Implement new turbulent diffusion wall function at OpenFOAM

June 3, 2018 Leave a comment Nima Samkhaniani OpenFOAM

There are two wall functions in OpenFOAM to consider turbulent diffusion near wall.
These two functions are:

  • allphatWallFunction
  • alphatJayatillekeWallFunction

I implemented new wall functions based on Ref[1]. These functions are valid for the whole range of yPlus in boundary layer. The new functions are:

  • two layer Han-Reitz function
  • Hybrid Han-Reitz function

Neglecting programming details, following steps are done to implement new wall functions:

  • copy files from alphatWallFunction and rename it to alphatHybridWallFunction
  • add Make folder and it’s content (files and options) to source codes folder
  • implement Tplus and yPlus based on paper
  • calculate alphatEff near wall using following code. alphaEff is sum of molecular and turbulent diffusion.
scalar A = rhow[faceI]*uTau*y[faceI]*Tc[faceI]*log(Tc[faceI]/Tw[faceI])/(Tw[faceI]-Tc[faceI]);
alphaEff =A/Tplus;
  • compile library using wmake libso

Reference:

1. Šarić, S., Basara, B. and Žunič, Z., 2017. Advanced near-wall modeling for engine heat transfer. International Journal of Heat and Fluid Flow, 63, pp.205-211.

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