heat transfer between particle and surface

thanks for your reply, Christoph

it's great.!!
I have got it with your hint.

first import the stl file using 'fix mesh/gran', then bound the simulation using 'fix wall/gran....'.

another question is:

I have not found an import mesh command both calculating the stress and heat transfer.

if I want to calculate both the stress and conductive heat transfer between particle and the triangle surface at the same time when they collide, does any 'fix mesh/gran' command combined both the stress option and the temperature can be used to deal with this problem? (I have dig the description of the command carefully, but caught nothing)

I deal with this problem alternatively.

step 1: import two stl files with same content.(simulation.stl & temperature.stl, temperature.stl is a copy of simulation.stl)

step 2:One command used to specify the stressAnalysis
>>>fix cad1 all mesh/gran/stressanalysis simulation.stl 1 1.0 0. 0. 0. 0. 0. 0. finnie yes

step 3:Another command used to specify the heat transfer:
>>>fix cad2 all mesh/gran simulation.stl 1 1.0 0. 0. 0. 0. 0. 0. temperature 100
>>>fix granwalls all wall/gran/hertz/history 2 cad cad2 temperature 100

step 4:Add the heat transfer parameter for particles
>>>fix ftco all property/global thermalConductivity peratomtype 5.
>>>fix ftca all property/global thermalCapacity peratomtype 10.
>>>fix heattransfer all heat/gran 300.

step 5:Dump stress and wear
>>>dump dumpstress all mesh/gran/VTK 200 post/dump*.vtk stress wear cad

Although it works fine, I am not sure whether a better solution lies somewhere or not...
also another problem focuses on the dump of temperature on the triangular surface, it seems that the dump command is not available.

any suggestion will be highly appreciated.
thx.!
S.L

hello developer,
thanks for the addition of dump mesh temperature in newest version of liggghts.
but some problems confused me:

#1. although temerature can be dumped in the latest version, but things cann't happen as I wish. perhaps something is wrong in my settings.....
several lines in the script are in the following:
>1.set the temperature of mesh.
fix cad all mesh/gran/stressanalysis simple_chute.stl 1 1.0 0. 0. 0. 0. 0. 0. temperature 300 finnie yes
fix tempwalls all wall/gran/hertz/history 1 0 mesh/gran 1 cad temperature 300
>2.set the material property related to heat transfer
#heat transfer
fix ftco all property/global thermalConductivity peratomtype 5.
fix ftca all property/global thermalCapacity peratomtype 10.
fix heattransfer all heat/gran 600.
>3.set the thermo style with f_heattransfer
thermo_style custom step atoms ke c_1 f_heattransfer vol
>4.dump the temperature of mesh
dump dumpstress all mesh/gran/VTK 1000 post/dump*.vtk id stress Temp
but the temperature of the mesh is always 300 even heat is transfered from the particles to surface, perhaps it is hard to calculate the temperature of mesh with the reason that the heatcapacity of the mesh material and the thickness of it are not known. But how can I obtain the conductive heat transfer coefficient or heat flux betwwen the tri-surface and particles. ..

#2.After digged into the source code of dump_mesh.cpp, I am not sure whether it is a trivial error in function DumpMesh::write_item that "SCALARS wear" should be "SCALARS temperature".
if(dump_what & DUMP_TEMP)
{
//write wear data
fprintf(fp,"SCALARS wear float 1\nLOOKUP_TABLE default\n");
for (int i = 0; i < STLList_len; i++) {
for (int j=0;jnTri;j++){
fprintf(fp,"%f\n",STLList[i]->Temp);
//fprintf(fp,"%f\n",(STLList[i]->Area[j]));
}
}
}

#3.I want to obtain the heat transfer coefficient between particles and surface. how can I obtain the heat flux through the surface, is there already an array that records the heat flux value lies in someplace?

#4.as we know, the recent version of liggghts that can dump the mesh temperature is not coupled with openfoam.
so it is possible or not if I change the some codes of the older coupled version.
I have compared the difference between the coupled and the uncoupled version in file dump_mesh.h/cpp, and change the differences. although add a 'double Temp' item in file stl_tri.h.
But the compiled liggghts can't dump this value.

Best regards!
S.L