[TimberJ3]

Hi,

I'm a student who is working in the modelling of the air at the intake duct of an engine for my final project and I’m asking for some advice.



Until now, I’ve been training myself working on the tutorial guide and some simple configurations with theoretical background such as laminar/turbulent pipes just to get familiarized with fluent (v.6.3.26).
After that I have been trying some simplified geometries that we have at the lab in order to validate the results with experimental data. The proprieties we are interested in are the variation of pressure between the inlet and the outlet as a function of the mass flow.


We are obtaining good enough results (deviation about 3-5%) for DeltaP between 10 to 200 mbar (velocity between 20 and 100 m/s) but deviations between 10-20% at higher and lower limits. the turbulence models used are k-e (simple and RNG models) and RS model with first & second order upwind equations.
Operating Pressure is turned to 0 and air is the material with density defined as ideal gas and viscosity with Sutherland’s coefficients in order to improve the results. Also mesh refinements based on velocity gradients have been tried and 3 different meshes.


Since results are not good enough for all the range of mass flow and I am running out of ideas, I would appreciate a lot some advice for next attempts.


Thank you in advance.