Interacting Supersonic Turbulent Boundary Layers Over a Two-dimensional Protuberance
Interacting Supersonic Turbulent Boundary Layers Over a Two-dimensional Protuberance

Author: Arnold Polak

Publisher:

Published: 1974

Total Pages: 38

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The report presents a numerical study of attached interacting supersonic turbulent boundary layers over a two-dimensional protuberance. Results are presented in terms of surface pressure, heat transfer and skin-friction distributions. These results indicate a strong effect of the size of the protuberance, Mach number, but a weak effect of Reynolds number and the ratio of wall-to-recovery temperature. The peak heating rates from a set of test cases compare well to a semi-empirical prediction method. In contradistinction to the laminar case, the turbulent recovery zone downstream of the protuberance is very short. (Author).

Research on Supersonic Turbulent Separated and Reattached Flows
Research on Supersonic Turbulent Separated and Reattached Flows

Author: Seymour M. Bogdonoff

Publisher:

Published: 1975

Total Pages: 94

ISBN-13:

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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.

Separation Ahead of Protuberances in Supersonic Turbulent Boundary Layers
Separation Ahead of Protuberances in Supersonic Turbulent Boundary Layers

Author: Raymond Sedney

Publisher:

Published: 1977

Total Pages: 31

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The data were obtained using the optical-surface indicator technique of visualizing the flow; its accuracy and reproducibility are discussed. The protuberances are immersed in the boundary layer on the wall of a supersonic wind tunnel. The relative importance of various non-dimensional groups is evaluated. The variation of primary separation distance is presented as a function of obstacle dimensions, Mach number, and Reynolds number, the last being the least significant. These results do not support some scaling laws found in the literature. An alternative correlation is proposed which applies to both small and large cylindrical protuberances. (Author).

Boundary Layer Transition at Supersonic Speeds
Boundary Layer Transition at Supersonic Speeds

Author: E. R. Van Driest

Publisher:

Published: 1961

Total Pages: 108

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Experiments carried out in the 12-inch supersonic wind tunnel to investigate the effect of three dimensional roughness elements (spheres) on boundary-layer transition on a 10-degree (apex angle) cone without heat transfer are described. The local Mach number for these tests was 2.71. The data show clearly that the minimum (effective) size of trip required to bring transition to its lowest Reynolds number varies power of the distance from the apex of the cone to the trip. Use of available data at other Mach numbers indicates that the Mach number influence for effective tripping is taken into account by a simple expression. Some remarks concerning the roughness variation for transition on a blunt body are made. Finally, a general criterion is introduced which gives insight to the transition phenomenon and anticipates effects of external and internal disturbances, Mach number transfer.