On the Equations of a Thick Axisymmetric Turbulent Boundary Layer


Book Description

An examination of the Reynolds equations for axisymmetric turbulent flow where the thickness of the boundary layer is of the same order as the transverse radius of curvature of the surface shows that neither the boundary layer nor the potential flow outside it may be calculated independently of the other, owing to significant interactions between the two flow regimes. Following a discussion of various procedures for extending conventional thin boundary-layer calculation methods to treat thick axisymmetric turbulent boundary-layers, a method is proposed for the simultaneous solution of the boundary layer and the potential flow equations, allowing the two flow regimes to interact. (Author Modified Abstract).







Turbulent Shear Flows I


Book Description

The present book contains papers that have been selected from contributions to the First International Symposium on Turbulent Shear Flows which was held from the 18th to 20th April 1977 at The Pennsylvania State University, University Park, Pennsylvania, USA. Attend ees from close to 20 countries presented over 100 contributions at this meeting in which many aspects of the current activities in turbulence research were covered. Five topics received particular attention at the Symposium: Free Flows Wall Flows Recirculating Flows Developments in Reynolds Stress Closures New Directions in Modeling This is also reflected in the five chapters of this book with contributions from research workers from different countries. Each chapter covers the most valuable contributions of the conference to the particular chapter topic. Of course, there were many additional good con tributions to each subject at the meeting but the limitation imposed on the length of this volume required that a selection be made. The realization of the First International Symposium on Turbulent Shear Flows was p- sible by the general support of: U. S. Army Research Office U. S. Navy Research Office Continuing Education Center of The Pennsylvania State University The conference organization was carried out by the organizing committee consisting of: F. Durst, Universitat Karlsruhe, Karlsruhe, Fed. Rep. of Germany V. W. Goldschmidt, Purdue University, West Lafayette, Ind. , USA B. E. Launder, University of California, Davis, Calif. , USA F. W. Schmidt, Pennsylvania State University, University Park, Penna.




Thick Axisymmetric Turbulent Boundary Layer and Near Wake of a Low-drag Body of Revolution


Book Description

Detailed measurements of pressure distributions, mean velocity profiles and Reynolds stresses were made in the thick, axisymmetric boundary layer and the near wake of a low-drag body of revolution. The data are presented in graphical as well as tabular form for convenience in later analysis. These measurements shed some light on the joint influence of transverse and longitudinal surface curvatures and pressure gradients on the boundary-layer development and on the manner in which an axisymmetric boundary layer becomes a fully-developed wake. Apart from giving a complete set of data on such an important flow configuration, the measurements should provide a fairly rigorous test case for some of the recent turbulence closure models which claim a level of generality not achieved by the older phenomenological models. By inclusion of recently proposed modifications to account for the effects of the extra rates of strain on the turbulence length scale arising from longitudinal and transverse surface curvatures, it is shown that the boundary layer in the tail region of a body of revolution is dominated by the extra strain rates and that more research is needed to account for them properly even in the most recent calculation procedures.







Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.




Advances in Applied Mechanics


Book Description

Advances in Applied Mechanics







Coanda Effect


Book Description

Coanda effect is a complex fluid flow phenomenon enabling the production of vertical take-off/landing aircraft. Other applications range from helicopters to road vehicles, from flow mixing to combustion, from noise reduction to pollution control, from power generation to robot operation, and so forth. Book starts with description of the effect, its history and general formulation of governing equations/simplifications used in different applications. Further, it gives an account of this effect’s lift boosting potential on a wing and in non-flying vehicles including industrial applications. Finally, occurrence of the same in human body and associated adverse medical conditions are explained.