements. This was then imported to solver and run. Now once I created my volume in space claim I saved my geometry file as .sdoc from spaceclaim. I opened fluent with meshing as a individual module and imported the spaceclaim doc which allowed me to manually set my units which I did to MM. Now I ran the mesh with the same sizing just different for units and ended up with a 42 million element mesh. Clearly this is a massive change. I feel I am doing something wrong but my units are definitely now in MM as the CAD and not M as the first simulation. Could this be why I was getting such an error in my pressure ? Perhaps the element sizing was off due to fluent switching my units around ? 2.5 million to 42 million seems like a massive jump. I went with the settings recommended to me by ANSYS in the mesher. If you have any suggestions that would be helpful. Thank you.