I managed now to calculate the flow coefficient and could verify it with the test bench.

For the swirl i need some further help please. I would like to calculate the swirl in a plane. The swirl at the test bench is defined as tangential velocity over axial velocity. I now use the area weigthed average in the defined plane for axial and tangential velocity and calculate with that the swirl. The results deviate from the test bench. Is the way i calculate it wrong or is there a better one?