[AndreP]

Hello Guys,

I'm trying to mesh a full F1 car, and because my previous CFD simulations were much simpler geometries (I used Regions Based Mesh), this is my first time using Parts Based Mesh.

For a starting point on the mesh, I'm using Surface Wrapper and Automated Mesh (Surface Remesher, Trimmed, Prism Layer) (following some tutorials my supervisor gave me), but it's not being able to mesh:

And this is the error I'm having:
"
----------------------------------------
Surface Remesher Completed: CPU Time: 3053.02, Wall Time: 3056.30, Memory: 18957.27 MB
----------------------------------------
Following Parts are Self Intersecting
Surface Wrapper
Command: GenerateVolumeMesh
error: Server Error
Following Parts are Self Intersecting
Surface Wrapper
Command: GenerateVolumeMesh
command: CommandComplete
error: Server Error

Design STAR-CCM+ simulation completed
Server process exited with code : 0"

I can't really identify what can be causing this. Can anyone give me some hints where I can look for problems causing this?

If anyone fancies having a look here it is the file: (Keep in mind you won't be able to run this on a PC, only on cluster, as it's taking 2 hours on a cluster to get to the volume mesh!)

https://drive.google.com/file/d/1Pd8...ew?usp=sharing

Thank you

[AndreP]

In case it helps anyone, here is the complete slurm file!

Starting local server: /system/software/generic/brookes/CD-adapco/12.04.010-R8/STAR-CCM+12.04.010-R8/star/bin/starccm+ -mpi intel -np 16 -machinefile hostfile.txt -mppflags "-bootstrap slurm" -server -rsh ssh Perrinn_Benchmark.sim
Starting STAR-CCM+ parallel server
MPI Distribution : Intel MPI-5.0.3
Host 0 -- cnode2079 -- Ranks 0-15
Process rank 0 cnode2079 3110
Total number of processes : 16

STAR-CCM+ 12.04.010 (linux-x86_64-2.5/gnu4.8-r8)
License build date: 02 February 2017
This version of the code requires license version 2017.06 or greater.
Checking license file: 27000@10.4.144.10
1 copy of ccmpsuite checked out from 27000@10.4.144.10
Feature ccmpsuite expires in 74 days
Thu Jul 19 11:59:19 2018

Server::start -host cnode2079.arcus.arc.local:47827
Loading object database: Perrinn_Benchmark.sim
Loading module: StarMeshing
Loading module: MeshingSurfaceRepair
Loading module: StarSurfaceWrapper
Loading module: StarResurfacer
Loading module: StarTrimmer
Loading module: SegregatedFlowModel
Loading module: KeTurbModel
Simulation database saved by:
STAR-CCM+ 12.04.010 (win64/intel16.3-r8) Tue Jun 6 18:28:42 UTC 2017 Serial
Loading into:
STAR-CCM+ 12.04.010 (linux-x86_64-2.5/gnu4.8-r8) Tue Jun 6 18:28:42 UTC 2017 Np=16
Started Parasolid modeler version 29.01.131
Object database load completed.
Generating mesh
Executing parts-based mesh operations
----------------------------------------
Executing Automated Mesh Operation: Surface Wrapper
----------------------------------------
Projecting to CAD geometry where possible
----------------------------------------
Executing Surface Wrapper
----------------------------------------

Checking input surface validity
done, CPU Time: 0.15, Memory: 1665.66 MB, # Trias: 2960942

Computing Entity Depth
computing surface proximity
min:max face size 0.0005:0.2
done, CPU Time: 113.98, Memory: 1965.88 MB, # Trias: 2960942

Generating Octree Mesh
Estimated size of initial output surface: 35121587
done, CPU Time: 104.87, Memory: 5469.30 MB

Obtaining Initial Surface
created 29501160 triangles
done, CPU Time: 37.94, Memory: 7504.70 MB, # Trias: 29501160

Fixing Non-manifold Surface
done, CPU Time: 22.04, Memory: 9047.18 MB, # Trias: 29501324

Constraining Vertices to Input Surface
constraining 14750420 vertices to original surface
done, CPU Time: 62.82, Memory: 9159.71 MB, # Trias: 29501324

Improving Triangle Quality
done, CPU Time: 23.24, Memory: 9082.70 MB, # Trias: 29110294

Marking flipped faces
done, CPU Time: 18.36, Memory: 9206.54 MB, # Trias: 29109238

Defining Features
Initializing data structures
Retaining Features (1/4)
Retaining Features (2/4)
Retaining Features (3/4)
Defeaturing (4/4)
done, CPU Time: 482.23, Memory: 9206.54 MB, # Trias: 29335158

Imprinting Features
built 1345 chains of feature edges for imprinting
done, CPU Time: 22.91, Memory: 9206.54 MB, # Trias: 29404128

Fixing Baffles
found 114 final baffle faces
done, CPU Time: 46.68, Memory: 9206.54 MB, # Trias: 29383096

Assigning Face Types to Surface
done, CPU Time: 851.12, Memory: 9206.54 MB

Reassociating wrapped mesh with CAD

Non-manifold wrap edge to CAD edge mapping for CAD edge 12958 at wrap mesh vertex 3820056
done, CPU Time: 1135.12, Memory: 9206.54 MB

Fixing flipped faces
done, CPU Time: 35.56, Memory: 9544.16 MB, # Trias: 29311460

Checking for intersections
Fixing Intersections
done, CPU Time: 225.99, Memory: 9686.33 MB, # Trias: 29310720


Final surface wrap statistics:
29310720 final surface triangles
216083 special edges
0 special vertices
114 baffle faces inflated automatically
0 intersecting edges remain
0 pierced faces remain
100% of input vertices on CAD(1480549/1480549)
100% of input faces on CAD(2960942/2960942)
99.8884% of output vertices on CAD(14638772/14655128)
99.8189% of output faces on CAD(29257631/29310720)

----------------------------------------
Surface Wrapper Completed: CPU Time: 3422.77, Wall Time: 3426.29, Memory: 8643.90 MB
----------------------------------------
----------------------------------------
Automated Mesh Operation: Surface Wrapper complete. CPU Time: 3428.45, Wall Time: 3432.82, Memory: 8610.00 MB
----------------------------------------
----------------------------------------
Executing Automated Mesh Operation: Automated Mesh
----------------------------------------
Checking mesh-CAD association...
done. Found 121 problems, all fixed.
----------------------------------------
Preparing surface for surface meshing in Parts:
----------------------------------------

----------------------------------------
finished preparing surface for surface meshing CPU Time: 28.85, Wall Time: 28.92, Memory: 11064.10 MB
----------------------------------------
Projecting to CAD geometry
----------------------------------------
Executing Surface Remesher
----------------------------------------

Face Quality Faces Percent
< 0.001 21 0.0
< 0.01 464 0.0
< 0.05 1764 0.0
< 0.1 2863 0.0
< 0.2 306635 1.0
< 0.3 644209 2.2
< 0.4 1051100 3.6
< 0.5 1662626 5.7
< 0.6 2693155 9.2
< 0.7 4800317 16.4
< 0.8 8865084 30.2
< 0.9 26319407 89.8
< 1.0 29310714 100.0
Worst quality is 8.262e-06
initial number of faces: 29310714

starting: Apply Global Limits
current number of faces: 29200000
current number of faces: 29100000
current number of faces: 29000000
current number of faces: 28900000
current number of faces: 28800000
current number of faces: 28700000
current number of faces: 28600000
current number of faces: 28500000
current number of faces: 28400000
current number of faces: 28300000
current number of faces: 28200000
current number of faces: 28100000
current number of faces: 28000000
current number of faces: 27900000
current number of faces: 27800000
current number of faces: 27700000
current number of faces: 27600000
current number of faces: 27500000
current number of faces: 27400000
current number of faces: 27300000
current number of faces: 27200000
current number of faces: 27100000
current number of faces: 27000000
current number of faces: 26900000
current number of faces: 26800000
current number of faces: 26700000
current number of faces: 26600000
current number of faces: 26500000
current number of faces: 26400000
current number of faces: 26300000
current number of faces: 26200000
current number of faces: 26100000
current number of faces: 26000000
current number of faces: 25900000
current number of faces: 25800000
current number of faces: 25700000
current number of faces: 25600000
current number of faces: 25500000
current number of faces: 25400000
current number of faces: 25300000
current number of faces: 25200000
current number of faces: 25100000
current number of faces: 25000000
current number of faces: 24900000
current number of faces: 24800000
current number of faces: 24700000
current number of faces: 24600000
current number of faces: 24500000
current number of faces: 24400000
current number of faces: 24300000
current number of faces: 24200000
current number of faces: 24100000
current number of faces: 24000000
current number of faces: 23900000
current number of faces: 23800000
current number of faces: 23700000
current number of faces: 23600000
current number of faces: 23500000
current number of faces: 23400000
current number of faces: 23300000
current number of faces: 23200000
current number of faces: 23100000
current number of faces: 23000000
current number of faces: 22900000
current number of faces: 22800000
current number of faces: 22700000
current number of faces: 22600000
current number of faces: 22500000
current number of faces: 22400000
current number of faces: 22300000

Face Quality Faces Percent
< 0.001 172 0.0
< 0.01 529 0.0
< 0.05 1435 0.0
< 0.1 2245 0.0
< 0.2 28805 0.1
< 0.3 73070 0.3
< 0.4 146684 0.7
< 0.5 272150 1.2
< 0.6 502080 2.3
< 0.7 1195178 5.4
< 0.8 3914575 17.6
< 0.9 19105801 86.0
< 1.0 22208572 100.0
Worst quality is 0

starting: Improve Grading
current number of faces: 22200000
current number of faces: 22100000
current number of faces: 22000000
current number of faces: 21900000
current number of faces: 21800000
current number of faces: 21700000
current number of faces: 21600000
current number of faces: 21500000
current number of faces: 21400000
current number of faces: 21300000
current number of faces: 21200000
current number of faces: 21100000
current number of faces: 21000000
current number of faces: 20900000
current number of faces: 20800000
current number of faces: 20700000
current number of faces: 20600000
current number of faces: 20500000
current number of faces: 20400000
current number of faces: 20300000
current number of faces: 20200000
current number of faces: 20100000
current number of faces: 20000000
current number of faces: 19900000
current number of faces: 19800000
current number of faces: 19700000
current number of faces: 19600000
current number of faces: 19500000
current number of faces: 19400000
current number of faces: 19300000
current number of faces: 19200000
current number of faces: 19100000
current number of faces: 19000000
current number of faces: 18900000
current number of faces: 18800000
current number of faces: 18700000
current number of faces: 18600000
current number of faces: 18500000
current number of faces: 18400000
current number of faces: 18300000
current number of faces: 18200000
current number of faces: 18100000
current number of faces: 18000000
current number of faces: 17900000
current number of faces: 17800000
current number of faces: 17700000
current number of faces: 17600000
current number of faces: 17500000
current number of faces: 17400000
current number of faces: 17300000
current number of faces: 17200000
current number of faces: 17100000
current number of faces: 17000000
current number of faces: 16900000
current number of faces: 16800000
current number of faces: 16700000
current number of faces: 16600000
current number of faces: 16500000
current number of faces: 16400000
current number of faces: 16300000
current number of faces: 16200000
current number of faces: 16100000
current number of faces: 16000000
current number of faces: 15900000
current number of faces: 15800000
current number of faces: 15700000
current number of faces: 15600000
current number of faces: 15500000
current number of faces: 15400000
current number of faces: 15300000
current number of faces: 15200000
current number of faces: 15100000
current number of faces: 15000000
current number of faces: 14900000
current number of faces: 14800000
current number of faces: 14700000
current number of faces: 14600000
current number of faces: 14500000
current number of faces: 14400000
current number of faces: 14300000
current number of faces: 14200000
current number of faces: 14100000
current number of faces: 14000000
current number of faces: 13900000
current number of faces: 13800000
current number of faces: 13700000
current number of faces: 13600000
current number of faces: 13500000
current number of faces: 13400000
current number of faces: 13300000
current number of faces: 13200000
current number of faces: 13100000
current number of faces: 13000000
current number of faces: 12900000
current number of faces: 12800000
current number of faces: 12700000
current number of faces: 12600000
current number of faces: 12500000
current number of faces: 12400000
current number of faces: 12300000
current number of faces: 12200000
current number of faces: 12100000
current number of faces: 12000000
current number of faces: 11900000
current number of faces: 11800000
current number of faces: 11700000
current number of faces: 11600000
current number of faces: 11500000
current number of faces: 11400000
current number of faces: 11300000
current number of faces: 11200000
current number of faces: 11100000
current number of faces: 11000000
current number of faces: 10900000
current number of faces: 10800000
current number of faces: 10700000
current number of faces: 10600000
current number of faces: 10500000
current number of faces: 10400000
current number of faces: 10300000
current number of faces: 10200000
current number of faces: 10100000
current number of faces: 10000000
current number of faces: 9900000
current number of faces: 9800000
current number of faces: 9700000
current number of faces: 9600000
current number of faces: 9500000
current number of faces: 9400000
current number of faces: 9300000
current number of faces: 9200000
current number of faces: 9100000
current number of faces: 9000000
current number of faces: 8900000
current number of faces: 8800000
current number of faces: 8700000
current number of faces: 8600000
current number of faces: 8500000
current number of faces: 8400000
current number of faces: 8300000
current number of faces: 8200000
current number of faces: 8100000
current number of faces: 8000000
current number of faces: 7900000
current number of faces: 7800000
current number of faces: 7700000
current number of faces: 7600000
current number of faces: 7500000
current number of faces: 7400000
current number of faces: 7300000
current number of faces: 7200000
current number of faces: 7100000
current number of faces: 7000000
current number of faces: 6900000
current number of faces: 6800000
current number of faces: 6700000
current number of faces: 6600000
current number of faces: 6500000
current number of faces: 6400000
current number of faces: 6300000
current number of faces: 6200000
current number of faces: 6100000
current number of faces: 6000000
current number of faces: 5900000
current number of faces: 5800000
current number of faces: 5700000
current number of faces: 5600000
current number of faces: 5500000
current number of faces: 5400000
current number of faces: 5300000
current number of faces: 5200000
current number of faces: 5100000
current number of faces: 5000000
current number of faces: 4900000
current number of faces: 5000000
current number of faces: 4900000
current number of faces: 4800000
current number of faces: 4700000
current number of faces: 4600000
current number of faces: 4500000
current number of faces: 4400000
current number of faces: 4300000
current number of faces: 4200000
current number of faces: 4100000
current number of faces: 4000000
current number of faces: 4100000
current number of faces: 4200000
current number of faces: 4300000
current number of faces: 4400000
current number of faces: 4500000
current number of faces: 4600000

Face Quality Faces Percent
< 0.001 668 0.0
< 0.01 1140 0.0
< 0.05 2086 0.0
< 0.1 3310 0.1
< 0.2 7927 0.2
< 0.3 14634 0.3
< 0.4 24830 0.5
< 0.5 47539 1.0
< 0.6 111392 2.4
< 0.7 268694 5.7
< 0.8 855480 18.2
< 0.9 3050971 65.0
< 1.0 4694456 100.0
Worst quality is 0

starting: Improve Quality
current number of faces: 4700000
current number of faces: 4800000
current number of faces: 4900000

Post-processing
found 684 intersections, involving 587 edges, 334 faces, in 39 groups
split 60 edges
moved 98 vertices
now have 681 intersections, involving 618 edges, 347 faces, in 34 groups
removed 3 intersections
collapsed 6 edges
584 faces with quality below 0.05
fixing poor quality and remaining intersections
177 pierced faces remaining
139 pierced faces remaining
137 pierced faces remaining
4 faces with quality below 0.05
Warning: 247 intersecting edges remaining
Warning: 137 intersected faces remaining

Face Quality Faces Percent
< 0.001 1 0.0
< 0.01 1 0.0
< 0.05 4 0.0
< 0.1 174 0.0
< 0.2 1077 0.0
< 0.3 2151 0.0
< 0.4 4466 0.1
< 0.5 6741 0.1
< 0.6 11711 0.2
< 0.7 35947 0.7
< 0.8 311663 6.4
< 0.9 1673011 34.6
< 1.0 4839098 100.0
Worst quality is 0.0001336
final number of faces: 4839098
Aligned mesh created for 312 surfaces out of a total of 9945 surfaces.
2689 thin surfaces fully removed out of 4097 candidate thin surfaces (out of a total of 9945 surfaces).
----------------------------------------
Surface Remesher Completed: CPU Time: 3053.02, Wall Time: 3056.30, Memory: 18957.27 MB
----------------------------------------
Following Parts are Self Intersecting
Surface Wrapper
Command: GenerateVolumeMesh
error: Server Error
Following Parts are Self Intersecting
Surface Wrapper
Command: GenerateVolumeMesh
command: CommandComplete
error: Server Error

Design STAR-CCM+ simulation completed
Server process exited with code : 0

[AndreP]

Started by running the Surface Mesh and having a look at it. I don't know why, but I'm having problem at Contact Patch of the tyres (which I created to avoid problems when CFD!), here are some screen shots! What can/should I do at this area to avoid this distortion of the mesh?

https://imgur.com/uiGJyQW

https://imgur.com/xuRrsyc

https://imgur.com/vBt1eWs

All the rest of the car and mesh, appear to be solid and good quality!

[ping]

this is not the way tires are normally done since they compress on the road so it is best to have flat consuming some of the tire and also maybe a chamfer between the round of the tire and the road
cant see your road either but the surface wrapper surface is certainly not good so you can inspect it in the surface repair tool and work out how to improve the geometry or add some more local refinement or fine tune the wrapper settings

[AndreP]

Hi! Before all, let me thank you for your answer and help!

I did my contact patch based on that! I consumed 2mm of the tyre (Note that the tyres have camber, so thats why the contact patch is not in the centre), after consuming 2mm of the tires, i draw a rectangle around that area and extruded to the tyre to increase the smallest size of the geometry.

THe thing is that when I used Surface Wrapper before, it was ok doing the mesh, so I never really used refinement of Surface Wrapper or any advanced repair tools! Is there any tutorial that can give me around?

On Surface Wrapper I assigned a refinement on that area of contact patch (Target: 1mm, Minimum: 0.5mm), and now I'm trying to run Contact Prevention and Wrapper Defeature between the Tyre itself (not contact patch) and the floor!

Is there other Wrapper settings or tweaks I can use to improve the mesh on this zone?

Thank you

[AndreP]

Also, I'm not using Automatic Surface Repair, do you think this could help solve the problem? I'll try to put another computer to run and use this tool!

[AndreP]

For those who face the same problem. I solved it by using contact prevention and refine a little bit more the area around the contact patch!

Also, on another computer, using the Automatic Surface Repair included in the Automated Mesh seemed to helped and fix the surface at that zone!

[ping]

glad to hear
surface wrapping is a powerful tool with many settings but does take time to both learn to use well and even then you need to sometimes do quite a few wraps to get the detail required or fix problems
read the help as it explains all the options and also has at least two good tutorials in the mesh section that new users should do

[SoAero]

It looks like you wrapped with 29M faces and the used the remember to coarsen it down to 4M faces. The remesh surface is the one with the intersections. The wrapper reports none.

It can be common to use the remesher to coarsen a wrapped surface but this might be extreme.

If you are happy with the wrapped surface: Check the remember settings for the parts which have intersecting faces (find those in manual repair) and use some customs controls to refine those areas.

Maybe, however you don’t need to wrap so finely?

[AndreP]

Originally Posted by SoAero

It looks like you wrapped with 29M faces and the used the remember to coarsen it down to 4M faces. The remesh surface is the one with the intersections. The wrapper reports none.

It can be common to use the remesher to coarsen a wrapped surface but this might be extreme.

If you are happy with the wrapped surface: Check the remember settings for the parts which have intersecting faces (find those in manual repair) and use some customs controls to refine those areas.

Maybe, however you don’t need to wrap so finely?

Now that you say that it's strange, because the cell configurations of both Surface Wrapper and Automatic Mesh (Surface Remesher) were the same! How can they be so different number of face?

[SoAero]

They’re not the same. What is most likely happening is that you’re viewing the root description of the surface wrapper part instead of the remember description.

In the scene displayer property sheet, down at the bottom there is a field for which description to display.