  The Prandtl Plus scaling parameters are reexamined theoretically. The flow
governing equations approach is used to examine similarity issues of the inner
region of wall-bounded turbulent flows as well as laminar flow cases. It is
found that the Prandtl Plus parameters are in fact similarity scaling
parameters for laminar sink flow but NOT the more general laminar Falkner-Skan
boundary layer flows. For turbulent boundary layer flows along a wall, it is
found that only turbulent sink flows show similarity with the Prandtl Plus
scaling parameters. This is diametrically opposed to the accepted notion that
the Prandtl Plus parameters work for every wall-bounded turbulent flow. To
correct the problem with the Prandtl Plus parameters, we introduce a new set of
scaling parameters that work for the Falkner-Skan boundary layer flows and
satisfy the relevant part of the flow governing equations approach to
similarity.

Fluid Dynamics