Skin Friction Drag Reduction by Compliant Coatings

Skin Friction Drag Reduction by Compliant Coatings
Author: Edward F. Blick
Publisher:
Total Pages: 29
Release: 1974
Genre:
ISBN:

Research on skin friction reduction by compliant coating conducted at the University of Oklahoma during the past eight years is reviewed. At the University of Oklahoma wind tunnel experiments showed that compliant coatings composed of a thin sheet of polyvinyl chloride covering either a thin layer of liquid or a thin layer of polyurethane foam reduced the turbulent skin friction drag by as much as 40% on flat plates. Hot wire anemometer measurements also indicated corresponding reductions in Reynolds stresses and turbulence intensities in the boundary layer. An NACA 0009 airfoil was found to have as much as 30% less drag when equipped with a 'polyvinyl chloride-polyurethane foam' compliant coating. (Author).

Turbulent Drag Reduction Using Compliant Coatings

Turbulent Drag Reduction Using Compliant Coatings
Author:
Publisher:
Total Pages: 0
Release: 2004
Genre:
ISBN:

The skin-friction drag of compliant coatings was measured using an axi-symmetric test model in a water tunnel for flow speed up to 4.5 m/s at the Reynolds number of 2.3 million. There were measurable drag reductions for up to 3% from three out of five compliant coatings tested. Only one coating showed a small drag increase, and the other had no change in drag. For all the tests, the 95% confidence level in measured drag reduction was 1% for flow velocities between 2.5 and 4.5 m/s. The error analysis suggested that the uncertainty was progressively increased with a reduction in flow velocity.

Boundary Layer Control-drag Reduction by Use of Compliant Coatings

Boundary Layer Control-drag Reduction by Use of Compliant Coatings
Author: F. W. PURYEAR
Publisher:
Total Pages: 14
Release: 1962
Genre:
ISBN:

Tests were conducted on 6 models of identical size to determine whether a reduction in drag could be obtained by the use of compliant coatings (trademarked Lamiflo) to stabilize a laminar boundary layer. Two noncompliant plastic models were manufactured. One was used as a standard for comparing the drag obtained on four models covered with various compliant coatings, and the other was instrumented with pressure taps in order to obtain body pressure measurements. None of the compliant bodies showed a drag reduction. The inability, during fabrication and testing, to maintain a faired transition from the metal nose adapter ring to the coating caused separation to occur at this discontinuity and probably turbulent flow to exist in an area designed to be laminar. Laminar flow on the forward portion of the coating is required if the coating is to stabilize the laminar boundary layer. (Author).

Transition and Turbulence Control

Transition and Turbulence Control
Author: Mohamed Gad-el-Hak
Publisher: World Scientific
Total Pages: 445
Release: 2006
Genre: Technology & Engineering
ISBN: 9812564705

This volume contains articles based on lectures given at the Workshop on Transition and Turbulence Control, hosted by the Institute for Mathematical Sciences, National University of Singapore, 8-10 December 2004. The lecturers included 13 of the world's foremost experts in the control of transitioning and turbulent flows. The chapters cover a wide range of subjects in the broad area of flow control, and will be useful to researchers working in this area in academia, government laboratories and industry. The coverage includes control theory, passive, active and reactive methods for controlling transitional and turbulent wall-bounded flows, noise suppression and mixing enhancement of supersonic turbulent jets, compliant coatings, modern flow diagnostic systems, and swept wing instabilities.

Flow Past Highly Compliant Boundaries and in Collapsible Tubes

Flow Past Highly Compliant Boundaries and in Collapsible Tubes
Author: Peter W. Carpenter
Publisher: Springer Science & Business Media
Total Pages: 326
Release: 2013-11-11
Genre: Science
ISBN: 9401704155

The IUTAM Symposium on Flow in Collapsible Tubes and Past Other Highly Compliant Boundaries was held on 26-30 March, 2001, at the University of Warwick. As this was the first scientific meeting of its kind we considered it important to mark the occasion by producing a book. Accordingly, at the end of the Symposium the Scientific Committee met to discuss the most appropriate format for the book. We wished to avoid the format of the conventional conference book consisting of a large number of short articles of varying quality. It was agreed that instead we should produce a limited number of rigorously refereed and edited articles by selected participants who would aim to sum up the state of the art in their particular research area. The outcome is the present book. Peter W. Ca rpenter, Warwick Timothy J. Pedley, Cambridge May, 2002. VB SCIENTIFIC COMMITTEE Co-Chair: P.W. Carpenter, Engineering, Warwiek, UK Co-Chair: TJ. Pedley, DAMTP, Cambridge, UK V.V. Babenko, Hydromechanics, Kiev, Ukraine R. Bannasch, Bionik & Evolutionstechnik, TU Berlin, Germany C.D. Bertram, Biomedical Engineering, New South Wales, Australia M. Gad-el-Hak, Aerospace & Mechanical Engineering, Notre Dame, USA J.B. Grotberg, Biomedical Engineering, Michigan, USA. R.D. Kamm, Mechanical Engineering, MIT, USA Y. Matsuzaki, Aerospace Engineering, N agoya, Japan P.K. Sen, Applied Mechanics, IIT Delhi, India L. van Wijngaarden, Twente, Netherlands K-S. Yeo, Mechanical Engineering, NU Singapore.

Report

Report
Author: United States. National Bureau of Standards
Publisher:
Total Pages: 696
Release: 1968
Genre: Hydraulic engineering
ISBN:

Boundary Layer Flow over Elastic Surfaces

Boundary Layer Flow over Elastic Surfaces
Author: Viktor V. Babenko
Publisher: Butterworth-Heinemann
Total Pages: 634
Release: 2012-09-29
Genre: Science
ISBN: 0123948215

While other methods of drag reduction are well-known in marine R&D and ship design environments worldwide, compliant coating drag reduction remains less well-known and poorly understood. This important book presents cutting-edge techniques and findings from research sources not generally accessible by Western researchers and engineers, aiding the application and further development of this potentially important technology. Beginning with an introduction to drag reduction that places the authors’ work on elastic surfaces and combined techniques in context, the book moves on to provide a comprehensive study of drag reduction through elastic coating with both flow and material properties considered. Coverage includes: Experimental findings around coherent vortical structures (CVS) in turbulent boundary layers and methods of controlling them Static and dynamic mechanical characteristics of elastic composite coatings, as well as new techniques and devices developed for their measurement Combined methods of flow control and drag reduction, including the effect of injection of polymer solutions, elastic coatings and generated longitudinal vortical structures on hydrodynamic resistance Intended as a reference for senior engineers and researchers concerned with the drag reduction and the dynamics of turbulent boundary layer flows, Boundary Layer Flow over Elastic Surfaces provides a unique source of information on compliant surface drag reduction and the experimental techniques around it that have shown measurable and repeatable improvements over recent years. This compilation of research findings and new techniques developed for measurement will aid R&D engineers, naval architects and senior designers in their quest to achieve drag reductions that will deliver significant efficiency savings. Unique source of information on compliant surface drag reduction—an important area of technology with practical application to ships—from otherwise inaccessible research studies Updates the knowledge-base on boundary layer flow and surface friction reduction, critical topics in the global quest for increased ship efficiency and fuel economy Reveals new techniques and devices developed for measurement and provides a comprehensive study of drag reduction through elastic coating with both flow and material properties covered