[Ankit Patel]

Hello everyone!

I am using ANSYS Fluent 2020 R1 for simulation of compressible air. I have attached one sample of isomeric geometry for which simulation have to carried out. The experiment is all ready carried out and I have to carried out simulation for same.

Boundary Conditions,
Inlet: Pressure (7 bar, Fixed)
Outlet: Pressure (Varying between 6.5 bar and 3 bar)
Wall: Stationary wall, no slip
Target: To find mass flow rate for all boundary conditions

The steady, compressible and fully developed turbulent flow is there. From experimental data, the range of Mach number between 0.3 to 1.15 for given boundary conditions.

I have carried out simulation for one boundary condition with pressure based solver and density based solver and my mesh is fine for both the solvers. The result by pressure based solver is more nearer to experimental result compared to density based solver. For pressure based solver, SIMPLE scheme is used for PV coupling with second order upwind to other equations. For density based solver implicit formulation is used with second order upwind to other equations.

Questions:
(1) Which solver results should I consider for given Mach number range for my case?
(2) Are there any relation available for Mach number and selection of solver?

Thanks in advance.

[LoGaL]

they are bot fine for such mach number conditions. Density based solver is better for high mach numbers. If i have to guess a number, i'd say more than M= 3-4.

I would use coupled solver instead of SIMPLE and stick with the pressure solver.

Edit: you seem to speak about experimental data, so I would simply try them both and see which one matches the data better. But as I said, I think for these ranges, nothing so different will happen

[Ankit Patel]

Ok, Thank you for guiding me.

[Ankit Patel]

As per your edited response, "I should consider the results nearer to experimental results by any these two solver?"

[LoGaL]

If it is not too long to run the CFD, run it with both solvers and compare with experimental results you have. Then for any further work use the solver that predicted the best results

If you don’t want to do it, stick with coupled pressure solver

[Ankit Patel]

Ok, I will do simulation with both solver compare with experimental. If there will any queries then I will contact you.

Again, Thank you for guiding me.

[Ankit Patel]

Is there any journal paper in which they compare the results of pressure based solver and density based solver with experimental data and give conclusion?

[LoGaL]

i googled them -.-

https://hal.archives-ouvertes.fr/hal-01894391/document


work from NASA (the name sounds cool yes)
https://tfaws.nasa.gov/TFAWS11/Proce...011-AE-001.pdf

also this bachelor thesis is fine
http://seanbone.ch/site/wp-content/u...n_SeanBone.pdf

Are you still stuck that you want to use the density based solver? As I said, either you want to simulate hypersonic reentry or there's no advantage in density based solver

[Ankit Patel]

I have completed run with pressure based and density based solver and results are good in pressure based with experimental.
I just need the references to add in my report.

Thank you

[LoGaL]

good luck then