Boundary-layer displacement and leading edge bluntness effects on attached and separated laminar boundary layers in a compression corner. I - Theoretical study

New solutions are presented for non-stationary boundary layers induced by planar, cylindrical and spherical Chapman-Jouguet (C-J) detonation waves. The numerical results show that the Prandtl number ( Pr ) has a very significant influence on the boundary-layer-flow structure. A comparison with available time-dependent heat-transfer measurements in a planar geometry in a 2H 2 + O 2 mixture shows much better agreement with the present analysis than has been obtained previously by others. This lends confidence to the new results on boundary layers induced by cylindrical and spherical detonation waves. Only the spherical-flow analysis is given here in detail for brevity.

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Effects of Curvature on Laminar Boundary Layers in Sink-Type Flows

Journal of Basic Engineering ◽

10.1115/1.3571115 ◽

1969 ◽

Vol 91 (3) ◽

pp. 353-358 ◽

Cited By ~ 5

Author(s):

W. A. Gustafson ◽

I. Pelech

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Momentum Equation ◽

Similarity Solutions ◽

Momentum Thickness ◽

Two Dimensional ◽

Thickness Increase ◽

Laminar Boundary Layers ◽

Converging Channel ◽

Special Case

The two-dimensional, incompressible laminar boundary layer on a strongly curved wall in a converging channel is investigated for the special case of potential velocity inversely proportional to the distance along the wall. Similarity solutions of the momentum equation are obtained by two different methods and the differences between the methods are discussed. The numerical results show that displacement and momentum thickness increase linearly with curvature while skin friction decreases linearly.

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A Reference Temperature Method for Compressible Laminar Boundary Layers

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-1973-0030 ◽

1973 ◽

Vol 2 (4) ◽

pp. 201-204

Author(s):

R. Camarero

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Wall Temperature ◽

Reference Temperature ◽

Integral Approach ◽

Pressure Gradients ◽

Two Dimensional ◽

Laminar Boundary Layers ◽

Temperature Method ◽

Compressibility Effects

A calculation procedure for the solution of two-dimensional and axi-symmetric laminar boundary layers in compressible flow has been developed. The method is an extension of the integral approach of Tani to include compressibility effects by means of a reference temperature. Arbitrary pressure gradients and wall temperature can be specified. Comparisons with experiments obtained for supersonic flows over a flat plate indicate that the method yields adequate results. The method is then applied to the solution of the boundary layer on a Basemann inlet.

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A Method for the Calculation of 3D Boundary Layers on Practical Wing Configurations

Journal of Fluids Engineering ◽

10.1115/1.3240755 ◽

1981 ◽

Vol 103 (1) ◽

pp. 104-111 ◽

Cited By ~ 5

Author(s):

J. P. F. Lindhout ◽

G. Moek ◽

E. De Boer ◽

B. Van Den Berg

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Boundary Layer Flow ◽

Eddy Viscosity ◽

Separated Flow ◽

Laminar Boundary Layers ◽

Eddy Viscosity Model ◽

Airplane Wing ◽

Turbulent Boundary Layer Flow ◽

Layer Flow

This paper gives a description of a calculation method for 3D turbulent and laminar boundary layers on nondevelopable surfaces. A simple eddy viscosity model is incorporated in the method. Special attention is given to the organization of the computations to circumvent as much as possible stepsize limitations. The method is also able to proceed the computation around separated flow regions. The method has been applied to the laminar boundary layer flow over a flat plate with attached cylinder, and to a turbulent boundary layer flow over an airplane wing.

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Criteria for Boundary Layer Transition

Volume 5: Heat Transfer, Parts A and B ◽

10.1115/gt2011-45110 ◽

2011 ◽

Author(s):

Stefan Becker ◽

Donald M. McEligot ◽

Edmond Walsh ◽

Eckart Laurien

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Boundary Layer Flow ◽

Leading Edge ◽

Boundary Layer Transition ◽

Turbulence Level ◽

Two Dimensional ◽

Freestream Turbulence ◽

Layer Transition ◽

Layer Flow

New results are deduced to assess the validity of proposed transition indicators when applied to situations other than boundary layers on smooth surfaces. The geometry employed utilizes a two-dimensional square rib to disrupt the boundary layer flow. The objective is to determine whether some available criteria are consistent with the present measurements of laminar recovery and transition for the flow downstream of this rib. For the present data — the proposed values of thresholds for transition in existing literature that are based on the freestream turbulence level at the leading edge are not reached in the recovering laminar run but they are not exceeded in the transitioning run either. Of the pointwise proposals examined, values of the suggested quantity were consistent for three of the criteria; that is, they were less than the threshold in laminar recovery and greater than it in the transitioning case.

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Boundary layer development after a separated region

Journal of Fluid Mechanics ◽

10.1017/s0022112098002420 ◽

1998 ◽

Vol 374 ◽

pp. 91-116 ◽

Cited By ~ 55

Author(s):

IAN P. CASTRO ◽

ELEANORA EPIK

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Free Stream ◽

Turbulence Models ◽

Separated Flow ◽

Leading Edge ◽

Turbulence Structure ◽

Outer Flow ◽

Free Stream Turbulence ◽

Layer Region

Measurements obtained in boundary layers developing downstream of the highly turbulent, separated flow generated at the leading edge of a blunt flat plate are presented. Two cases are considered: first, when there is only very low (wind tunnel) turbulence present in the free-stream flow and, second, when roughly isotropic, homogeneous turbulence is introduced. With conditions adjusted to ensure that the separated region was of the same length in both cases, the flow around reattachment was significantly different and subsequent differences in the development rate of the two boundary layers are identified. The paper complements, but is much more extensive than, the earlier presentation of some of the basic data (Castro & Epik 1996), confirming not only that the development process is very slow, but also that it is non-monotonic. Turbulence stress levels fall below those typical of zero-pressure-gradient boundary layers and, in many ways, the boundary layer has features similar to those found in standard boundary layers perturbed by free-stream turbulence. It is argued that, at least as far as the turbulence structure is concerned, the inner layer region develops no more quickly than does the outer flow and it is the latter which essentially determines the overall rate of development of the whole flow. Some numerical computations are used to assess the extent to which current turbulence models are adequate for such flows.

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