On the Structure of Three-Dimensional Shock-Induced Separated Flow Regions PDF Download

Author: R. H. Korkegi
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
A study is made of existing experimental data on three-dimensional skewed shock-wave interactions with both laminar and turbulent boundary layers and recent results in which extensive regions of turbulent separation were obtained. Comparisons show that the structure of three-dimensional shock-wave/boundary-layer interactions is not fundamentally different for laminar or turbulent flow; it is primarily dependent on the extent of separation. A qualitative description is given for the flow structure from incipient to large extents of separation. For the latter, a secondary incipient condition arises within the primary separation vortex. For still larger extents of separation it is deduced that a secondary vortex arises adjacent to the surface and totally embedded in the primary separation vortex. (Author).

Author: Yu A. Panov
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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The results of an experimental investigation of the structure of a separated flow on a flat plate in the region of a three-dimensional shock wave - turbulent boundary layer interaction are presented for free-stream Mach number equal to 3 and Reynolds number Re equals 1.8 x 10(superscript 7). The aim of the investigation is to clarify the general principles governing three-dimensional separated flows induced by the intersection of shock waves formed by obstacles on the body surface with the boundary layer, and to supplement the scarce data available up to now. A schematic presentation of the flow pattern is given. The relationship between the characteristic geometric dimensions of the separation zone and the intensity of the incident shock wave is studied. A comparison is made between two- and three-dimensional cases. (Author).

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.

Author: D. D'Ambrosio
Publisher:
ISBN:
Category :
Languages : en
Pages : 38

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 22

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Author: Jean Délery
Publisher: John Wiley & Sons
ISBN: 1118579887
Category : Science
Languages : en
Pages : 181

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Book Description
This book develops concepts and a methodology for a rational description of the organization of three-dimensional flows considering, in particular, the case where the flow is the place of separations. The descriptive analysis based on the critical point theory of Poincaré develops conventional but rather unfamiliar considerations from aerodynamicists, who face the understanding of complex flows including multiple separation lines and vortices. These problems concern industrial sectors where aerodynamics plays a key role, such as aerospace, ground vehicles, buildings, etc. Contents 1. Skin Friction Lines Pattern and Critical Points. 2. Separation Streamsurfaces and Vortex Structures. 3. Separated Flow on a Body. 4. Vortex Wake of Wings and Slender Bodies. 5. Separation Induced by an Obstacle or a Blunt Body. 6. Reconsideration of the Two-Dimensional Separation. 7. Concluding Remarks. About the Authors Jean Délery is a Supaero (French National Higher School of Aeronautics and Space) engineer who has worked at Onera (French national aerospace research center) since 1964. He has participated in several major French and European aerospace programs, is the author of many scientific publications, and has occupied various teaching positions particularly at Supaero, the University of Versailles-Saint-Quentin, Ecole polytechnique in France and “La Sapienza” University in Rome, Italy. He is currently emeritus adviser at Onera.

Author: Seymour M. Bogdonoff
Publisher:
ISBN:
Category :
Languages : en
Pages : 75

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An extensive experimental study of three-dimensional shock wave turbulent boundary layer interactions caused by shock generators defined solely by angles has been carried out at Mach 3. Sharp fins, sharp swept fins, swept wedges, and semi-cones have been used to generate a wide range of shock waves. The interaction of these waves with turbulent boundary layers has been investigated by surface flow visualization, mean surface static pressure distributions, flowfield surveys of total pressure and yaw, and several flowfield visualization techniques. Some exploratory high frequency surface pressure measurements have been carried out to evaluate the steadiness of these interactions. Scaling laws for both surface and flowfield features have been derived. Some limited studies were carried out at a Mach number of 2. A flowfield study has shown that the initial part of interactions caused by the same strength and geometrical shock wave generated by different shock generators are all similar. The 'footprints' of the interactions, as shown by surface flow visualization, can be categorized as approximately conical or cylindrical, and the boundaries between these two regions have been defined for both Mach 3 and Mach 2. There are still questions with regards to the detailed flowfield structures and physical mechanisms, but the three-dimensional interactions appeared to be less unsteady than that of two-dimensional separated flows.

Author: Piotr Doerffer
Publisher: Springer Science & Business Media
ISBN: 3642030041
Category : Technology & Engineering
Languages : en
Pages : 350

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Book Description
This volume contains description of experimental and numerical results obtained in the UFAST project. The goal of the project was to generate experiment data bank providing unsteady characteristics of the shock boundary layer interaction. The experiments concerned basic-reference cases and the cases with application of flow control devices. Obtained new data bank have been used for the comparison with available simulation techniques, starting from RANS, through URANS, LES and hybrid RANS-LES methods. New understanding of flow physics as well as ability of different numerical methods in the prediction of such unsteady flow phenomena will be discussed.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26

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Author: B. Oskam
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Book Description
An exploratory experimental investigation has been carried out on the three dimensional flow fields caused by the interaction of oblique shock waves and a planar turbulent boundary layer. The study was performed at a free stream Mach number of 2.95, a Reynolds number per inch of 1.6 million and near adiabatic wall conditions. The interaction was studied on two experimental configurations having different initial boundary layer thicknesses (delta = approx. 0.13 and 0.55 inches). Both surface measurements as well as complete flow field surveys were performed. The main contributions of the present investigation are two experimentally derived flow field models for shock generator angles of 4 deg and 10 deg. Based upon both static pressure and surface flow patterns, as well as heat transfer data, the interaction region can be characterized as quasi-two-dimensional along the shock direction in the region studied. A critical examination of the occurrence of 'ordinary' flow separation and its character, as applied to the present problem, was carried out. It was concluded that McCabe's criterion, as used by the previous investigators, is not a sufficient condition to determine the onset of flow separation.