Investigation of Turbulent Separated Flows in the Vicinity of Fin-type Protuberances at Supersonic Mach Numbers

Investigation of Turbulent Separated Flows in the Vicinity of Fin-type Protuberances at Supersonic Mach Numbers PDF Author: Earl A. Price (Jr.)
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 82

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Flow Visualization Studies of a Fin Protuberance Partially Immersed in a Turbulent Boundary Layer at Mach 5

Flow Visualization Studies of a Fin Protuberance Partially Immersed in a Turbulent Boundary Layer at Mach 5 PDF Author: Allen Edward Winkelmann
Publisher:
ISBN:
Category : Flow visualization
Languages : en
Pages : 84

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Various flow-visualization results are presented for a cylindrically blunted, unswept fin (yawed and unyawed) partially immersed in a turbulent boundary layer (delta approx. = 2.6 inches). The model, consisting of a fin-flat plate combination, was tested at a nominal Mach number of 5 and nominal free-stream Reynolds numbers per foot of 2800 000 and 7400 000. Azobenzene tests show regions of high heat transfer on the flat plate immediately upstream and downstream of the fin. Oil smear tests show in detail the surface shear directions and locations of separated flow which occur on the model. Schlieren and shadowgraph photographs indicate the complex shock wave structure which exists in front of the fin. A possible flow-field model is suggested to account for the observed flow patterns. (Author).

NASA Technical Note

NASA Technical Note PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 856

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Flow-field Measurements Downstream of Two Protuberances on a Flat Plate Submerged in a Turbulent Boundary Layer at Mach 2.49 and 4.44

Flow-field Measurements Downstream of Two Protuberances on a Flat Plate Submerged in a Turbulent Boundary Layer at Mach 2.49 and 4.44 PDF Author: Lana M. Couch
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 146

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Characterization of the Flowfield Near a Wrap-Around Fin at Supersonic Speeds

Characterization of the Flowfield Near a Wrap-Around Fin at Supersonic Speeds PDF Author: Carl P. Tilmann
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 166

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Book Description
A wall-mounted semi-cylindrical model fitted with a single wrap- around in (WAF) has been investigated numerically and experimentally, with the objective of characterizing the mean and turbulent flowfield near a WAF in a supersonic flowfield. Numerical and experimental results are used to determine the nature of the flowfield and quantify the effects of fin curvature on the character of the flow near WAFs. This research has been motivated by the need to identify possible sources of a high-speed rolling moment reversal observed in sub-scale flight tests. Detailed mean flow and turbulence measurements were obtained in the AFIT Mach 3 wind tunnel using conventional probes and cross-wire hot-film anemometry at a series of stations upstream of and aft of the fin shock/boundary layer interaction. Hot-film anemometry results showed the turbulence intensity and Reynolds shear stress in the fuselage boundary layer to be far greater on the concave side of the fin than on the convex side. Mean flow was also obtained in the AFIT Mach 5 wind tunnel using conventional pressure probes. Numerical results were also obtained at the test conditions employing the algebraic eddy viscosity model of Baldwin and Lomax. Correlation with experimental data suggests that the calculations have captured the flow physics involved in this complicated flowfield. The calculations, corroborated by experimental results, indicate that a vortex exists in the fin/body juncture region on the convex side of the fin. This feature is not captured by the oft- used inviscid methods, and can greatly influence the pressure loading on the fin near the root.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1370

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

NASA Technical Paper

NASA Technical Paper PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 120

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Boundary Layer Effects

Boundary Layer Effects PDF Author: Anthony W. Fiore
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 962

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Book Description
In 1975 the U.S. Air Force and the Federal Republic of Germany signed a Data Exchange Agreement numbered AF-75-G-7440 entitled 'Viscous and Interacting Flow Fields.' The purpose was to exchange data in the area of boundary layer research. It includes both experimental and theoretical boundary layer research at speeds from subsonic to hypersonic Mach numbers in the presence of laminar, transitional, and turbulent boundary layers. The main effort in recent years has been on turbulent boundary layers, both attached and separated in the presence of such parameters as pressure gradients, wall temperature, surface roughness, etc. In the United States the research was conducted in various Department of Defense, NASA, aircraft corporations, and various university laboratories. In the Federal Republic of Germany it was carried out within the various DFVLR, industrial, and university research centers.

NASA Scientific and Technical Reports

NASA Scientific and Technical Reports PDF Author: United States. National Aeronautics and Space Administration Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 428

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Turbulent Shear-Layer/Shock-Wave Interactions

Turbulent Shear-Layer/Shock-Wave Interactions PDF Author: J. Delery
Publisher: Springer Science & Business Media
ISBN: 3642827705
Category : Science
Languages : en
Pages : 434

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Book Description
It was on a proposal of the late Professor Maurice Roy, member of the French Academy of Sciences, that in 1982, the General Assembly of the International Union of Theoretical and Applied Mechanics decided to sponsor a symposium on Turbulent Shear-Layer/Shock-Wave Interactions. This sympo sium might be arranged in Paris -or in its immediate vicinity-during the year 1985. Upon request of Professor Robert Legendre, member of the French Academy of Sciences, the organization of the symposium might be provided by the Office National d'Etudes et de Recherches Aerospatiales (ONERA). The request was very favorably received by Monsieur l'Ingenieur General Andre Auriol, then General Director of ONERA. The subject of interactions between shock-waves and turbulent dissipative layers is of considerable importance for many practical devices and has a wide range of engineering applications. Such phenomena occur almost inevitably in any transonic or supersonic flow and the subject has given rise to an important research effort since the advent of high speed fluid mechanics, more than forty years ago. However, with the coming of age of modern computers and the development of new sophisticated measurement techniques, considerable progress has been made in the field over the past fifteen years. The aim of the symposium was to provide an updated status of the research effort devoted to shear layer/shock-wave interactions and to present the most significant results obtained recently.