e.j e Eddy viscosity in the inner and outer regions, respectively, see 

 Equation (2) 



9 Angular coordinate measure in the y-z plane from the z-axis to the 

 line joining the surface offset and elliptic center 



6 Angle between the x and z coordinates 



A* Effective displacement area 



V Kinematic viscosity of the fluid 



p Mass density of the fluid 



T^ Shear stress at the wall 

 tw 



