Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 66

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Book Description

Author: Walter Bruce Gillette
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 111

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Book Description
To the designer of modern high-speed aerospace vehicles, separation of the boundary layer before macroscopic surface features is an important problem. A typical feature of interest is a compression corner, or ramp. To aid in the development of comprehensive theories concerning boundary layer separation before a compression corner, a series of experimental investigations were conducted for the adiabatic flow of a supersonic compressible gas over a compression corner. Tests were conducted at free-stream Mach Numbers of 2.00 to 4.00 in increments of 0.50, at flat plate Reynolds Numbers of 0.75 x 10 to the 7th and 1.5 x 10 to the 7th, and for compression angles of 10.3 deg, 20.1 deg, 30.5 deg, and 39.9 deg. Static pressure surveys of the flow ahead of and over the compression corner were made. These measurements were supplemented by high-speed schlieren photographs and shadowgraphs. The separation of the turbulent compressible boundary layer was found to have strong dependence on both the Mach Number and the Reynolds Number. For Mach Numbers less than 3.00, the separation distance ahead of the compression corner decreased with increasing Mach Number. For Mach Numbers of 3.50 and 4.00, the separation distance increased with Mach Number. At all Mach Numbers, an increase in Reynolds Number increased the separation distance. The Reynolds Number influence was greater at the higher Reynolds Numbers. Unsteadiness in the separation geometry occurred for separation distances greater than six or eight boundary layer thicknesses. The separation was found to result from a free interaction of the flow phenomena involved. (Author).

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702

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Author: Seymour M. Bogdonoff
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 94

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Book Description
Basic research programs are reported with fundamental applications to supersonic flight. The experimental studies made use of the unique capabilities of the high Reynolds number Mach 3 facility. The experimental programs concentrated on phenomena associated with incipient separation and separation of turbulent boundary layers over a large Reynolds number range. The reattachment phenomena of a shear layer was also studied in great depth.

Author: W. B. Sturek
Publisher:
ISBN:
Category :
Languages : en
Pages : 58

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Book Description
The experimental data reported in Part 1 are analyzed. Turbulent boundary layer equations applicable to compressible flow over a surface with longitudinal curvature are evaluated by numerical integration using the tabulated profile data. Curvature corrections to the equation for conservation of streamwise momentum are shown to be small but of the same order of magnitude as the wall shear stress. The data are shown to correlate in law of the wall and velocity defect dimensionless coordinates using an integral compressibility transformation. Values of skin friction coefficient calculated using the experimental data are compared to other experimental data and to values predicted using the Spalding-Chi method. (Author).

Author: Muhammad Farrukh Shahab
Publisher: LAP Lambert Academic Publishing
ISBN: 9783848415151
Category :
Languages : en
Pages : 228

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Book Description
As a prerequisite for relevant model development and improvement of design methodologies for supersonic vehicles, this study aims at investigating the influence of wall heat-transfer and shock interaction on the turbulence structure of supersonic boundary layers. Incipient separation conditions and two different wall thermal boundary conditions (adiabatic and cold) are considered. The analysis focuses on the evolution of mean and turbulent flow properties along the interaction region and in the relaxation region downstream of the shock-system. The strong influence of the mean pressure gradient is quantified through the analysis of mean flow profiles and boundary layer integral parameters. The anisotropic amplification of turbulent quantities through the interaction region is characterized and the turbulent events associated with the modification of the turbulence structure of the perturbed boundary layer are identified. The mean and turbulent thermal fields are shown to be strongly modified by the wall cooling which significantly dampens more particularly the turbulent thermal quantities levels across the boundary layer.

Author: Alexander J. Smits
Publisher:
ISBN:
Category : Rayleigh scattering
Languages : en
Pages : 40

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Author: William A. Cassels
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 76

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Book Description
Boundary-layer transition by the sublimation and impact-pressure techniques and force tests have been performed on three Haack-Adams bodies of revolution of fineness ratios 7, 10, and 13 at zero angle of attack for free-stream Mach numbers of 2.00, 2.75, and 4.63 and a range of Reynolds numbers based on model length of 6 to 15 X 10(to the 6 power) with and without a roughness strip. The grit method of inducing turbulence was found to provide for a nearly complete turbulent flow over the models at the lower Mach numbers and higher Reynolds numbers considered in this study while the amount of trip drag was less than 8 percent of the model drag with transition fixed. A method of interpreting sublimation data was discussed and used and the results compared well with the impact-pressure results.

Author: John Eldon Lewis
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 256

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Book Description

Author: Holger Babinsky
Publisher: Cambridge University Press
ISBN: 1139498649
Category : Technology & Engineering
Languages : en
Pages : 481

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Book Description
Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.