Propagation of perturbations in the three-dimensional boundary layer on a delta wing in the viscid-inviscid interaction regime

2010 ◽  
Vol 45 (3) ◽  
pp. 422-433
Author(s):  
G. N. Dudin ◽  
K. T. M’int
Keyword(s):  
Boundary Layer ◽  
Delta Wing ◽  
Three Dimensional ◽  
Dimensional Boundary ◽  
Interaction Regime

Singularities associated with separating boundary layers

1965 ◽  
Vol 257 (1084) ◽  
pp. 409-444 ◽  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Delta Wing ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Separation Line ◽  
Two Dimensional Flow ◽  
Dimensional Boundary ◽  
Line Of Singularities ◽  
Appl Math

This paper investigates the nature of flow in the neighbourhood of separation of a laminar boundary layer, and is based on the work of Goldstein (1948 Quart. J. Mech. Appl. Math. 1, 43), Stewartson (1958 Quart. J. Mech. Appl. Math. 11, 399), Terrill (1960 Phil. Trans. A, 253, 55) and Stewartson (1962 J.Fluid Mech. 12, 117). The problem of establishing the existence or nonexistence of a singularity at separation for incompressible two-dimensional flow is investigated in the first three of these papers, and the last mentioned finds that if heat transfer across the boundary is permitted no singularity occurs at a point of vanishing skin friction unless the heat transfer is also zero at this point. The present work examines the possibility of the non-occurrence of singularities in other physical situations including reference to three-dimensional separation. Particular problems considered include that of conefield flow of an incompressible fluid over a delta wing for which the separation line is shown to be a line of singularities, and that of compressible flow over a yawed cylinder in which case the conclusion is that the separation line is a line of regular points if the heat transfer is non-zero along its length. The problem of separation for a general three-dimensional boundary layer is considered but not resolved.

An Assessment of Three-Dimensional Turbulent Boundary Layer Prediction Methods

1973 ◽  
Vol 95 (3) ◽  
pp. 415-421 ◽  
Author(s):  
A. J. Wheeler ◽  
J. P. Johnston
Keyword(s):  
Boundary Layer ◽  
Eddy Viscosity ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Boundary Layer Flows ◽  
Mean Velocity ◽  
Eddy Viscosity Model ◽  
Separating Flow ◽  
Dimensional Boundary ◽  
Stress Models

Predictions have been made for a variety of experimental three-dimensional boundary layer flows with a single finite difference method which was used with three different turbulent stress models: (i) an eddy viscosity model, (ii) the “Nash” model, and (iii) the “Bradshaw” model. For many purposes, even the simplest stress model (eddy viscosity) was adequate to predict the mean velocity field. On the other hand, the profile of shear stress direction was not correctly predicted in one case by any model tested. The high sensitivity of the predicted results to free stream pressure gradient in separating flow cases is demonstrated.

Experimental and Theoretical Investigation of the Supersonic Boundary Layer Stability on the Swept Wing

2008 ◽  
Vol 3 (3) ◽  
pp. 34-38
Author(s):  
Sergey A. Gaponov ◽  
Yuri G. Yermolaev ◽  
Aleksandr D. Kosinov ◽  
Nikolay V. Semionov ◽  
Boris V. Smorodsky
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Leading Edge ◽  
Supersonic Boundary Layer ◽  
Mean Flow ◽  
Swept Wing ◽  
Wing Model ◽  
Dimensional Boundary ◽  
The Stability ◽  
Good Agreement

Theoretical and an experimental research results of the disturbances development in a swept wing boundary layer are presented at Mach number М = 2. In experiments development of natural and small amplitude controllable disturbances downstream was studied. Experiments were carried out on a swept wing model with a lenticular profile at a zero attack angle. The swept angle of a leading edge was 40°. Wave parameters of moving disturbances were determined. In frames of the linear theory and an approach of the local self-similar mean flow the stability of a compressible three-dimensional boundary layer is studied. Good agreement of the theory with experimental results for transversal scales of unstable vertices of the secondary flow was obtained. However the calculated amplification rates differ from measured values considerably. This disagreement is explained by the nonlinear processes observed in experiment

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