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-   -   CavitatingFoam for Diesel injector nozzles (http://www.cfd-online.com/Forums/openfoam-solving/58726-cavitatingfoam-diesel-injector-nozzles.html)

javier_salvador July 16, 2008 10:37

Hello everybody! I'm using
 
Hello everybody!

I'm using cavitatingFoam (in O.F. 1.4.1) to simulate cavitation in diesel injector nozzles. At the moment, I'm using a simple geometries for which I have experimental mass flow results (axy-simmetric orifice with diameter of 0.15 mm.). The problem is that, even for low inlet pressures (150 bar) and for a given backpressure (i.e. 5 bar or 10 bar) when calculating the mass flow rate in the outlet section it shows a very high time variations (oscillations with high amplitude) when it is supposed to be converged and cavitation appearance (gamma) seems to be very stable. I'm using Courant Number =0.12 and acoustic Courant Number 12.5 (as Dr Weller proposed). Curiously the observed instabilities seem to be smaller for a backpressure of 1 bar, when cavitation is supposed to be more intense. The time step (automatic) is around 1e-9, and at the end of the simulation (1e-3) residuals are very small. I have tried with different quality of cells (in all of them the wedge angle is 5) and it doesn't seem the origin of the problem.

1. Could anybody help me please?

2. Does anybody know whether Dr. Schmidt's model is implemented in Open Foam? I know that in his model the numerics is specially useful for high Reynolds numbers as in my case (I would like to simulate injection pressures of 1000 bar or even higher)

Thank you very much for your time.

I'm very pleased to have known some of you during the 3rd workshop

Best Regards

Javier


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