Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 60

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Book Description

Author: B. R. Ramaprian
Publisher:
ISBN:
Category :
Languages : en
Pages : 63

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Book Description
Periodic turbulent boundary layers in zero and adverse time-mean pressure gradient have been studied. The study includes experimental, analytical and numerical investigations. The experiments were conducted in an unsteady-flow water tunnel, in which the freestream velocity varies sinusoidally with time around a mean value. Reduced frequencies up to about 25 and a relative oscillation amplitude of 40 per cent of the mean velocity were studied. Flow reversal occurred over a significant part of the oscillation cycle in the adverse pressure gradient experiments, though no mean-flow separation was observed. Data on turbulent stresses and wall shear stress were obtained using a two-component laser Doppler anemometry and a surface-mounted heat flux gage. A theory and calibration procedure were developed for the use of the latter in unsteady flow. All the experimental data were recorded on magnetic tape. A general asymptotic theory has been developed for unsteady turbulent boundary layers. This theory leads to the development of wall functions for these flows. Such wall functions have been developed and used in a calculation procedure based on the k-epsilon model of turbulence.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

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Book Description

Author: John F. Nash
Publisher:
ISBN:
Category : Navier-Stokes equations
Languages : en
Pages : 116

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Book Description

Author: Lawrence W. Carr
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 62

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Book Description
A comprehensive literature search was conducted and those experiments related to unsteady turbulent boundary-layer behavior were cataloged. In addition, an international survey of industrial, university, and government research laboratories was made, in which new and ongoing experimental programs associated with unsteady turbulent boundary-layer research were identified. Pertinent references were reviewed and classified based on the technical emphasis of the various experiments that include instantaneous or ensemble-averaged profiles of boundary-layer variables are stressed. Detailed reviews that include descriptions of the experimental apparatus, flow conditions, summaries of acquired data, and significant conclusions are made. The measurements made in these experiments that exist in digital form have been stored on magnetic tape, and instructions are presented for accessing these data sets for further analysis. (Author).

Author: Angel Nicolas Menendez
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 226

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Book Description
A turbulent boundary layer, subjected to a free-stream velocity which changes sinusiodally in time under a zero time mean pressure gradient, is studied both experimentally and analytically. Using a two-component Laser Doppler Anemometer and a Heat Flux Gage, detailed and high quality information is obtained on the instantaneous velocity distribution and wall shear stress, respectively, at various stations. An asymptotic theory, for large Reynolds numbers, is developed for the oscillatory motion. It is valid for both boundary layers at arbitrary time-mean pressure gradients and fully developed pipe and channel flow, and is successfully applied to the present and previous available experimental information. The theory identifies two frequency parameters, in terms of which four different frequency regimes are defined. Similarity laws are identified for each one of these frequency regimes. All the experimental data have been archived on magnetic tape. (Author).

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 44

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Book Description
The essential results of a comprehensive review of existing unsteady turbulent boundary-layer experiments are presented. Different types of unsteady flow facilities are described, and the related unsteady turbulent boundary-layer experiments are cataloged and discussed. The measurements that have been obtained in the various experiments are described, and a complete list of experimental results is presented. All the experiments that measured instantaneous values of velocity, turbulence intensity, or turbulent shear stress are identified, and the availability of digital data is indicated. The results of the experiments are analyzed, and several significant trends are identified. An assessment of the available data is presented, delineating gaps in the existing data, and indicating where new or extended information is needed. Guidelines for future experiments are presented. (Author).

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 74

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Book Description

Author: Tuncer Cebeci
Publisher: Elsevier
ISBN: 0323151051
Category : Technology & Engineering
Languages : en
Pages : 423

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Book Description
Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.

Author: Hermann Schlichting (Deceased)
Publisher: Springer
ISBN: 366252919X
Category : Technology & Engineering
Languages : en
Pages : 814

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Book Description
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.