Wind Tunnel Experiments on Turbulent Boundary Layer Flows

Wind Tunnel Experiments on Turbulent Boundary Layer Flows

Author: Adri√°n R. Wittwer

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

The knowledge and experimental development of boundary layer turbulent flows is extremely important in applications related to the building aerodynamics, wind comfort, atmospheric dispersion, and even aeronautics. The Aerodynamic Laboratories of the UFRGS and UNNE have been making joint activities related to wind engineering such as those mentioned earlier for more than 25 years. In this work, a compilation of different experiments on turbulent boundary layer flows realized in these both laboratories is carried out. The characteristics of flows that develop on a smooth surface of the wind tunnel are experimentally evaluated. Then, reduced-scale models of atmospheric boundary layer flows are analyzed including the effects of turbulence generators and surface roughness. Special attention on the behavior of the turbulent parameters in the case of experimental studies using low mean velocity is paid. Finally, some comments referring to recent studies on thermal effects in turbulent boundary layer flows and the development of reduced-scale models of convective flows are included.


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

Published: 2022-01-18

Total Pages: 180

ISBN-13: 3736965583

DOWNLOAD EBOOK

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.


Wind Tunnels and Experimental Fluid Dynamics Research

Wind Tunnels and Experimental Fluid Dynamics Research

Author: Jorge Colman Lerner

Publisher: BoD – Books on Demand

Published: 2011-07-27

Total Pages: 728

ISBN-13: 9533076232

DOWNLOAD EBOOK

The book "Wind Tunnels and Experimental Fluid Dynamics Research" is comprised of 33 chapters divided in five sections. The first 12 chapters discuss wind tunnel facilities and experiments in incompressible flow, while the next seven chapters deal with building dynamics, flow control and fluid mechanics. Third section of the book is dedicated to chapters discussing aerodynamic field measurements and real full scale analysis (chapters 20-22). Chapters in the last two sections deal with turbulent structure analysis (chapters 23-25) and wind tunnels in compressible flow (chapters 26-33). Contributions from a large number of international experts make this publication a highly valuable resource in wind tunnels and fluid dynamics field of research.


Wind Tunnels and Experimental Fluid Dynamics Research

Wind Tunnels and Experimental Fluid Dynamics Research

Author: Jorge Colman Lerner

Publisher: IntechOpen

Published: 2011-07-27

Total Pages: 726

ISBN-13: 9789533076232

DOWNLOAD EBOOK

The book "Wind Tunnels and Experimental Fluid Dynamics Research" is comprised of 33 chapters divided in five sections. The first 12 chapters discuss wind tunnel facilities and experiments in incompressible flow, while the next seven chapters deal with building dynamics, flow control and fluid mechanics. Third section of the book is dedicated to chapters discussing aerodynamic field measurements and real full scale analysis (chapters 20-22). Chapters in the last two sections deal with turbulent structure analysis (chapters 23-25) and wind tunnels in compressible flow (chapters 26-33). Contributions from a large number of international experts make this publication a highly valuable resource in wind tunnels and fluid dynamics field of research.


A Compilation of Unsteady Turbulent Boundary Layer Experimental Data

A Compilation of Unsteady Turbulent Boundary Layer Experimental Data

Author: Lawrence W. Carr

Publisher:

Published: 1981

Total Pages: 62

ISBN-13:

DOWNLOAD EBOOK

A comprehensive literature search was conducted and those experiments related to unsteady turbulent boundary-layer behavior were cataloged. In addition, an international survey of industrial, university, and government research laboratories was made, in which new and ongoing experimental programs associated with unsteady turbulent boundary-layer research were identified. Pertinent references were reviewed and classified based on the technical emphasis of the various experiments that include instantaneous or ensemble-averaged profiles of boundary-layer variables are stressed. Detailed reviews that include descriptions of the experimental apparatus, flow conditions, summaries of acquired data, and significant conclusions are made. The measurements made in these experiments that exist in digital form have been stored on magnetic tape, and instructions are presented for accessing these data sets for further analysis. (Author).


Wind Tunnel Measurements of the Mean Flow in the Turbulent Boundary Layer and Wake in the Region of the Trailing Edge of a Swept Wing at Subsonic Speeds

Wind Tunnel Measurements of the Mean Flow in the Turbulent Boundary Layer and Wake in the Region of the Trailing Edge of a Swept Wing at Subsonic Speeds

Author: P. H. Cook

Publisher:

Published: 1979

Total Pages: 186

ISBN-13:

DOWNLOAD EBOOK

Measurements have been made of the distributions of local Mach number, flow direction and static pressure coefficient through the wake and boundary layers of a wing of constant chord (0.61 m normal to the leading edge) and the RAE 101 section at sweep angles of 20 and 28 degrees. The model spanned the 1.8 m (6 ft) dimension of the wind tunnel working section and was set at incidences in the range of + or - 1.88 degrees. Tests were made at free stream Mach numbers in the range 0.43 to 0.76 and Reynolds of 7 to 11 x 10 to the 6th power. The technique of measurement, using calibrated miniature three-hole yawmeters, is described and the experimental results are compared with an integral boundary-layer calculation method. Some comparisons are also made with previous tests at zero sweepback. (Author).


Evaluation of a Technique to Generate Artificially Thickened Boundary Layers in Supersonic and Hypersonic Flows

Evaluation of a Technique to Generate Artificially Thickened Boundary Layers in Supersonic and Hypersonic Flows

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-08-20

Total Pages: 30

ISBN-13: 9781722210540

DOWNLOAD EBOOK

The feasibility of using a contoured honeycomb model to generate a thick boundary layer in high-speed, compressible flow was investigated. The contour of the honeycomb was tailored to selectively remove momentum in a minimum of streamwise distance to create an artificially thickened turbulent boundary layer. Three wind tunnel experiments were conducted to verify the concept. Results indicate that this technique is a viable concept, especially for high-speed inlet testing applications. In addition, the compactness of the honeycomb boundary layer simulator allows relatively easy integration into existing wind tunnel model hardware. Porro, A. R. and Hingst, W. R. and Davis, D. O. and Blair, A. B., Jr. Glenn Research Center; Langley Research Center RTOP 505-80-21...


Analysis of Turbulent Boundary Layers

Analysis of Turbulent Boundary Layers

Author: Tuncer Cebeci

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 423

ISBN-13: 0323151051

DOWNLOAD EBOOK

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.


A High-lift Building Block Flow

A High-lift Building Block Flow

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-08-27

Total Pages: 36

ISBN-13: 9781726151153

DOWNLOAD EBOOK

Experimental evidence exists which suggests turbulent boundary layer relaminarization may play an important role in the inverse Reynolds number effect in high-lift systems. An experimental investigation of turbulent boundary layer relaminarization has been undertaken at the University of Notre Dame's Hessert Center for Aerospace Research in cooperation with NASA Dryden Flight Research Center. A wind tunnel facility has been constructed at the Hessert Center and relaminarization achieved. Preliminary evidence suggests the current predictive tools available are inadequate at determining the onset of relaminarization. In addition, an in-flight relaminarization experiment for the NASA Dryden FTF-II has been designed to explore relaminarization at Mach and Reynolds numbers more typical of commercial high-lift systems.Bourassa, Corey and Thomas, Flint O. and Nelson, Robert C.Armstrong Flight Research CenterMACH NUMBER; REYNOLDS NUMBER; TURBULENT BOUNDARY LAYER; WIND TUNNELS; PREDICTIONS; EXPERIMENTATION...