Author: William Henry Mason
Publisher:
ISBN:
Category :
Languages : en
Pages : 526

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Author: W. H. Mason
Publisher:
ISBN:
Category : Aerodynamics, Transonic
Languages : en
Pages : 275

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Book Description
Advances in inviscid transonic flow field computational capability and supercritical airfoil design make it important to understand of the the physics of normal shock-boundary layer interactions. In this work, the Navier-Stokes equations are thoroughly investigated through the use of perturbation methods and a generalized multi-region model is proposed for interactions between weak normal shock waves and turbulent boundary layers. This model is first applied to a highly idealized case in which a uniform subsonic flow is used to model the boundary layer, and analytic results for the wall and interface pressure are obtained.

Author: Hideaki Ogawa
Publisher:
ISBN:
Category :
Languages : en
Pages :

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

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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: M. C. Alstatatt
Publisher:
ISBN:
Category : Aerodynamics, Transonic
Languages : en
Pages : 42

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Book Description
Two wind tunnel tests were conducted in a flow exhibiting a shock-wave/boundary-layer interaction of the type occurring on airfoils at transonic velocities. Boundary-layer pressure distributions were measured with pitot and static probes. Velocities in the free stream and in the boundary layer were obtained with a laser velocimeter (LV) system, and a data reduction program for the LV results was developed. Measurements from the pressure probes and from the LV system are compared with each other and with theoretical computations. It was found that the analytic models for boundary-layer velocity profile and Reynolds stress agree well with experimental measurements. (Author).

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Two wind tunnel tests were conducted in a flow exhibiting a shock-wave/boundary-layer interaction of the type occurring on airfoils at transonic velocities. Boundary-layer pressure distributions were measured with pitot and static probes. Velocities in the free stream and in the boundary layer were obtained with a laser velocimeter (LV) system, and a data reduction program for the LV results was developed. Measurements from the pressure probes and from the LV system are compared with each other and with theoretical computations. It was found that the analytic models for boundary-layer velocity profile and Reynolds stress agree well with experimental measurements. (Author).

Author: D. V. Roscoe
Publisher:
ISBN:
Category :
Languages : en
Pages : 89

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Book Description
The present report discusses the development of a time-dependent Navier-Stokes code for use in predicting transonic shock-wave boundary layer interaction. In addition, various test cases which have been performed are discussed. The algorithm used to solve the equations is based upon the consistently split linearized block implicit method of Briley and McDonald (15, 16). The philosophy and use of a solution adaptive mesh is also described. The test cases studied in this report are: normal shock wave boundary layer interaction in a constant area circular pipe, steady transonic flow over an axisymmetric bump, unsteady flow over an axisymmetric bump, supersonic flow over an axisymmetric compression corner and oblique shock wave impingement on a flat plate boundary layer. (Author).

Author: Fulvio Sartor
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
A transonic interaction between a shock wave and a turbulent boundary layer is experimentally and theoretically investigated. The configuration is a channel flow over a bump, where a shock wave causes the separation of the boundary layer and a recirculating bubble is observed downstream of the shock foot.The mean flow is experimentally investigated by means of PIV, then different techniques allows to identify the main unsteadiness of this shock-wave/boundary-layer interaction. As recognised in similar configurations, the flow presents two distinguished characteristic frequencies, whose origins are still unknown.Numerical simulations are performed solving RANS equations. Results are in good agreement with the experimental mean flow, but the approach fails to predict the unsteady. The solution of RANS equations is then considered as a base flow, and a global stability analysis is performed. Eigenvalue decomposition of the Navier-Stokes operator indicates that the interaction is stable, and the dynamics cannot be described by unstable global modes.A linearised approach based on a singular-value decomposition of the Resolvent is then proposed: the noise-amplifier behaviour of the flow is highlighted by the linearised approach. Medium-frequency perturbations are shown to be the most amplified in the mixing layer, whilst the shock wave behaves as a low-pass filter.The same approach is then applied to a transonic flow over a profile, where the flow can present high-amplitude shock oscillations. The stability analysis can describe both the buffet phenomenon when an unstable mode is present, and the convective instabilities responsible of medium-frequency unsteadiness.

Author: Jones F. Cahill
Publisher:
ISBN:
Category :
Languages : en
Pages : 75

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Book Description
A flight test investigation was made using a Lockheed C-141 airplane to obtain data related to scale effects on transonic shock-boundary layer interactions. The primary measurements consisted of wing surface chordwise pressure distributions at three spanwise stations, and boundary layer profiles for three chordwise positions at one spanwise station. Volume I contains the data analysis and discussions of the test results. Results obtained, when compared with previously available wind tunnel data, showed that large scale effects on chordwise pressure distribution can occur with turbulent boundary layers on a wing having small Mach number gradients forward of the shock. A shock-induced separation, followed by flow reattachment, was shown to occur when the shock pressure rise reached a value approximately equal to that indicated in NACA Report 1356. For wing sections of the type used on the C-141, scale effects on buffet phenomena should be anticipated also. (Author).

Author: Hans Wolfgang Liepmann
Publisher:
ISBN:
Category :
Languages : en
Pages : 33

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