turbulent recirculating flow

Abhijeet Vaidya

hi friends,

You must be aware of ustar & yplus as fluent defines it ! Going by their definitions , I was thinking that they should be exactly same if ystar is > 11.25. But when I solved turbulent flow over an expanding channel (pl note that this is a benchmark problem for laminar flow so the geometry of this channel must be familier to the readers), then yplus goes to zero at the reattachment poing which is obvious but even in the regions where ystar is > 11.25 , there is difference in the value of ystar and yplus which means that even when ystar > 11.25, still u_tau = (cmu^0.25)*(tke^0.5) does not hold ? But theory says otherwise ! Can somebody help ?