View Issue Details

IDProjectCategoryView StatusLast Update
0002986OpenFOAMBugpublic2018-06-26 21:04
ReporterHTauber Assigned Tohenry  
PrioritynormalSeverityminorReproducibilityalways
Status closedResolutionno change required 
PlatformGNU/LinuxOSUbuntuOS Version16.04
Product Versiondev 
Summary0002986: compressible::turbulentTemperatureRadCoupledMixed runs unstable
DescriptionIn the enclosed sample are two regions (air and solid). The left wall of the region "air) has a temperature of 500 K and radiates heat to the opposite wall "air_to_solid". The mapped wall "air_to_solid" has an additional layer (thickness=0.025, kappa=0.25). The emissivities of the walls are set to 1.0. When you reduce the value of kappa to 0.2 the calculated wall temperature of "air_to_solid" begins to fluctuate. When you still further reduce the value of kappa to 0.1 you get an error. This problem doesn't occur if layers are excluded or radiation is off.
Steps To ReproduceEnclosed you will find an attached case.
TagsNo tags attached.

Activities

HTauber

2018-06-19 09:26

reporter  

case01.tar.gz (6,114 bytes)

henry

2018-06-19 13:50

manager   ~0009797

Have you tried relaxation and increasing the number of PIMPLE iterations?

HTauber

2018-06-20 07:21

reporter   ~0009803

Now I have set kappa to 0.1 and relaxationFactor in fvSolution to 0.3, but the wall temperature of "air_to_solid" doesn't converge. The PIMPLE iterations (do you mean nCorrectors?) has little effect on the calculation. When I make kappa smaller I get an error again.

When I used the boundary condition "externalWallHeatFluxTemperature" I had the same problem, but setting the property "relaxation" to a lower value helped me to come to a convergence.

henry

2018-06-20 08:12

manager   ~0009804

You could try adding the kind of relaxation in the externalWallHeatFluxTemperature BC to the turbulentTemperatureRadCoupledMixed BC.

HTauber

2018-06-20 13:06

reporter   ~0009806

Sorry, but I have not enough experience in programming with C++.

henry

2018-06-20 14:06

manager   ~0009807

This is a good opportunity to gain some experience by studying the existing code and making similar changes elsewhere.

HTauber

2018-06-20 14:22

reporter   ~0009808

I will try, but I need some help. What is the first step?

henry

2018-06-26 21:04

manager   ~0009834

User support or development request, either way requires funding for the OpenFOAM Foundation:

https://openfoam.org/news/funding-2018/
https://openfoam.org/maintenance/

Issue History

Date Modified Username Field Change
2018-06-19 09:26 HTauber New Issue
2018-06-19 09:26 HTauber File Added: case01.tar.gz
2018-06-19 13:50 henry Note Added: 0009797
2018-06-20 07:21 HTauber Note Added: 0009803
2018-06-20 08:12 henry Note Added: 0009804
2018-06-20 13:06 HTauber Note Added: 0009806
2018-06-20 14:06 henry Note Added: 0009807
2018-06-20 14:22 HTauber Note Added: 0009808
2018-06-26 21:04 henry Assigned To => henry
2018-06-26 21:04 henry Status new => closed
2018-06-26 21:04 henry Resolution open => no change required
2018-06-26 21:04 henry Note Added: 0009834