There are two wall functions in OpenFOAM to consider turbulent diffusion near wall.
These two functions are:
I implemented new wall functions based on Ref. 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
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.