[Malikos]

Hi All,

I try to simulate an axisymmetric hybrid rocket engine in OpenFOAM 3.0.x (git version) with the use of sprayFoam and coneNozzleInjection.

I generated the 2D mesh in Ansys mesher. Then I used fluentMeshToFoam and makeAxialMesh with collapseEdges. I set up a whole case and the simulations starts succesfully and the mesh looks as it is supposed to.

However, after 6e-03 seconds of simulation time the following error appears:
"Hitting a wedge patch should not be possible".
As I understand, the fluid droplet hits the wedge like it would hit the wall, when it should not interact at all.

I encountered many problems during the setting up of this case and I resolved them all, but I have absolutely no idea what to do with this one.

My mesh is in the attachments.

Here is the last iteration:

Courant Number mean: 0.00224303 max: 0.399827
deltaT = 2.05991e-06
Time = 0.001808


Solving 2-D cloud sprayCloud
Cloud: sprayCloud
Current number of parcels = 119
Current mass in system = 2.54503e-08
Linear momentum = (5.37287e-08 2.09017e-08 1.77125e-11)
|Linear momentum| = 5.76511e-08
Linear kinetic energy = 7.04426e-08
model1:
number of parcels added = 119
mass introduced = 2.89028e-08
Parcel fate (number, mass)
- escape = 0, 0
- stick = 0, 0
Temperature min/max = 335.943, 367.479
Mass transfer phase change = 3.4525e-09
D10, D32, Dmax (mu) = 30.8291, 58.3401, 89.1079
Liquid penetration 95% mass (m) = 0.00475127

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
PIMPLE: iteration 1
smoothSolver: Solving for Ux, Initial residual = 0.000568477, Final residual = 6.43949e-08, No Iterations 1
smoothSolver: Solving for Uy, Initial residual = 0.00130768, Final residual = 1.68475e-07, No Iterations 1
smoothSolver: Solving for Uz, Initial residual = 4.90187e-05, Final residual = 2.29524e-09, No Iterations 1


--> FOAM FATAL ERROR:
Hitting a wedge patch should not be possible.

From function void Foam:article::hitWedgePatch(const wedgePolyPatch& wpp, TrackData&)
in file /home/--/OpenFOAM/OpenFOAM-3.0.x/src/lagrangian/basic/lnInclude/particleTemplates.C at line 958.

FOAM aborting

#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::error::abort() at ??:?
#2 void Foam:article::hitWedgePatch<Foam:article::Trac kingData<Foam::KinematicCloud<Foam::Cloud<Foam::Sp rayParcel<Foam::ReactingParcel<Foam::ThermoParcel< Foam::KinematicParcel<Foam:article> > > > > > > >(Foam::wedgePolyPatch const&, Foam:article::TrackingData<Foam::KinematicCloud< Foam::Cloud<Foam::SprayParcel<Foam::ReactingParcel <Foam::ThermoParcel<Foam::KinematicParcel<Foam:a rticle> > > > > > >&) at ??:?
#3 ? at ??:?
#4 ? at ??:?
#5 ? at ??:?
#6 ? at ??:?
#7 ? at ??:?
#8 ? at ??:?
#9 __libc_start_main in "/usr/lib/libc.so.6"
#10 ? at ??:?
Aborted (core dumped)

Here is the checkMesh log:

Time = 0

Mesh stats
points: 2333
internal points: 0
faces: 4394
internal faces: 2047
cells: 1096
faces per cell: 5.87682
boundary patches: 8
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 961
prisms: 135
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 0

Checking topology...
Boundary definition OK.
Cell to face addressing 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
walls 92 188 ok (non-closed singly connected)
oxygen_injector 1 4 ok (non-closed singly connected)
fuel_injector 1 3 ok (non-closed singly connected)
center 0 0 ok (empty)
otoczenie 61 123 ok (non-closed singly connected)
frontAndBackPlanes 0 0 ok (empty)
frontAndBackPlanes_pos1096 1227 ok (non-closed singly connected)
frontAndBackPlanes_neg1096 1227 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (0 0 -0.00287888) (0.46 0.066 0.00287888)
Mesh has 2 geometric (non-empty/wedge) directions (1 1 0)
Mesh has 3 solution (non-empty) directions (1 1 1)
Wedge frontAndBackPlanes_pos with angle 2.49762 degrees
Wedge frontAndBackPlanes_neg with angle 2.49762 degrees
All edges aligned with or perpendicular to non-empty directions.
Boundary openness (-6.19848e-19 4.16499e-17 -3.82515e-16) OK.
Max cell openness = 2.39508e-16 OK.
Max aspect ratio = 3.22353 OK.
Minimum face area = 1.09048e-08. Maximum face area = 0.000100913. Face area magnitudes OK.
Min volume = 8.47208e-11. Max volume = 4.61536e-07. Total volume = 5.94948e-05. Cell volumes OK.
Mesh non-orthogonality Max: 32.5706 average: 9.6653
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 0.718396 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

However it is preceded by more than 10 000 lines of warning, all the type of:

--> FOAM Warning :
From function wedgePolyPatch::calcGeometry(PstreamBuffers&)
in file meshes/polyMesh/polyPatches/constraint/wedge/wedgePolyPatch.C at line 72
Wedge patch 'frontAndBackPlanes_neg' is not planar.
At local face at (0.228374 0.0315312 -0.00137537) the normal (1.39832e-07 -0.0435775 -0.99905) differs from the average normal (-3.40834e-09 -0.043578 -0.99905) by 2.09134e-13
Either correct the patch or split it into planar parts

I think that the above is the cause of the problem. Can someone help me repair this mesh? In the meantime I will make it directly in blockMesh and post here if it helped.

Can anybody please give me any advice?

EDIT:
All of the warnings dissapered after I changed writeFormat to binary in controlDict and generated the mesh once again.
Unfortunately, the "hitting the wedge" error still occurs, so it was not caused by the mesh errors.

The main problem is still not solved.

[Malikos]

Well, in this thread:
http://www.cfd-online.com/Forums/ope...ieselfoam.html
user "kmpang" posted the solution to my problem.

According to that user and the paper that he quoted: http://www.dhcae-tools.com/images/dh...rcelSolver.pdf
I should just comment the code about this error in the particleTemplates file and it will be okay.

It can cause some errors in the results according to:
http://www.cfd-online.com/Forums/ope...teraction.html,
but, as the authors said, the results they obtained were satisfying for them.

So, maybe it is a bit of cheating, but it is worth a try if simulating a whole 3D case is too expensive.