Flow separation
Abstract
The calculation is discussed of laminar separation which has always represented one of the most relevant problems of boundary layer theory, even within the classical Prandtl's assumption of vanishing transverse pressure gradients. Recent theories attempting to calculate separation after relaxing Prandtl's assumption are reviewed. Purely numerical results based on the finite difference solution of the complete NavierStokes equations are briefly mentioned. The analytical procedure based on a multiple layer treatment developed independently by Neiland and by Stewartson and Williams is discussed in detail both in the foundations and in the developments. Some as yet unmentioned results are also given. A critical discussion follows, showing the insufficiency of the present asymptotic treatment of the return flow. A third procedure is thought to present a certain interest, that is the generalization of von Karman momentum integral procedure taking into account the existence of transverse pressure gradients. The attempt by Holden and Moselle, containing some arbitrariness, is mentioned. It is shown how the arbitrary elements can be removed and a perfectly coherent set of equations in integral form obtained. The possibility is shown of a fundamental improvement in the calculation of the distributions through the use of a three or fourparameter family of generalized similar solutions taking into account the transverse variability of the pressure.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 February 1976
 Bibcode:
 1976STIN...7623536.
 Keywords:

 Boundary Layer Separation;
 Prandtl Number;
 Separated Flow;
 Fluid Dynamics;
 Laminar Flow;
 Pressure Gradients;
 Turbulent Flow;
 Fluid Mechanics and Heat Transfer