[GJM1991]

Gents,

I am currently doing my thesis on cavitation modelling and with that reason I started using openFOAM.
The solvers I am using (cavitatingFoam and simpleFoam) are working just fine but the resulting pressure (and thus pressure coefficient) I am obtaining with simpleFoam are not even close to the values found in literature and by other CFD-papers.
What I am trying to do is study cavitation behaviour of a 'hemispherical head', this case has a lot of experimental data by Rouse & McNown (see attached picture of Cp-plots) and it indicates that the pressure coefficient should be around 1.00 on the nose and about -0.75 for the lowest pressure. This is also confirmed by a thesis written by R.W. Erney (see attached picture of pressure field around head shape) who also used simpleFoam to verify the single phase (without cavitation) pressure coefficient and finds high value for pressure: 37.11 and low value for pressure: -24.76. This comes close to the experimental pressure coefficient knowing that the free stream velocity is around 8.27 m/s.

In my simulation I have setup a case with boundary conditions identical to the case simulated by R.W. Erney. The simulation runs fine, converges to stable low residuals (1e-5 - 1e-6), the domain itself I sufficiently large to assume free stream values, but the pressure field is nowhere near the correct values (high: 38.95, low: -48.64). After that I did another run without a turbulence model, but the pressure field did not change significantly (high: 37.31, low: -51.47). There must be something small and simple I'm overlooking, but for now I am completely stumped...

I included some additional sketches of my problem and provided a link to the complete case in a rar-file and a link to the thesis by R.W. Erney. Could somebody please take the time to look at my case and tell what error(s) this novice has made? You would totally make my week!

THESIS BY R.W. ERNEY

OPENFOAM CASE FILE