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IDProjectCategoryView StatusLast Update
0003368OpenFOAMContributionpublic2019-10-23 14:28
ReportervijayAssigned Towill 
PrioritynormalSeverityminorReproducibilityalways
Status closedResolutionno change required 
PlatformGNU/LinuxOSUbuntuOS Version15.04
Product Version6 
Fixed in Version 
Summary0003368: Correct enthalpy transport even when specie specific heats are a function of temperature
DescriptionThis is a continuation of bug report "0003363: Solved unphysical temperature fields in multi-species gas tranport solver". Through the commit 54f379f668485bd2af0d05518c6a9eb5e20ca5a9, the unphysical temperature fields issue in reactingFoam solver was overcome. This is Lewis Number = 1 formulation. In the bug report mentioned above, I had said that this rectification will work only as long as specie specific heats are not a function of temperature. "Will" didn't agree with my argument and had asked for a case to justify my argument. I was not able to come up with a OpenFOAM case, but here I have attached the necessary files to test the effect mathematically.

In conclusion, I was wrong and Will was right. The current implementation in reactingFoam solver gives correct enthalpy transport even when specie specific heats are a function of temperature.

Math Expressions.pdf
- Discusses the expressions in Exact form and the form implemented in OpenFOAM

Excercise:
- A one dimensional domain of length = 1 m. Two gases Hydrogen and Air. The mass fraction of Hydrogen varies linearly from 0 at x=0 to 1 at x=1. For Air it varies from 1 at x=0 to 0 at x=1.
- Temperature varies linearly from 275 K at x=0 to 2000K at x=1.

Case1:
- Cp_Hydrogen and Cp_Air constant with temperature
- Result: CpiConstWithTemperature.png
Case2:
- Cp_Hydrogen and Cp_Air varies with temperature (polynomial function).
- Result: CpiVaryWithTemperature.png
Steps To ReproduceNone
Additional InformationNone
TagsNo tags attached.

Activities

vijay

2019-10-11 14:18

reporter  

Math Expressions.pdf (518,029 bytes)
CpiConstWithTemp.py (1,454 bytes)
CpiVarWithTemp.py (2,733 bytes)

will

2019-10-23 14:28

manager   ~0010847

Great. Thanks for confirming that it works with variable specific heats.

Issue History

Date Modified Username Field Change
2019-10-11 14:18 vijay New Issue
2019-10-11 14:18 vijay File Added: Math Expressions.pdf
2019-10-11 14:18 vijay File Added: CpiConstWithTemp.py
2019-10-11 14:18 vijay File Added: CpiVarWithTemp.py
2019-10-11 14:18 vijay File Added: CpiConstWithTemperature.png
2019-10-11 14:18 vijay File Added: CpiVaryWithTemperature.png
2019-10-23 14:28 will Assigned To => will
2019-10-23 14:28 will Status new => closed
2019-10-23 14:28 will Resolution open => no change required
2019-10-23 14:28 will Note Added: 0010847