﻿ Heat transfer between multiple solids and fluids (with radiation) - XSim

# Heat transfer between multiple solids and fluids (with radiation)

OpenFOAM 4.x

## Summary

We consider an analysis domain where the space is divided by a solid domain. Assuming that a heating element is set at the bottom of the solid domain, we calculate the steady state of the entire system. The domain consists of five subdomains as shown below.

Model geometry (region "heater")
Model geometry (region "leftSolid")
Model geometry (region "rightSolid")
Model geometry (region "bottomAir")
Model geometry (region "topAir")

In the region "topAir", the air flows in from the X minimum plane at 0.1 m/s and out from the X maximum plane. The region "bottomAir" is assumed to be filled with air and there is no inflow or outflow of air.

The bottom of the region "heater" is fixed at a temperature of 500 K. The boundary temperature between the heater and the other regions is set to 300 K. Heat conduction conditions are set between each region.

Radiation is taken into account in the analysis. Before starting the solver, we calculate the view factor by using the utilities faceAgglomerate and viewFactorsGen.

After the calculation, the utility "paraFoam" is used to generate .OpenFOAM files for each region. To visualize them, open each .OpenFOAM file from [File]-[Open] in the menu after starting ParaView.

Display all regions

The meshes are as follows, and the number of mesh is 3000.

Meshes (region "heater")
Meshes (region "leftSolid")
Meshes (region "rightSolid")
Meshes (region "bottomAir")
Meshes (region "topAir")

The calculation result is as follows.

Temperature in solid region (T)
Temperature on XY-plane (T)
Flow velocity on XY-plane (U)

## Commands

blockMesh
topoSet
splitMeshRegions -cellZones -overwrite

rm -f 0*/heater/{rho,nut,alphat,epsilon,k,U,p_rgh,Qr,G,IDefault}
rm -f 0*/leftSolid/{rho,nut,alphat,epsilon,k,U,p_rgh,Qr,G,IDefault}
rm -f 0*/rightSolid/{rho,nut,alphat,epsilon,k,U,p_rgh,Qr,G,IDefault}

changeDictionary -region bottomAir
changeDictionary -region topAir
changeDictionary -region heater
changeDictionary -region leftSolid
changeDictionary -region rightSolid

decomposePar -allRegions

mpirun -np 4 faceAgglomerate -region bottomAir -dict constant/viewFactorsDict -parallel
mpirun -np 4 faceAgglomerate -region topAir -dict constant/viewFactorsDict -parallel
mpirun -np 4 viewFactorsGen -region bottomAir -parallel
mpirun -np 4 viewFactorsGen -region topAir -parallel

mpirun -np 4 chtMultiRegionSimpleFoam -parallel

reconstructPar -allRegions

paraFoam -touchAll
paraFoam

We calculate the view factor by using the utilities faceAgglomerate and viewFactorsGen.

After ParaView has been started by the paraFoam command, each .OpenFOAM file must be opened from the menu [File]-[Open].

## Calculation time

24.78 seconds *4 parallel, Inter(R) Core(TM) i7-2600 CPU @ 3.40GHz 3.40GHz