| nuovodna |
June 9, 2010 12:49 |
Stangind Wave case - Completely different results between Structured and Unstructured
Hi, i have a standing wave case (box 1x1x1), velocity max value : 0.04, nu_water/nu_air = 10, Re=1060. I have to different mesh.
1) Structured mesh: generated by blockMesh 100x100x1
The cinetic energy plot is not like what i would but it's similar
http://dl.dropbox.com/u/3617688/Structured.png
2) Unstructured Mesh: made with gmsh
CheckMesh output:
Code:
Create polyMesh for time = 0
Time = 0
Mesh stats
points: 10296
internal points: 0
faces: 35237
internal faces: 14913
cells: 10030
boundary patches: 5
point zones: 0
face zones: 0
cell zones: 1
Overall number of cells of each type:
hexahedra: 0
prisms: 10030
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
patch0 66 134 ok (non-closed singly connected)
patch1 66 134 ok (non-closed singly connected)
patch2 66 134 ok (non-closed singly connected)
patch3 66 134 ok (non-closed singly connected)
defaultFaces 20060 10296 ok (non-closed singly connected)
Checking geometry...
Overall domain bounding box (0 -0.5 0) (1 0.5 1)
Mesh (non-empty, non-wedge) directions (1 1 0)
Mesh (non-empty) directions (1 1 0)
All edges aligned with or perpendicular to non-empty directions.
Boundary openness (-7.86408e-17 6.4763e-17 0) OK.
Max cell openness = 1.2645e-16 OK.
Max aspect ratio = 317.061 OK.
Minumum face area = 4.71827e-05. Maximum face area = 0.0212115. Face area magnitudes OK.
Min volume = 4.71827e-05. Max volume = 0.000180794. Total volume = 1. Cell volumes OK.
Mesh non-orthogonality Max: 30.3678 average: 6.4204
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 0.492019 OK.
Mesh OK.
End
completely different solution. It produce cinetic energy instead of vanishing
http://dl.dropbox.com/u/3617688/unsVsStru.png
The system/constant files are the same except for this part of fvScheme file
Code:
PISO
{
momentumPredictor no;
nCorrectors 3;
nNonOrthogonalCorrectors 3;
nAlphaCorr 1;
nAlphaSubCycles 2;
cAlpha 1;
}
Any idea how can i solve this issue?? |
