OpenFoam, SALOME, all free tools for engineers
-
blockMesh,snappyMesh and experimental results for 2D airfoil
Quote:No matter how big your AR is. This way to build meshes with o-grid block works fine also in case of thin compressor blades.
I will look for sHM - files. I just wanna to say reduce nLayers and increase minMedianAxisAngle and featureAngle. Your empty patches should be "patches" when you generating coarse and snapped mesh. You should switch to "empty" only when generating layers.
Any other settings you could see here http://openfoamwiki.net/images/f/f0/...SlidesOFW7.pdfPosted December 10, 2020 at 04:40 by aglios900 -
blockMesh,snappyMesh and experimental results for 2D airfoil
Quote:Thank you skeptik! I considered your idea but my ellipse has an aspect ratio equal to 2% (try to plot it and you will understand me), so this is the reason why I decided emulate your O-grid and mesh it by using sHM and adding some layers... So, could you share again your files, please??
Thank you very much!!
All the best.
I will look for sHM - files. I just wanna to say reduce nLayers and increase minMedianAxisAngle and featureAngle. Your empty patches should be "patches" when you generating coarse and snapped mesh. You should switch to "empty" only when generating layers.
Any other settings you could see here http://openfoamwiki.net/images/f/f0/...SlidesOFW7.pdfPosted April 25, 2014 at 08:56 by skeptik -
blockMesh,snappyMesh and experimental results for 2D airfoil
Thank you skeptik! I considered your idea but my ellipse has an aspect ratio equal to 2% (try to plot it and you will understand me), so this is the reason why I decided emulate your O-grid and mesh it by using sHM and adding some layers... So, could you share again your files, please??
Thank you very much!!
All the best.Posted April 25, 2014 at 08:36 by maalan -
blockMesh,snappyMesh and experimental results for 2D airfoil
Quote:My original mesh is a circular cylinder within an O-grid domain. Once applied the Joukowski transformation I get an ellipse within an O-grid conformal mesh. Have a look here, skeptik!!
https://www.dropbox.com/s/lp2mbo0sz2jblgt/ellipse.pdf
https://www.dropbox.com/s/jgmjbbv9mlvormu/ellipse2.pdf
https://www.dropbox.com/s/owr757rkbwi386m/ellipse3.pdf
Just make the o-grid blocks with elliptical edges with attention to edge-to-egde distance and you will have a good mesh to resolve BL.
https://www.dropbox.com/s/slsu1ek052z011c/ellipse.png
Posted April 25, 2014 at 07:29 by skeptik -
blockMesh,snappyMesh and experimental results for 2D airfoil
My original mesh is a circular cylinder within an O-grid domain. Once applied the Joukowski transformation I get an ellipse within an O-grid conformal mesh. Have a look here, skeptik!!
https://www.dropbox.com/s/lp2mbo0sz2jblgt/ellipse.pdf
https://www.dropbox.com/s/jgmjbbv9mlvormu/ellipse2.pdf
https://www.dropbox.com/s/owr757rkbwi386m/ellipse3.pdfPosted April 24, 2014 at 14:41 by maalan -
blockMesh,snappyMesh and experimental results for 2D airfoil
Quote:Thanks for your reply, skeptik!! I know what you mean, and up to the moment I tried successfully a conformal mesh from a cylinder mesh (I applied the Joukowski transformation). The point is that my ellipse has 2% aspect ratio, so, assuming the major axis of my ellipse is aligned with the x-axis and the minor axis with the y-axis, i get very thin cells normal to the wall both in the trailing and leading edges and much coarser cells normal to the wall in the middle of my ellips. I'm afraid that my viscous term will not be well solved... What do you think of?? any idea??
Best!Posted April 24, 2014 at 14:19 by skeptik -
blockMesh,snappyMesh and experimental results for 2D airfoil
Thanks for your reply, skeptik!! I know what you mean, and up to the moment I tried successfully a conformal mesh from a cylinder mesh (I applied the Joukowski transformation). The point is that my ellipse has 2% aspect ratio, so, assuming the major axis of my ellipse is aligned with the x-axis and the minor axis with the y-axis, i get very thin cells normal to the wall both in the trailing and leading edges and much coarser cells normal to the wall in the middle of my ellips. I'm afraid that my viscous term will not be well solved... What do you think of?? any idea??
Best!Posted April 24, 2014 at 13:56 by maalan -
blockMesh,snappyMesh and experimental results for 2D airfoil
Quote:Hi skeptik!
I'm currently trying to simulate the flow over a high aspect ratio ellipse but i am very new with snappyHexMesh and blockMesh. I always imported my meshes from gambit...
would you mind to repost the snappyhexMeshDict and blockMeshDict you used for this case? The link is no longer available...
Thanks in advance!
Best!
But, ellipse is an analytical surface. You really don't need a sHM utility to build a mesh. Try blockMesh!Posted April 24, 2014 at 13:27 by skeptik -
blockMesh,snappyMesh and experimental results for 2D airfoil
Hi skeptik!
I'm currently trying to simulate the flow over a high aspect ratio ellipse but i am very new with snappyHexMesh and blockMesh. I always imported my meshes from gambit...
would you mind to repost the snappyhexMeshDict and blockMeshDict you used for this case? The link is no longer available...
Thanks in advance!
Best!Posted April 24, 2014 at 09:24 by maalan -
God bless America
Quote:Hi skeptik,
Nice! The courses they have got, also come in handy... so I've added the links for them here: http://openfoamwiki.net/index.php/Ha...ourse-training
And I think the title for this blog post should be "God bless America and Italy"
Best regards,
BrunoPosted December 9, 2013 at 03:18 by skeptik -
God bless America
Hi skeptik,
Nice! The courses they have got, also come in handy... so I've added the links for them here: http://openfoamwiki.net/index.php/Ha...ourse-training
And I think the title for this blog post should be "God bless America and Italy"
Best regards,
BrunoPosted December 8, 2013 at 16:45 by wyldckat -
Posted November 27, 2013 at 01:10 by skeptik -
Loosing precision with symmetryPlane
Have you had data for slip BC now?Posted November 25, 2013 at 23:35 by lixx -
Posted November 16, 2013 at 17:07 by skeptik -
Good news about airfoil and OpenFoam
Hi Ilya,
Do You have any experience with airfoil LES and Fv schemes and Fv solutions for Airfoil LES
Thanks,
Hasan K.JPosted November 15, 2013 at 14:44 by Alhasan -
Useful article about mesh types
Thank you. Very nice!Posted October 17, 2013 at 09:50 by styleworker -
blockMesh,snappyMesh and experimental results for 2D airfoil
Archive with case files is here
https://www.dropbox.com/s/1ih182x44v...appyHex.tar.gz
There are both snappyHex case and 2Dextrusion case with extrusion dictionary. In the one of this case resulted mesh was saved and archived.
Enjoy.Posted April 18, 2013 at 04:13 by skeptik -
blockMesh,snappyMesh and experimental results for 2D airfoil
Quote:Posted April 18, 2013 at 02:23 by skeptik -
blockMesh,snappyMesh and experimental results for 2D airfoil
Hi skeptik!
I'm currently doing some simulations of flow over airfoils, but i have some trouble getting a nice mesh with snappyHexMesh...
could you please send me your snappyhexMeshDict you used for this case, cause the mesh looks very nice!
Thank you in advance
ArminPosted April 17, 2013 at 14:05 by arming -
Good news about airfoil and OpenFoam
Quote:ok I understand ....... I am sumulating the flow over naca23012 and it is a pain in the ass getting the the solution to converge......I am using wall functions and a High Re 3*e06........I am interested to know about you fvschemes and fvsolutions that you used...
I will appreciate that.
Many thanks
If you have coarse mesh, the convergence could be really bad.
In addition fvSchemes and fvSolutions
Code:ddtSchemes { default steadyState; } gradSchemes { default Gauss linear; grad(p) Gauss linear; //grad(U) Gauss linear; grad(U) cellLimited Gauss linear 1; } divSchemes { default none; // div(phi,U) Gauss upwind; div(phi,U) Gauss linearUpwindV Gauss linear; div(phi,k) Gauss upwind; div(phi,epsilon) Gauss upwind; div(phi,R) Gauss upwind; div(R) Gauss linear; div(phi,nuTilda) Gauss upwind; div((nuEff*dev(grad(U).T()))) Gauss linear; } laplacianSchemes { default Gauss linear limited 0.5; //none; /* laplacian(nuEff,U) Gauss linear corrected; laplacian((1|A(U)),p) Gauss linear corrected; laplacian(DkEff,k) Gauss linear corrected; laplacian(DepsilonEff,epsilon) Gauss linear corrected; laplacian(DREff,R) Gauss linear corrected; laplacian(DnuTildaEff,nuTilda) Gauss linear corrected;*/ } interpolationSchemes { default linear; interpolate(U) linear; } snGradSchemes { default corrected; } fluxRequired { default no; p ; }
Code:solvers { p { solver GAMG; tolerance 1e-7; relTol 0.1; smoother GaussSeidel; nPreSweeps 0; nPostSweeps 2; cacheAgglomeration on; agglomerator faceAreaPair; nCellsInCoarsestLevel 10; mergeLevels 1; }; U { solver smoothSolver; smoother GaussSeidel; tolerance 1e-8; relTol 0.1; nSweeps 1; }; k { solver smoothSolver; smoother GaussSeidel; tolerance 1e-8; relTol 0.1; nSweeps 1; maxIter 100; minIter 1; }; epsilon { solver smoothSolver; smoother GaussSeidel; tolerance 1e-8; relTol 0.1; nSweeps 1; maxIter 100; minIter 1; } R { solver smoothSolver; smoother GaussSeidel; tolerance 1e-8; relTol 0.1; nSweeps 1; maxIter 100; minIter 1; } nuTilda { solver smoothSolver; smoother GaussSeidel; tolerance 1e-8; relTol 0.1; nSweeps 1; maxIter 100; minIter 1; } } SIMPLE { nNonOrthogonalCorrectors 4; pRefCell 0; pRefValue 0; residualControl { p 1e-5; U 1e-5; "(k|omega)" 1e-5; } } relaxationFactors { p 0.3; U 0.5; k 0.7; epsilon 0.7; R 0.7; nuTilda 0.7; }
Posted March 21, 2013 at 06:03 by skeptik