Heat Transfer In Subsonic Separated Flows

This book presents the results of scientific research performed over the past two decades by the authors. The book discusses some issues of separated laminar flows that are of great practical interest for the development of new technologies using microchannel flows, where separation zones can form. Of particular interest is the complex mechanism of flow separation with superimposed high external turbulence. The challenges of finding the optimal location for the cavities and fins on heat exchange surfaces are also considered. This is an important fundamental and practical problem when creating new schemes of efficient heat exchangers in various power plants. A wide class of problems of turbulent flow in tubes with flow separation is considered. These data will be useful in engineering estimates of the thermal–hydraulic efficiency of various heat transfer intensifiers. This book focuses on the analysis of thermal characteristics of separated flows, as well as the possibility of controlling the intensity of heat exchange processes, from the point of view of both their intensification and their suppression.

Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation. Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapters consider the study of flow separation on the two-dimensional body, flow separation on three-dimensional body shape and particularly on bodies of revolution. This book discusses as well the analytical solutions of the unsteady flow separation. The final chapter deals with the purpose of separation flow control to raise efficiency or to enhance the performance of vehicles and fluid machineries involving various engineering applications. This book is a valuable resource for engineers.

A brief review of the Project THEMIS research program in 'separated flows' is presented. The review covers (1) Smooth wall separation in oscillating flow, (2) Turbulent subsonic axisymmetric near-wake, (3) Convective heat transfer in separated flow, (4) Supersonic axisymmetric near-wake, (5) Nonequilibrium processes in separated flow, (6) Numerical methods for free shear layer problems, and (7) Flow reattachment. (Author).

Separated flows and jets are closely linked in a variety of applications. They are of great importance in various fields of fluid mechanics including vehicle efficiency, technical branches concerned with gas/liquid flows, atmospheric effects on various constructions, etc. Knowledge of the physics of separated flows and jets and the development of reliable control techniques are prerequisite for future progress in the field. These aspects were in focus during the IUTAM-Symposium which was held in Novosibirsk, 9-13 July, 1990. This volume contains a selection of papers presenting recent results of theoretical and numerical studies as well as experimental work on separated flows and jets. The topics include sub- and supersonic, laminar and turbulent separation as well as organized structures in separated flows and jets. The reader will find here the state of the art and major trends for research in this field of aero-hydrodynamics.

Some results are described of fundamental research conducted on various flow separation phenomena in two-dimensional streams. Experimental and theoretical results are described for the pressure rise across a reattachment region, and for the Reynolds number dependence of the pressure rise to a separation point. Observations are made throughout of the location of transition relative to reattachment and to separation, since this relative location turned out to be the dominant variable investigated.

Heat transfer rates are measured in the separated flow region behind the two-dimensional sharp protruding leading edge step model (boundary layer thickness is zero at the separation point) in the high enthalpy laminar near subsonic and supersonic flow in the shock tube. The measurements are carried out in a shock Mach number range from 2.3 to 10, and a corresponding flow Mach number range from 0.5 to 2.62. The Reynolds number, which is based on the height of the leading edge above the flat plate where the heat transfer rates are measured, varies from 300 to 17,000, and the local Reynolds number on the plate varies from 700 to 290,000. The results are correlated in terms of the non dimensional parameters of Nusselt number as a function of the Mach and Reynolds numbers and stagnation to wall enthalpy ratio. The variations of local, average and maximum heat transfer rates are presented. (Author).