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Turbulent wall fire case with Ahmed and faith 1978 by custmised solver of fire

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Old   September 27, 2017, 21:10
Default Turbulent wall fire case with Ahmed and faith 1978 by custmised solver of fire
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Zhiheng Wang
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Hi Fomers,
The thread includes result validation for HeatFluxParameters for Ahmed and faith 1978 paper with RANS simulation under natural convective medium. The problem arises to calculate wall normal distance Yplus calulation and validation with boundary condition and profile capture.
Solver is modified reactingParcelFilmFoam.

I am doubt about approaches and boundary condition at wall to get right Yplus and Viscous sublayer which approach is better ??

1. first appoach i learnt is to Refine the grid finner so viscous sublayer falls out 1st cell cell center of boundary , with nut , alphat epsilon at wall zero gradient condition so extrapolation will be laminar only with k =0 as fixed value at wall.

2. Second approach is about wall function , but which wall fuction to be use for this case as natural convection is Grashoff and rayLeigh number dependent.

Please find the attachments.
Journal and experimental results refered from
TURBULENT WALL FIRES
T. AHMAD AND G. M. FAETH
Mechanical Engineering Department, The Pennsylvania State University, University Park, PA
Attached Images
File Type: jpg GrPr.jpg (26.6 KB, 20 views)
File Type: jpg HFPALL.jpg (34.9 KB, 20 views)
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Old   October 27, 2017, 12:42
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Zhiheng Wang
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Either Combustion in OPENFOAM is hopeless or people are reluctant to answer on forums, pity really
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