Dear community,
I have a problem with my simulation results. There are some solid areas who should be displayed in white as parts of the body of my CAD-geometry, but they are colored as it seems, there is a pressure zone in it.
Do you have an idea how to fix it?
Thank you very much
H Koeckemann
Hi @h_koeckemann and sorry for the delayed response.
Can you share your project please? @Get_Barried, @vgon_alves and I will have a look at it!
Best,
Jousef
Hi everyone,
This seems like a post-processing issue. Either that or the geometry is not watertight.
Will need the project link before we can conclude further.
Cheers.
Regards,
Barry
Hi Get_Barried,
Thank you for the reply. Unfortunately I can’t share the link to public. Do you have any idea, what the reason can be?
Mesh Operation:
Mesh Operation
Name
Operation 1
Tet-dominant
Hex-dominant automatic (only CFD)
Hex-dominant parametric (only CFD)
Hex-dominant automatic "wind-tunnel/external flow" (only CFD)
Hex-dominant (beta preview)
Properties
Bounding Box Discretization
Properties
Bounding Box geometry primitive
Background Mesh Box
Number of cells in x direction
105
Number of cells in y direction
30
Number of cells in z direction
30
Create multiregion mesh
Parallel Processing
Properties
Number of computing cores
Castellated mesh controls
Properties
Max number of cells per processor
40000000
Global max number of cells
100000000
Cell limit for refinement termination
10
Max processor load imbalance
0.2
Buffer cell count between refinement levels
2
Minimum angle for feature detection [°]
45
Allow free standing zone faces?
Snap controls
Properties
Mesh-to-geometry conformation iterations
10
Max relative distance for snap point search
2
Max iterations for meshing algorithm
150
Max iterations for removal of bad cells
15
Max iterations for mesh conformation
10
Implicitly detect features for snapping?
Use ‘feature refinement’ for snapping?
Detect features between multiple surfaces?
Layer adding controls
Properties
Use relative size for layers?
Max cancelled layers near sharp features
0
Max face angle for layer generation [°]
180
Min angle between patches for layers [°]
75
Max iterations for snapping of layers
10
Max smoothing iterations for surface normals
5
Max smoothing iterations for internal mesh
5
Max smoothing iterations for layer thickness
10
Max face aspect ratio for layers
0.55
Max ratio of layer thickness to medial length
0.35
Angle for medial axis points pick-up [°]
90
Buffer cells for faces where layers terminate
0
Max overall iterations for layer addition
10
Max iterations with strict quality controls
20
Mesh quality controls
Properties
Max non-orthogonality angle [°]
75
Max boundary face skewness angle [°]
20
Max internal face skewness angle [°]
4
Max concaveness [°]
80
Min cell volume [m³]
1e-13
Min tetrahedron-quality for cells
-1e+30
Min face area [m²]
-1
Min cosine of face twist
0.005
Min normalized cell determinant
0.005
Min face weight
0.01
Min volume ratio between neighbouring cells
0.0075
Min cosine of face twist between adjacent triangle faces
-1
Smoothing iterations for error distribution
4
Relative scale-back of erroneous points
0.75
Relaxed max non-orthogonality angle [°]
80
Merge tolerance
0.000001
Geometry Primitives
Background Mesh Box
Material Point
Cartesian Box-lower
Cartesian Box-upper
Mesh Refinements
alles-ausser-wings-susp-mountings
Wings
mountings-susp-bars
wheelhubs
Radiator
Feature
Region
Carlayer
Floor
MRFF
MRFR
Mesh Operation Event Log
The tesselated surface is not closed. There could be a problem with the CAD geometry (such as self-intersections). Please inspect your geometry. Trying to proceed anyway.
Mesh check finished.
Number of nodes: 17329610
Number of faces: 44896590
Number of volumes: 13899302
Number of tetrahedra: 61
Number of hexahedra: 11168513
Number of prisms: 457991
Number of pyramids: 25
Number of polyhedra: 2257761
Mesh quality check failed. The mesh is not OK.
Mesh import started.
Mesh bounding box diagonal length [m]: 29.632
Run finished.
Meshing log:
etected 64 illegal faces (concave, zero area or negative cell pyramid volume)
Extruding 2020584 out of 2150385 faces (93.9638250825%). Removed extrusion at 15 faces.
Added 5729913 out of 6451155 cells (88.8199554963%).
Edge intersection testing:
Number of edges : 44837883
Number of edges to retest : 0
Number of intersected edges : 7990584
patch faces layers overall thickness
[m] [%]
Layer mesh : cells:13899302 faces:44761114 points:17174003
Cells per refinement level:
0 102164
1 3992
2 15976
3 291366
4 115022
5 657587
6 2454706
7 5688374
8 4570115
Writing mesh to time constant
Wrote mesh in = 30.41 s.
Layers added in = 770.87 s.
Checking final mesh …
Checking faces in error :
non-orthogonality > 75 degrees : 17
faces with face pyramid volume < 1e-13 : 2
faces with concavity > 80 degrees : 0
faces with skewness > 4 (internal) or 20 (boundary) : 0
faces with interpolation weights (0…1) < 0.01 : 2
faces with volume ratio of neighbour cells < 0.0075 : 0
faces with face twist < 0.005 : 12
faces on cells with determinant < 0.005 : 30
Finished meshing with 63 illegal faces (concave, zero area or negative cell pyramid volume)
Finished meshing in = 786.03 s.
End
Finalising parallel run
Solver log:
Time = 1496
smoothSolver: Solving for Ux, Initial residual = 5.67164280367e-07, Final residual = 3.78196975668e-08, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 1.08001799891e-05, Final residual = 6.71079734362e-08, No Iterations 4
smoothSolver: Solving for Uz, Initial residual = 2.12374709298e-06, Final residual = 4.65392207358e-08, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000103034512166, Final residual = 6.53457120722e-07, No Iterations 5
time step continuity errors : sum local = 1.25350924225e-07, global = -2.56295681452e-11, cumulative = 4.42602031055e-06
smoothSolver: Solving for omega, Initial residual = 9.50647688777e-08, Final residual = 9.50647688777e-08, No Iterations 0
smoothSolver: Solving for k, Initial residual = 5.43877908366e-06, Final residual = 8.37109852932e-08, No Iterations 3
bounding k, min: -8.63000336714e-05 max: 606.541180354 average: 0.492576079293
ExecutionTime = 13561.89 s ClockTime = 13670 s
Time = 1497
smoothSolver: Solving for Ux, Initial residual = 5.63989809907e-07, Final residual = 3.73791757419e-08, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 1.07741723871e-05, Final residual = 6.71714399704e-08, No Iterations 4
smoothSolver: Solving for Uz, Initial residual = 2.11355999018e-06, Final residual = 4.59996552932e-08, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000102402757546, Final residual = 6.54378340425e-07, No Iterations 5
time step continuity errors : sum local = 1.25615680489e-07, global = -1.68849973615e-11, cumulative = 4.42600342555e-06
smoothSolver: Solving for omega, Initial residual = 9.57927142107e-08, Final residual = 9.57927142107e-08, No Iterations 0
smoothSolver: Solving for k, Initial residual = 5.54192358562e-06, Final residual = 8.31928548994e-08, No Iterations 3
bounding k, min: -1.27876199274e-06 max: 579.097977064 average: 0.492565773186
ExecutionTime = 13570.27 s ClockTime = 13679 s
Time = 1498
smoothSolver: Solving for Ux, Initial residual = 5.60974898508e-07, Final residual = 3.6987733183e-08, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 1.07398106269e-05, Final residual = 6.70341284214e-08, No Iterations 4
smoothSolver: Solving for Uz, Initial residual = 2.10575098695e-06, Final residual = 4.55214551237e-08, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000101915154281, Final residual = 6.63102939383e-07, No Iterations 5
time step continuity errors : sum local = 1.27287455967e-07, global = -1.91526074276e-11, cumulative = 4.42598427294e-06
smoothSolver: Solving for omega, Initial residual = 9.74527457422e-08, Final residual = 9.74527457422e-08, No Iterations 0
smoothSolver: Solving for k, Initial residual = 5.62868811717e-06, Final residual = 8.23727548016e-08, No Iterations 3
bounding k, min: -1.21660191662e-09 max: 543.572255049 average: 0.492553844143
ExecutionTime = 13578.59 s ClockTime = 13687 s
Time = 1499
smoothSolver: Solving for Ux, Initial residual = 5.58459661127e-07, Final residual = 3.66647155032e-08, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 1.07023872699e-05, Final residual = 6.68199526835e-08, No Iterations 4
smoothSolver: Solving for Uz, Initial residual = 2.09831350274e-06, Final residual = 4.52356394259e-08, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000101309647771, Final residual = 6.75010146034e-07, No Iterations 5
time step continuity errors : sum local = 1.29569907068e-07, global = -1.15065829809e-11, cumulative = 4.42597276636e-06
smoothSolver: Solving for omega, Initial residual = 9.87948090876e-08, Final residual = 9.87948090876e-08, No Iterations 0
smoothSolver: Solving for k, Initial residual = 5.65547600029e-06, Final residual = 8.14833660773e-08, No Iterations 3
bounding k, min: -4.67271715826e-10 max: 505.129320972 average: 0.492540893633
ExecutionTime = 13587.01 s ClockTime = 13696 s
Time = 1500
smoothSolver: Solving for Ux, Initial residual = 5.56315928233e-07, Final residual = 3.64339323244e-08, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 1.06820102417e-05, Final residual = 6.6550935528e-08, No Iterations 4
smoothSolver: Solving for Uz, Initial residual = 2.09153361617e-06, Final residual = 4.51266546477e-08, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000100819720241, Final residual = 6.76701422111e-07, No Iterations 5
time step continuity errors : sum local = 1.29891130914e-07, global = -5.29807248278e-13, cumulative = 4.42597223655e-06
smoothSolver: Solving for omega, Initial residual = 9.96790877793e-08, Final residual = 9.96790877793e-08, No Iterations 0
smoothSolver: Solving for k, Initial residual = 5.63053897064e-06, Final residual = 8.06414760131e-08, No Iterations 3
bounding k, min: -3.6159493063e-10 max: 468.38857153 average: 0.492527695947
ExecutionTime = 13606.2 s ClockTime = 13715 s
forces forces10 output:
sum of forces:
pressure : (16.83731687 -5.23650099772 -75.3859054792)
viscous : (0.643219139437 0.0409787985492 0.167810874721)
porous : (0 0 0)
sum of moments:
pressure : (-28.0536125765 -168.084778744 2.82252018976)
viscous : (0.0681925382546 0.428152288158 -0.372492258535)
porous : (0 0 0)
forces forces11 output:
sum of forces:
pressure : (26.7604585479 0.877284480112 -62.4629099665)
viscous : (0.561191748415 0.0220997454732 0.220243095105)
porous : (0 0 0)
sum of moments:
pressure : (-18.7864893153 34.6150349911 -8.4250955852)
viscous : (0.0532606853814 0.422300106025 -0.174417883282)
porous : (0 0 0)
forces forces12 output:
sum of forces:
pressure : (2.48190247263 0.583362761648 3.08619020252)
viscous : (0.145603176865 0.0156163476737 0.0611035885139)
porous : (0 0 0)
sum of moments:
pressure : (1.73063292932 5.30288338389 -2.39252171876)
viscous : (0.0308946711982 0.233308147405 -0.111872163528)
porous : (0 0 0)
forces forces13 output:
sum of forces:
pressure : (6.80108602039 -0.662133548905 3.50414365618)
viscous : (0.1393069617 -0.0286293709297 0.0712600245947)
porous : (0 0 0)
sum of moments:
pressure : (2.27434834799 1.5045137531 -3.83022094395)
viscous : (0.0483563124545 0.138261036992 -0.0820474980043)
porous : (0 0 0)
forces forces14 output:
sum of forces:
pressure : (0.68286234119 0.590216617059 0.14532491875)
viscous : (0.0473651128771 -0.00380437275155 0.00409362349078)
porous : (0 0 0)
sum of moments:
pressure : (-0.401963344907 0.452944872807 -0.166266258988)
viscous : (0.00336598394699 0.0332581370618 -0.00830937795046)
porous : (0 0 0)
forces forces15 output:
sum of forces:
pressure : (0.17494046503 0.241109742975 -0.118456331447)
viscous : (0.0162715592895 -0.000367317834061 0.00156070764689)
porous : (0 0 0)
sum of moments:
pressure : (-0.0745306566912 -0.233322093353 -0.613484042624)
viscous : (0.000499716762315 0.00654000854068 -0.00207594728564)
porous : (0 0 0)
forces forces16 output:
sum of forces:
pressure : (10.0785607108 -20.8925948093 -3.8587874758)
viscous : (0.571802334846 0.079262500095 0.00596844098667)
porous : (0 0 0)
sum of moments:
pressure : (5.18954585476 -2.85170041248 32.8431262735)
viscous : (-0.0290464134697 0.164490121412 -0.199721803909)
porous : (0 0 0)
forces forces17 output:
sum of forces:
pressure : (77.3097121915 -23.0312438011 -132.815208273)
viscous : (2.372171628 0.141237729494 0.570953725386)
porous : (0 0 0)
sum of moments:
pressure : (-37.6788893154 -121.140791531 16.934128302)
viscous : (0.169748105622 1.5438244479 -1.03775407159)
porous : (0 0 0)
End
Finalising parallel run
I can give you all details of our setup, just tell me what you need to know.
Thank you very much
H Koeckemann
Hi @h_koeckemann,
Apologies for the serve delay in reply. Was quite caught up the past few days.
Firstly, thank you for posting as much information as you can. I understand the need to keep a project private, but it will take significantly longer to arrive at a solution as you should expect.
As mention the issue looks like a post-processing issue or a geometry issue. Can you check the initial geometry under the meshing tab to see if it says it is watertight? If it is a STL format then it will not be possible to perform this check and we will need to move on to the mesher itself.
For meshing, do ensure that the material point does not intersect the geometry at all and is instead in free space but within the computational domain. The material point allows the solver to determine internal and external flow so it is important to pay attention to where it is located.
Post-processing wise, I suggest downloading the results into ParaView and loading in the geometry before doing your data slices. Do ensure that all parts of the geometry are ticked and loaded with the exception of the bounding box as it will obstruct your view. There are tutorials online on how to perform this relatively simple procedure.
Let me know if you have any other problems.
Cheers.
Regards,
Barry