An experimental investigation of the turbulent boundary layer behind a forward facing step in supersonic flow

An experimental investigation of the turbulent boundary layer behind a forward facing step in supersonic flow
Author: Dave Robert Moore
Publisher:
Total Pages: 106
Release: 1958
Genre: Boundary layer
ISBN:

The report presents the results of an experimental study of the effect of a disturbance, produced by a forward facing step, on the turbulent boundary layer in compressible flow. Boundary layer total pressure surveys and direct skin friction measurements were made at six stations on each of two test surfaces. One surface was smooth and the other surface had an 0.080-inch forward facing step. The test stations were all located downstream of the step, the height of which was approximately one-half the smooth surface boundary layer thickness. Data were obtained at Mach Numbers of 2.0, 2.5, 3.0, and 3.5 and the test Reynolds Numbers, based on momentum thickness, ranged from 8,000 to 10,000 approximately. The results of this investigation indicate that the effect of the disturbance, produced by the step on the 'law of the wall' and 'velocity defect law' profiles appears to be negligible from a point approximately 10 flat plate boundary layer thicknesses downstream from the step. (Author).

Experimental Investigation of Turbulent Boundary Layer with Uniform Blowing at Moderate and High Reynolds Numbers

Experimental Investigation of Turbulent Boundary Layer with Uniform Blowing at Moderate and High Reynolds Numbers
Author: Gazi Hasanuzzaman
Publisher: Cuvillier Verlag
Total Pages: 180
Release: 2022-01-18
Genre: Technology & Engineering
ISBN: 3736965583

Experimental investigation in turbulent boundary layer flows represents one of the canonical geometries of wall bounded shear flows. Utmost relevance of such experiments, however, is applied in the engineering applications in aerospace and marine industries. In particular, continuous effort is being imparted to explore the underlying physics of the flow in order to develop models for numerical tools and to achieve flow control. Flow control experiments have been widely investigated since 1930’s. Several flow control technique has been explored and have shown potential benefit. But the choice of control technique depends largely on the boundary condition and the type of application. Hence, friction drag of subsonic transport aircraft is intended to be reduced within the scope of this Ph. D. topic. Therefore, application of active control method such as microblowing effect in the incompressible, zero pressure gradient turbulent boundary layer was investigated. A series of experiments have been performed in two different wind tunnel facilities. Wind tunnel from Department of Aerodynamics and Fluid Mechanics (LAS) was used for the measurements for moderate Reynolds number range in co-operation with the wind tunnel from Laboratoire de M´ecanique de Feiret Lille for large Reynolds number range. Measurements are conducted with the help of state-of-the-art techniques such as Laser Doppler Anemometry, Particle Image Velocimetry and electronic pressure sensors.

Experimental Study on High Subsonic Turbulent Flow Incipient Separation

Experimental Study on High Subsonic Turbulent Flow Incipient Separation
Author: Jain-Ming Wu
Publisher:
Total Pages: 68
Release: 1976
Genre: Aerodynamics
ISBN:

For flow over a two-dimensional ramp compression corner case, an experimental investigation to determine the incipient separation was carried out at Mach numbers between 0.55 and 0.9 and Reynolds numbers (based on undisturbed boundary layer thickness) between 350,000 and 690,000. Detailed surface pressure, pitot traversing and oil flow data were obtained for each ramp angle case. Two-dimensionality of the ramp compression corners was verified by the surface oil flow. A major finding of this study is that the incipient separation ramp angle is relatively independent of Mach number and Reynolds number within the range studied. The incipient separation ramp angle was found to be about 22.5 degrees.

Analysis of Turbulent Boundary Layers

Analysis of Turbulent Boundary Layers
Author: Tuncer Cebeci
Publisher: Elsevier
Total Pages: 423
Release: 2012-12-02
Genre: Technology & Engineering
ISBN: 0323151051

Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.