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April 7, 2007, 10:15 
Hi,
I am running rasInterFo

#1 
Senior Member

Hi,
I am running rasInterFoam for a freesurface piercing NACA 0024 hydrofoil at Fr = 0.55. Overall, the solution looks quite good with nice resolution of the bow wave, the wave profile, and the spilling breaking wave. So, what's the issue? I've run both coarse (~0.3M cells) and fine (~2M cells) hex meshes, and have some nonphysical small amplitude waves in the gamma field which are seen on the gamma=0.5 isosurface (i.e., the free surface). Anyone have suggestions on fvSchemes settings to eliminate this problem? I am using standard rasInterFoam settings, // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes { default Euler; } gradSchemes { default Gauss linear; } divSchemes { div(rho*phi,U) Gauss upwind; div(phi,gamma) Gauss limitedLinear01 1; div(phirb,gamma) Gauss limitedLinear01 1; div(phi,k) Gauss upwind; div(phi,epsilon) Gauss upwind; div(phi,R) Gauss upwind; div(R) Gauss linear; div(phi,nuTilda) Gauss upwind; } laplacianSchemes { default Gauss linear corrected; } interpolationSchemes { default linear; interpolate(HbyA) linear; } snGradSchemes { default corrected; } fluxRequired { default no; pd; pcorr; gamma; } // ************************************************** *********************** // To get an idea of what I am seeing, I've put a couple of animations (naca0024...) for download at: http://homepage.mac.com/egpaterson/FileSharing2.html Thanks, Eric 

April 8, 2007, 18:18 
Try:
div(phi,gamma) Gaus

#2 
Senior Member
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,806
Rep Power: 25 
Try:
div(phi,gamma) Gauss Gamma01 1; div(phirb,gamma) Gauss Gamma01 1; Hrv
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Hrvoje Jasak Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk 

April 9, 2007, 19:02 
Hrv,
I tried the Gamma01 sc

#3 
Senior Member

Hrv,
I tried the Gamma01 scheme, although I did restart from the exisiting solution. However, it had no noticable impact. We'll have to do some more digging to understand this better. Eric 

April 11, 2007, 03:13 
Hi Eric
I have had the same

#4 
New Member
Joakim Möller
Join Date: Mar 2009
Posts: 26
Rep Power: 10 
Hi Eric
I have had the same problems using interFoam. The only way I have found to eliminate the overshoots is to use div(rho*phi,U) Gauss upwind; div(phi,gamma) Gauss upwind; Regards /Joakim 

April 12, 2007, 11:02 
Hi Joakim,
Thanks, as you c

#5 
Senior Member

Hi Joakim,
Thanks, as you can see from the image which compares upwind vs. limitedLinear01 on gamma , the upwind scheme took care of the problem as would be expected with a first order scheme. However, it also smoothed the diverging wave in the wake. I'm going to test out the other TVD schemes. Eric 

May 1, 2007, 16:26 
Hello,
I am continuing to w

#7 
Guest
Posts: n/a

Hello,
I am continuing to work on this case. I would like to get a 2ndorder scheme working without the nonphysical waves that were smoothed out by upwind. Currently I am working with rasInterFoam, FR=0.55, coarse (~246,000 cell) grid. This is the same case Eric posted about above, all is the same except my fvSchemes dict which is below: // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes { default Euler; } gradSchemes { default Gauss linear; } divSchemes { div(rho*phi,U) Gauss MUSCL; div(phi,gamma) Gauss MUSCL; div(phirb,gamma) Gauss MUSCL; div(phi,k) Gauss upwind; div(phi,epsilon) Gauss upwind; div(phi,R) Gauss upwind; div(R) Gauss linear; div(phi,nuTilda) Gauss upwind; } laplacianSchemes { default Gauss linear corrected; } interpolationSchemes { default linear; interpolate(HbyA) MUSCL; } snGradSchemes { default corrected; } fluxRequired { default no; pd; pcorr; gamma; } // ************************************************** *********************** // Has anyone had any experience/problems implementing MUSCL? I've run the following to attempt to get the solution started: (1) water/air density ratio: 1000:100 CFL=0.1 ran OK for 75 time steps (2) 1000:10 CFL=0.1 Did not work in that pcorr iterations were >5000 and/or deltaT was less than 1e33 or CFL greater than 1.0 (3) changed to CFL=0.05, 0.04, 0.03 crashed in a similar manner (4) changed the water/air density ratio to 1000:100 again and CFL=0.1: Runs OK! (5) changed density ratio to 1000:50 CFL=0.1 runs OK (6) changed density ratio to 1000:1 CFL=0.1, 0.05, 0.025, 0.0125, 0.00625 crashed as above My next thought is to try ratio of 1000:10. Any thoughts/comments/suggestions would be greatly appreciated. Thank you, Ryan Carley 

May 2, 2007, 08:49 
Have you tried OF1.4 with the

#8 
Senior Member
Eugene de Villiers
Join Date: Mar 2009
Posts: 725
Rep Power: 14 
Have you tried OF1.4 with the MULES scheme for gamma yet?
You categorically cannot run Gamma with a scheme that is not strictly bounded between 0 and 1, e.g. MULES or gamma01 

May 2, 2007, 08:59 
Belay that, just check the OF1

#9 
Senior Member
Eugene de Villiers
Join Date: Mar 2009
Posts: 725
Rep Power: 14 
Belay that, just check the OF1.4 tutorials for what schemes to use on gamma.


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