Effect of pressure gradients on the stability of three-dimensional boundary layers

This paper describes a floating-element skin friction meter which has been designed for use in adverse pressure gradients. The effects of secondary forces on the element, which arise from the pressure gradient, are examined in some detail. The limitations of various methods of measuring wall shear stress are discussed and the results from the floating element device are compared with measurements taken in a two-dimensional boundary layer using Preston tubes and velocity profiles. As it is planned to use the instrument later for direct measurements of the shear stress in three-dimensional boundary layers, the relevance of the instrument to this situation is also discussed.

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Transition prediction for three-dimensional boundary layers in computational fluid dynamics applications

AIAA Journal ◽

10.2514/3.15228 ◽

2002 ◽

Vol 40 ◽

pp. 1536-1541

Author(s):

J. D. Crouch ◽

I. W. M. Crouch ◽

L. Ng

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Boundary Layers ◽

Three Dimensional ◽

Transition Prediction ◽

Dimensional Boundary

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Effects of Three-Dimensional Pressure Gradients on High-Speed Turbulent Boundary Layers

AIAA Scitech 2021 Forum ◽

10.2514/6.2021-0913 ◽

2021 ◽

Author(s):

Scott J. Peltier ◽

Brian E. Rice ◽

Ethan Johnson ◽

Venkateswaran Narayanaswamy ◽

Marvin E. Sellers

Keyword(s):

Boundary Layers ◽

High Speed ◽

Three Dimensional ◽

Turbulent Boundary Layers ◽

Pressure Gradients

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

Siberian Journal of Physics ◽

10.54362/1818-7919-2008-3-3-34-38 ◽

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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Review: Laminar-to-Turbulent Transition of Three-Dimensional Boundary Layers on Rotating Bodies

Journal of Fluids Engineering ◽

10.1115/1.2910255 ◽

1994 ◽

Vol 116 (2) ◽

pp. 200-211 ◽

Cited By ~ 17

Author(s):

Ryoji Kobayashi

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Three Dimensional ◽

Speed Ratio ◽

Stream Velocity ◽

Turbulent Transition ◽

Centrifugal Instability ◽

Crossflow Instability ◽

Dimensional Boundary ◽

Axisymmetric Bodies

The laminar-turbulent transition of three-dimensional boundary layers is critically reviewed for some typical axisymmetric bodies rotating in still fluid or in axial flow. The flow structures of the transition regions are visualized. The transition phenomena are driven by the compound of the Tollmien-Schlichting instability, the crossflow instability, and the centrifugal instability. Experimental evidence is provided relating the critical and transition Reynolds numbers, defined in terms of the local velocity and the boundary layer momentum thickness, to the local rotational speed ratio, defined as the ratio of the circumferential speed to the free-stream velocity at the outer edge of the boundary layer, for the rotating disk, the rotating cone, the rotating sphere and other rotating axisymmetric bodies. It is shown that the cross-sectional structure of spiral vortices appearing in the transition regions and the flow pattern of the following secondary instability in the case of the crossflow instability are clearly different than those in the case of the centrifugal instability.

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