Turbulent Boundary Layer Equations

• For a two-dimensional flow (w = 0)over a flat plate, the thickness of turbulent boundary layer is assumed to be much smaller than the axial length and the order of magnitude analysis may be applied. As a consequence, the following inferences are drawn:

• The turbulent boundary layer equation together with the equation of continuity becomes

  (33.9)

  
  

  (33.10)

• A comparison of Eq. (33.10) with laminar boundary layer Eq. (23.10) depicts that: u, v and p are replaced by the time average values and ,and laminar viscous force per unit volume is replaced by where is the laminar shear stress and is the turbulent shear stress.