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IDProjectCategoryView StatusLast Update
0000066OpenFOAMBugpublic2021-07-13 15:22
Reporteruser25Assigned Touser2 
Status resolvedResolutionfixed 
PlatformLinuxOSFedoraOS Version12
Summary0000066: Temperature increases beyond inlet temperatures with reactions off
DescriptionSolved for only species transport, the CounterflowFlame2D tutorial file (in version 1.7.1) using reactingFoam.
Specified reactions off and turbulent reactions off in constant/chemistryProperties.
Temperatures at both inlets are 800K (as was given in the tutorial file). No other modificattion in the files.
As no reactions, one would expect temperatures to be below 800K as only species transport.
However, the temperature increased beyond 800 K (it went close to 840 K - log file is attached).
Why temperatures should increase if there is no heat generation due to reaction?
TagsNo tags attached.



2010-10-26 08:16


log.rar (315,096 bytes)


2010-10-26 17:08


Our reactingFoam algorithm is an efficient, approximate method for turbulent reacting flow. However, in the laminar limit the approximation breaks down, leading to temperature inconsistencies.

In the laminar case, if you have a composition gradient, the only way to ensure that the diffusion does not give rise to temperature errors is by enforcing a Lewis no = 1 constraint, e.g. update the sensible enthalpy eqn to:

    fvScalarMatrix hsEqn
        fvm::ddt(rho, hs)
      + mvConvection->fvmDiv(phi, hs)
// - fvm::laplacian(turbulence->alphaEff(), hs)
      - fvm::laplacian(turbulence->muEff(), hs) // unit lewis no.
      + chemistrySh

This is an area that we would like to research and update in the future if we gain sponsorship to do so.

Issue History

Date Modified Username Field Change
2010-10-26 08:16 user25 New Issue
2010-10-26 08:16 user25 File Added: log.rar
2010-10-26 09:15 user2 Priority urgent => normal
2010-10-26 09:16 user2 Assigned To => user2
2010-10-26 09:16 user2 Status new => assigned
2010-10-26 17:08 user2 Note Added: 0000094
2010-10-26 17:08 user2 Status assigned => resolved
2010-10-26 17:08 user2 Resolution open => suspended
2021-07-13 15:22 henry Resolution suspended => fixed