The application of the well-known basic principle of mechanics, the principle of Jourdain, to problems of the theory of the boundary layer leads to an equation from which the equations of Von Karman, Leibenson, and Golubev are derived as special cases. The given equation may be employed in other integral methods. The present paper deals with the method of the variation of the thickness of the boundary layer. A number of new approximate formulas valuable in aerodynamic calculations for the fristion distribution are derived from this procedure. The method has been applied only to laminar boundary layers, but it seems probable that it may be generalized to include turbulent layers as well.

This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.

A number of the most promising integral methods for soliving approximately the compressible-laminar-boundary-layer equations are investigated in order to determine a convenient and accurate method of calculating boundary-layer characteristics. The chief methods considered are the one-parameter Karman-Pohlhausen method with three different assumptions for the velocity profiles and the two-parameter method with two different assumptions for the velocity profiles. Comparison of the results is made with those of known exact solutions for skin-friction and heat-transfer coefficients, velocity profiles, velocity derivatives, and especially laminar-boundary-layer stability. From this comparison, it is found that Karman-Pohlhausen method with the sixth-degree polynomial as the velocity is the most suitable for many practical purposes.

A new edition of the almost legendary textbook by Schlichting completely revised by Klaus Gersten is now available. This book presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with emphasis on the flow past bodies (e.g. aircraft aerodynamics). It contains the latest knowledge of the subject based on a thorough review of the literature over the past 15 years. Yet again, it will be an indispensable source of inexhaustible information for students of fluid mechanics and engineers alike.

The two-parameter momentum-integral method of M.R. Head for the calculation of two-dimensional or axisymmetric, incompressible, laminar boundary layers is reworked into an analytical form, thereby eliminating the graphical data of Head's original method. The revised method is coded for digital computer solution and a number of test cases are computed. The numerical results for these test cases are compared with very accurate boundary layer solutions obtained by a finite-difference method and also results obtained using the Pohlhausen momentum-integral method. It was found that the Head method is vastly superior to the Pohlhausen method yet requires only about the same computational expense. Head's method yields very accurate results even for highly nonsimilar boundary layers. (Author).