M H Shafiei Mayam - Assistant professor, University of Sistan and Baluchestan

Although the concept of the boundary layer celebrates its 107th birthday in 2011, many fundamental important questions for modeling purposes are still not answered satisfactorily andare still debated. For instance, what is the layer-structure of turbulent boundary layers (TBLs)? What are the pertinent length and velocity scales for each region? What type of overlap layer or layers exists, if any? The lack of satisfactory answers is especially flagrant for the type of turbulentboundary layers most often encountered in applications: non-equilibrium TBLs. The focus of this work is talking and understanding more about different layers in TBLs. In other words, this paper revisits the issue of scaling of TBLs

Scaling, turbulent boundary layer, modeling, equilibrium and non-equilibrium