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#1 |
Member
Join Date: Aug 2011
Posts: 33
Rep Power: 15 ![]() |
Dear Foamers,
I am struggling with a Problem for several weeks already and starting to get really desperate. I have posted it in the main forum already, but I figured posting a new thread here as I have narrowed the problem down to blockMesh, I guess so at least. The Problem is I want to simulate a thin layer with a bump, I have modelled the bump with a blockMeshDict. What is wrong here is that the volume is not recognized correctly. You can see in checkMesh the total volume of 1256.62. But this cannot be correct, since a flat disc with height one and radius 20 would have exactly that volume (Pi*r^2) But the graphical output in paraview is correct. Whats wrong here? ![]() Now when I do checkMesh, this is the output Code:
/*---------------------------------------------------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.0.0 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ Build : 2.0.0-a317a4e7cd55 Exec : checkMesh Date : Jan 29 2012 Time : 15:48:06 Host : ernie PID : 7269 Case : /home/boie/OpenFOAM/OpenFOAM-reloaded/boie-2.0.0/simulations/tests/justbump nProcs : 1 sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE). fileModificationChecking : Monitoring run-time modified files using timeStampMaster allowSystemOperations : Disallowing user-supplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create polyMesh for time = 0 Time = 0 Mesh stats points: 80802 internal points: 0 faces: 160400 internal faces: 79600 cells: 40000 boundary patches: 3 point zones: 0 face zones: 0 cell zones: 0 Overall number of cells of each type: hexahedra: 40000 prisms: 0 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 0 polyhedra: 0 Checking topology... Boundary definition OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces ... Patch Faces Points Surface topology frontWall 40000 40401 ok (non-closed singly connected) backWall 40000 40401 ok (non-closed singly connected) circular 800 1600 ok (non-closed singly connected) Checking geometry... Overall domain bounding box (-20 -20 -0.0312941) (20 20 21) Mesh (non-empty, non-wedge) directions (1 1 1) Mesh (non-empty) directions (1 1 1) Boundary openness (8.25305e-21 7.15265e-20 -3.39808e-19) OK. Max cell openness = 2.24782e-16 OK. Max aspect ratio = 321.104 OK. Minumum face area = 0.000702619. Maximum face area = 0.283752. Face area magnitudes OK. Min volume = 0.000692074. Max volume = 0.0803204. Total volume = 1256.62. Cell volumes OK. Mesh non-orthogonality Max: 87.5911 average: 38.3172 *Number of severely non-orthogonal faces: 624. Non-orthogonality check OK. <<Writing 624 non-orthogonal faces to set nonOrthoFaces Face pyramids OK. Max skewness = 2.81207 OK. Mesh OK. End |
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#2 |
Senior Member
BastiL
Join Date: Mar 2009
Posts: 530
Rep Power: 20 ![]() |
I don't see you problem. Your formula is right and I get:
3.14*20^2=3.14*400=1256. So for me everything seems to be fine. |
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#3 |
Member
Join Date: Aug 2011
Posts: 33
Rep Power: 15 ![]() |
Hi bastil,
well the problem is the volume must be larger than this. See the attached picture, its a bump and not a disc anymore. The Problem is similiar to taking a cube and a cube with a large dent in it but with the same length of the edges. The volume should be different |
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#4 | |
Member
Join Date: Aug 2011
Posts: 33
Rep Power: 15 ![]() |
To illustrate my problem I have made 2 more screenshots. In the first picture you look from on top on the geometry.
In the second picture is the same geometry with a different angle of observation. checkMesh reports no errors and a total volume of: Quote:
On the second picture you see the real geometry and clearly the volume must be larger... I really have no idea what is going wrong here ![]() |
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