[mcampbell]

I am in the process of modeling a hydrocyclone in ANSYS CFX. I have done a good amount of research of previous work. For my purposes I have chosen to use the Shear Stress Transport turbulence model with Curvature Correction activated (SST-CC). I have started with a model that has a well-known solution so I can verify my methods (Hsieh’s series I 1988 experimental data). The model seems to be predicting the flow well as I have good velocity correlation. While the velocitiy correlation is very good the pressure drop from my CFD analysis (~33 kPa) is lower than expected. The literature states a pressure drop (46.7 kPa) with the associated flow rate that was found in experiment. Also, I have calculated the expected pressure drop using Plitt’s empirical based calculation (47.4 kPa) which matches the experimental values well.

My question is: What could cause this result? I know there is a bundle of details not mentioned at this point (boundary conditions, air core/multiphase) so ask if you have a question. This may be as simple as an error extracting the proper pressure value from CFX (I don’t think this is the case) to the turbulence model not being adequate to pick up the intricacies of this complex flow.