DOCSLIB.ORG

Investigation of Boundary Layer Suction on a Wind Turbine Airfoil Using CFD

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Investigation of Boundary Layer Suction on a Wind Turbine Airfoil Using CFD Author: Apostolos Tentolouris Piperas Investigation of Boundary Layer Suction on a Wind Turbine Airfoil using CFD Supervisor: Martin O.L. Hansen Wind Energy Building 403 Kongens Lyngby Master’s Thesis 5th August 2010 Acknowledgements There is not much to acknowledge really. People without whom I would never have survived my studies and who helped me realize that there is plenty of beauty to be shared despite the smothering workload of these past two years, a period that eventually lead to the present document, do not need this page to be aware of it and most likely will never read it in the first place. I would like however to express my gratitude to my supervisor Martin O.L. Hansen, probably the smartest person on the planet, for taking the time to bother with me and my questions, and Dalibor Cavar with Juan Pablo Murcia without whom my work would have taken twice the time and effort. Finally, I would like to thank whoever was responsible for my admittance to DTU. I may not have become a better engineer in the direction I was hoping, but I ended up becoming a better person, which is something I could have never hoped for. i Preface This report is part of the requirements to achieve the Master of Science in Engineering (M.Sc.Eng.) at the Technical University of Denmark. It represents 30 ECTS points and was carried out at the Department of Mechanical Engineering at the Technical University of Denmark from Fe- bruary until August 2010. iii Abstract The present Master Thesis deals with the investigation of suction as a mean of boundary layer control on a wind turbine root airfoil using CFD. Flow around a NACA 4415 airfoil is simula- ted in ANSYS CFX 12.1 environment and transition to turbulence as well as flow separation are studied for various arrangements of suction. The coefficients of lift and drag are computed for different angles of attack and the lift and drag curves after applying suction are compared with the corresponding values of the clean airfoil. Finally, a simplistic analysis is carried out in order to evaluate the impact and the usability of boundary layer suction on a wind turbine blade. v Table of Contents List of Figures xi List of Symbols 1 1 Introduction 1 1.1 General . ................................... 1 1.2 Previous Work .................................. 1 1.3 Scope . ................................... 2 2 Boundary Layer Theory 3 2.1 Boundary Layer Basics ............................. 3 2.2 Laminar and Turbulent flows.......................... 5 2.3 Boundary Layer Thickness - Drag ....................... 7 2.4 Transition . ................................... 10 2.5 External Pressure Gradient . ........................ 14 2.6 Boundary Layer Separation . ........................ 15 2.7 Separation Bubbles . ............................. 17 2.8 Boundary Layer Control ............................ 18 2.9 Boundary Layer Suction ............................ 21 3 CFD Implementation 25 3.1 Setting up the model . ............................. 25 3.1.1 Geometry . ............................. 25 3.1.2 Mesh .................................. 25 3.1.3 Setup .................................. 27 3.1.4 Solver .................................. 30 4 Results 37 4.1 Suction Location . ............................. 38 4.2 Discrete Suction versus Distributed Suction . 39 4.3 Suction Quantity . ............................. 45 4.4 Finer Analysis .................................. 47 4.5 Wind Turbine Performance Enhancement . 51 vii viii TABLE OF CONTENTS 4.5.1 Blade Element Momentum Method . 52 4.5.2 BEM algorithm . ............................ 52 4.5.3 BEM results . ............................ 55 4.6 The Blade as a Centrifugal Pump . ...................... 59 5 Conclusions and Perspectives 63 5.1 Conclusions . ................................. 63 5.2 Suggestions for Further Work .......................... 63 A Appendix 69 List of Figures 2.1 Boundary layer development. ........................ 4 2.2 Thickness and shear variation . ........................ 5 2.3 Laminar and turbulent non-dimensionalised velocity profile. 6 2.4 Turbulent boundary layer profile. 6 2.5 Turbulent boundary layer structure. ....................... 7 2.6 Diplacement thickness. ............................. 8 2.7 Boundary layer thicknesses. ........................ 9 2.8 Shear stress coefficient. ............................. 9 2.9 Shear stress distribution. ............................ 10 2.10 Transition from laminar flow to turbulent. 11 2.11 Tollmien Schlichting waves. ........................ 11 2.12 Ribbon frequency effect on boundary layer response. 12 2.13 Neutral Stability Curve. ............................. 13 2.14 Pressure distribution on an airfoil. ....................... 13 2.15 Effect of pressure gradient on boundary layer. 14 2.16 Velocity profiles and gradients. ........................ 15 2.17 Boundarly layer profiles and point of inflection. 16 2.18 Flow separation on an airfoil. ........................ 16 2.19 Effect of adverse pressure gradient on the boundary layer. 17 2.20 Separation bubbles. ............................. 18 2.21 Vortex generators. ............................. 20 2.22 Boundary layer aceleration. ........................ 20 2.23 Boundary layer control via suction. ....................... 21 2.24 Comparison between continuous and discrete suction. 22 2.25 Critical value of suction coefficient. ...................... 22 2.26 Skin friction variation under optimum suction . 23 3.1 Relative error. .................................. 26 3.2 Generated Mesh. ............................. 29 3.3 Image of the domain for the LE suction case prior the import into the Solver.. 30 3.4 No suction for 0 degrees angle of attack. 31 3.5 No suction for 15 degrees angle of attack. 33 ix x LIST OF FIGURES 3.6 Transient simulation for no suction case at 15 degrees angle of attack. 33 3.7 Leading edge distributed suction (Cq = 0.03) for 15 degrees angle of attack. 34 3.8 Leading edge distribution - Tight convergence, higher number of iterrations . 34 3.9 Transient simulation for (Cq = 0.03) at 15 degrees angle of attack . 35 4.1 Eddy viscosity for 10o angle of attack ..................... 37 4.2 Point of transition ................................ 38 4.3 Non dimensionalized eddy viscosity and shear stress . 39 4.4 Application of suction at maximum thickness point and at leading edge . 40 4.5 Point of transition to turbulent flow at different angles of attack . 41 4.6 Location of distributed suction . ...................... 41 4.7 Velocity gradient for clean airfoil and distributes suction . 42 4.8 Flow separation at 17o angle of attack for a clean airfoil. 42 4.9 Pressure coefficients for different angles of attack . 43 4.10 Pressure coefficient at 17o angle of attack for different suction cases. 43 4.11 Flow separation for different distributed suction cases . 44 4.12 Lift and drag curves for discrete suction . 45 4.13 Lift and drag curves for distributed suction . 45 o 4.14 CLand CD values for different suction coefficients at 15 angle of attack . 46 4.15 CL ratio for different suction coefficients at 15o angle of attack . 46 CD 4.16 Pressure coefficient for different suction coefficients at 15o angle of attack . 47 4.17 Eddy viscosity for different suction coefficients at 15o angle of attack . 47 du o 4.18 Velocity gradient dy for different suction coefficients at 15 angle of attack . 50 4.19 Streamlines for different suction coefficients at 15o angle of attack . 50 4.20 Lift coefficient response for different angles of attack . 50 4.21 Lift and drag curves for the clean airfoil and Cq = 0.08 case . 51 4.22 Suction effect on aerodynamic coefficients . 51 4.23 Velocities at rotor plane. ............................ 52 4.24 Tjaereborg wind turbine characteristics ..................... 55 4.25 Angle of attack variation ............................ 56 4.26 Chord distribution of the Tjaereborg blade . 56 4.27 Lift and drag curves of root segment ...................... 57 4.28 Power contribution of each of the three first segments . 58 4.29 Power curve of the Tjaereborg wind turbine after suction . 58 4.30 Power ratio between the clean blade and suction cases . 59 4.31 Weibull distribution with A = 8 and k = 2................... 59 4.32 Power contribution of each of the two close to hub segments for reduced chord 60 4.33 Tjaereborg power curve after suction and 25%chord reduction . 60 4.34 Tjaereborg power coefficient curve after suction and 25%chord reduction . 61 4.35 Thrust on the rotor for a range of wind speeds from cut-in speed to rated power 61 5.1 Mass flow distribution at suction location. 64 LIST OF FIGURES xi A.1 Distributed suction location . ........................ 69 A.2 Eddy viscosity for different turbulence models. 70 A.3 Eddy viscosity for normal and 45o inclined suction for different angles of attack 71 A.4 Sensitivity check for steady state simulations . 72 A.5 FFT of lift coefficient response. ........................ 72 A.6 Lift coefficient response at 60o angle of attack. 73 A.7 Suction arrangement for pump driven suction on a glider plane . 73 List of Symbols a .................................................axial induction coefficient [] a! ............................................tangential induction coefficient [] A .............................................................rotor area [m 2] AEO................................................annual energy output [GWh] CD ..........................................................drag coefficient [] C fx ...............................................local shear stress coefficient [] C fL ...........................................averaged
Load more

Recommended publications
  • 1 Adaptive Wing Technology, Aeroelasticity
    Adaptive wing technology, aeroelasticity and flight stability: The lessons from natural flight Dr. Pascual Marqués-Bruna, Faculty of Arts & Sciences, Edge Hill University, St. Helen’s Road, Ormskirk, L39 4QP, United Kingdom. [email protected] Elena Spiridon, School of Natural Sciences and Psychology, Liverpool John Moores University, Tom Reilly Building, Byrom Street, Liverpool, L3 3AF, United Kingdom. [email protected] Abstract This paper reviews adaptive wing morphology and biophysics observed in the natural world and the equivalent adaptive wing technology, aeroelasticity and flight stability principles used in aircraft design. Adaptive wing morphology in birds, including the Harris’ hawk, Common swift, Steppe eagle and Barn swallow, provides excellent examples of aerodynamic and flight control effectiveness that inform the Aeronautical Engineer. The Harris’ hawk and Common swift are gliding birds that change their wing and tail span according to gliding velocity. Inspired by the natural world, effective wing geometry is also modified in aircraft to adjust the aerodynamic load. Bird wings employ an automatic aeroelastic deflection of covert feathers that extend the range of flight configurations and maintain control authority in different flight regimes. Similarly, aircraft structures are not completely rigid and aeroelasticity is important in aircraft. In a Steppe eagle, the alula functions as a high-lift device analogous to the leading edge slats in aircraft wings that allow flight at high angles of attack and low airspeeds without stalling. It has also been suggested that the alula functions as a strake that triggers the development of a leading-edge vortex typical of aircraft delta wings. Sweep-back morphs the hand wing of birds into delta wings that produce lift-generating leading-edge-vortices.
    [Show full text]
  • Analysis of a High-Lift Device by Boundary Layer Blowing System
    University Degree in Aerospace Engineering Academic Year 2018-2019 Analysis of a high-lift device by boundary layer blowing system. Bachelor Thesis By Martín López Meijide Tutored and Supervised by Pablo Fajardo Peña July 2019 This work is licensed under Creative Commons Attribution – Non Commercial – Non Derivatives Martín López Meijide Bachelor Thesis Universidad Carlos III de Madrid 2 Martín López Meijide Bachelor Thesis Universidad Carlos III de Madrid Abstract Boundary layer control is a very important subject of investigation in fluid mechanics. The invention of high-lift devices in aircrafts has allowed to increase the capabilities of aerodynamic profiles. This thesis explores one opportunity of taking advantage of boundary layer control in turbulent regimes by means of a blowing system. Carefully CFD simulations have been performed with ANSYS Fluent at different angles of attack for the 2D NACA 4412 airfoil. The boundary conditions are sea level conditions for incompressible flow at Reynold number of 4.8 million, chord of 1m and Mach number of 0.2 for flow velocity. Three modifications of the airfoil geometry have been created at 61%, 50% and 39% of the chord. Each modification includes a slot for the blowing jet of height of 1% of the total chord. The results showed that the blowing system increases the lift coefficient and the aerodynamic efficiency at high angles of attack, which is very useful in take-off and landing configurations. The location of the blowing system at 50% of the chord showed to be the best location for the device. In conclusion, this high-lift device should be implemented and studied further in 3D cases, since it might be an innovative element not only in the aerospace industry, but also other fields of study like wind turbines or nautical ships.
    [Show full text]
  • Drag Reduction with Riblets in Nature and Engineering
    Drag reduction with riblets in nature and engineering D.W. Bechert & W. Hage Department of Turbulence Research, German Aerospace Center (DLR), Berlin, Germany. Abstract Reduction of wall friction of turbulent boundary layer flows can be achieved by using surfaces with properties that are related to skin structures occurring in nature. The scales of several species of fast-swimming sharks show a tiny ribbed structure. This ribbed structure hampers the momentum exchange at the surface that is the origin of the turbulent shear stress.The drag-reducing mechanism of ribbed surfaces (or riblets) is explained by using an analytical model that defines the viscous region of the flow, where the riblets are completely immersed in the viscous sublayer of the turbulent boundary layer. Wall shear stress reduction has been investigated experimentally for various riblet surfaces including a replica of sharkskin consisting of 800 plastic model scales with compliant anchoring. The application of these types of structure to long-range commercial aircraft is discussed, including the effect of the drag reductions on the operational costs of the aircraft. 1 Introduction Drag reduction of a moving animal or vehicle can be achieved by a reduction of wall shear stress and, in some situations, by separation control. Here we focus on turbulent wall shear stress reduction. Obviously laminar flow, which has been successfully used on glider wings, offers the lowest attainable wall shear stress. On commercial aircraft, however, the problems associated with the implementation of laminar flow on swept transonic wings are at present not yet completely solved. Even when laminar flow is maintained over a major percentage of the wing, most of the aircraft surface will still have a turbulent boundary layer.
    [Show full text]
  • Moving Surface Boundary Layer Control Analysis and the Influence of the Magnus Effect on an Aerofoil with a Leading-Edge Rotatin
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 14 May 2019 doi:10.20944/preprints201905.0170.v1 Article Moving surface boundary layer control analysis and the influence of the Magnus effect on an aerofoil with a leading-edge rotating cylinder Md. Abdus Salam1,*, Bhuiyan Shameem Mahmood Ebna Hai2,†, M. A. Taher Ali1, Debanan Bhadra1, and Nafiz Ahmed Khan1 1 Department of Aeronautical Engineering, Military Institute of Science and Technology, Dhaka, Bangladesh. 2 Faculty of Mechanical Engineering, Helmut Schmidt University, Hamburg, Germany. * Lead author; E-mail: [email protected]. † Corresponding author; E-mail: [email protected]. Received: date; Accepted: date; Published: date Abstract: A number of experimental and numerical studies point out that incorporating a rotating cylinder can superiorly enhance the aerofoil performance, especially for higher velocity ratios. Yet, there have been less or no studies exploring the effects of lower velocity ratio at a higher Reynolds number. In the present study, we investigated the effects of Moving Surface Boundary-layer Control (MSBC) at lower velocity ratios (i.e. cylinder tangential velocity to free stream velocity) and higher Reynolds number on a symmetric aerofoil (e.g. NACA 0021) and an asymmetric aerofoil (e.g. NACA 23018). In particular, the aerodynamic performance with and without rotating cylinder at the leading edge of the NACA 0021 and NACA 23018 aerofoil was studied on the wind tunnel installed at Aerodynamics Laboratory. The aerofoil section was tested in the low subsonic wind tunnel, and the lift coefficient (CL) and the drag coefficient (CD) were studied for different angles of attack (a).
    [Show full text]
  • A Review of the Magnus Effect in Aeronautics
    Progress in Aerospace Sciences 55 (2012) 17–45 Contents lists available at SciVerse ScienceDirect Progress in Aerospace Sciences journal homepage: www.elsevier.com/locate/paerosci A review of the Magnus effect in aeronautics Jost Seifert n EADS Cassidian Air Systems, Technology and Innovation Management, MEI, Rechliner Str., 85077 Manching, Germany article info abstract Available online 14 September 2012 The Magnus effect is well-known for its influence on the flight path of a spinning ball. Besides ball Keywords: games, the method of producing a lift force by spinning a body of revolution in cross-flow was not used Magnus effect in any kind of commercial application until the year 1924, when Anton Flettner invented and built the Rotating cylinder first rotor ship Buckau. This sailboat extracted its propulsive force from the airflow around two large Flettner-rotor rotating cylinders. It attracted attention wherever it was presented to the public and inspired scientists Rotor airplane and engineers to use a rotating cylinder as a lifting device for aircraft. This article reviews the Boundary layer control application of Magnus effect devices and concepts in aeronautics that have been investigated by various researchers and concludes with discussions on future challenges in their application. & 2012 Elsevier Ltd. All rights reserved. Contents 1. Introduction .......................................................................................................18 1.1. History .....................................................................................................18
    [Show full text]
  • Parametric Investigation of Boundary Layer Control Using Triangular Micro Vortex Generators
    EPJ Web of Conferences 67, 0 20 03 (2014) DOI: 10.1051/epjconf/20146702003 C Owned by the authors, published by EDP Sciences, 2014 Parametric investigation of boundary layer control using triangular micro vortex generators Milad Bagheri1,a, Motassem Al Muslmani1, Asad Masood1, Mahmood Khosravi1, Mohamed Atef Mahmoud1, Aniket Cardoz1, Abdulrahman Akkuwari1, Yusuf Alanezi1, and Young Kim2. 1Aerodynamics, Dept of Aeronautical Engineering, Emirates Aviation College, Dubai, UAE 2Assistant professor, Dept, of Aeronautical Engineering, P.O. Box 53044, Emirates Aviation College, Dubai, UAE Abstract. Improving the aerodynamic performance of an airfoil is one of the primary interests of the Aerodynamicists. Such performance improvement can be achieved using passive or active flow control devices. One of such passive devices having a compact size along with an effective performance is the Micro Vortex Generators (MVGs). A special type of MVGs, which has been recently introduced in the aerospace industry, is “Triangular Shape” MVGs and its impact on aerodynamic characteristics is the main interest of this study. This study will compare the effects of various configurations through which delay of the flow separation using boundary layer control will be analysed by experimental and theoretical approach. The experimental investigations have been conducted using subsonic wind tunnel and the theoretical analysis using ANSYS® 13.0 FLUENT of which the final results are compared with each other. 1 Introduction triangular MVGs and to identify the best triangular configuration with best aerodynamic performance. Engineers around the world are constantly refining, developing and experimenting new methods in improving 2 Motivation aircraft performance. One of such flight performance enhancing device is the Triangular MVGs.
    [Show full text]
  • Active Boundary Layer Control on a Highly Loaded Turbine Exit Case Profile
    Article Active Boundary Layer Control on a Highly Loaded Turbine Exit Case Profile† Julia Kurz 1,*, Martin Hoeger 2 and Reinhard Niehuis 1 ID 1 Institute of Jet Propulsion, Bundeswehr University Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg; Germany; [email protected] 2 MTU Aero Engines AG, Dachauer Str. 665, 80995 München, Germany; [email protected] * Correspondence: [email protected]; Tel.: +49-(0)89-6004-2873 † This paper is an extended version of our paper published in Proceedings of the European Turbomachinery Conference ETC12 2017, Paper No. 191. Received: 30 December 2017; Accepted: 26 February 2018; Published: 6 March 2018 Abstract: A highly loaded turbine exit guide vane with active boundary layer control was investigated experimentally in the High Speed Cascade Wind Tunnel at the University of the German Federal Armed Forces, Munich. The experiments include profile Mach number distributions, wake traverse measurements as well as boundary layer investigations with a flattened Pitot probe. Active boundary layer control by fluidic oscillators was applied to achieve improved performance in the low Reynolds number regime. Low solidity, which can be applied to reduce the number of blades, increases the risk of flow separation resulting in increased total pressure losses. Active boundary layer control is supposed to overcome these negative effects. The experiments show that active boundary layer control by fluidic oscillators is an appropriate way to suppress massive open separation bubbles in the low Reynolds number regime. Keywords: turbine exit case; active flow control; low Reynolds numbers 1. Introduction Full order books of aircraft manufacturers indicate a huge demand for new highly efficient aircraft, even in times of falling oil prices.
    [Show full text]
  • Blowing and Suction Flow Separation Control Over NACA 0012 Airfoil
    Journal of Mechanical Science and Technology 28 (4) (2014) 1297~1310 www.springerlink.com/content/1738-494x DOI 10.1007/s12206-014-0119-1 Numerical study of blowing and suction slot geometry optimization on NACA 0012 airfoil† Kianoosh Yousefi*, Reza Saleh and Peyman Zahedi Department of Mechanical Engineering, College of Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran (Manuscript Received March 1, 2013; Revised July 10, 2013; Accepted November 9, 2013) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Abstract The effects of jet width on blowing and suction flow control were evaluated for a NACA 0012 airfoil. RANS equations were em- ployed in conjunction with a Menter’s shear stress turbulent model. Tangential and perpendicular blowing at the trailing edge and per- pendicular suction at the leading edge were applied on the airfoil upper surface. The jet widths were varied from 1.5% to 4% of the chord length, and the jet velocity was 0.3 and 0.5 of the free-stream velocity. Results of this study demonstrated that when the blowing jet width increases, the lift-to-drag ratio rises continuously in tangential blowing and decreases quasi-linearly in perpendicular blowing. The jet widths of 3.5% and 4% of the chord length are the most effective amounts for tangential blowing, and smaller jet
    [Show full text]
  • Laminar How Control (1976- 1982)
    NASA T" 84496 NASATechnical Memomdm 844% c.1 Laminar How Control (1976-1982) A Selected, Annotated Bibliography Marie H. Tuttle and Dal V. Maddalon AUGUST 1982 " . .. - " NASA NASATechnical Memorandm -% Laminar flow Control (1976-1982) A Selected, Annotated Bibliography Marie H. Tuttle and Dal V. Maddalon Langley Research Center Hampton, Virginia National Aeronautics and Space Administration Scientlflc and Technlcal Information Branch \. i ” INTRODUCTION .................................................................... 1 BIBLIOGRAPHY (1976-1982) ........................................................ 3 APPENDIX ........................................................................ 65 ENTRIES WITH PUBLICATIONDATES PRIOR TO 1976 .................................... 66 AUTHOR INDEX .................................................................... 76 iii INTRODUCTION Laminar Flow Control (LFC) technologydevelopment has undergone tremendous progress in recent years as focused research efforts in materials, aerodynamics, systems,and structures have begun to pay off. A virtualexplosion in the number of research papers published on this subject has occurred since interest was first stimulated by the 1976 introduction of the NASA's Aircraft EnergyEfficiency Laminar Flow Control (ACEE/LFC) Program.Today, a wide variety of fundamentaland applied researchprograms exist, not only in controlled (active) boundary-layer flow, but alsoin natural (passive) laminar flow. Studies of airfoils whichcombine the two methods (hybrid) are now beginning.
    [Show full text]
  • An Aerodynamic Model for Vane-Type Vortex Generators. In
    Poole, D. , Bevan, R., Allen, C., & Rendall, T. (2016). An Aerodynamic Model for Vane-Type Vortex Generators. In 8th AIAA Flow Control Conference (AVIATION2016) [AIAA 2016-4085] American Institute of Aeronautics and Astronautics Inc. (AIAA). https://doi.org/10.2514/6.2016-4085 Peer reviewed version Link to published version (if available): 10.2514/6.2016-4085 Link to publication record in Explore Bristol Research PDF-document This is the author accepted manuscript (AAM). The final published version (version of record) is available online via AIAA at http://arc.aiaa.org/doi/10.2514/6.2016-4085. Please refer to any applicable terms of use of the publisher. University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ An Aerodynamic Model for Vane-Type Vortex Generators D.J. Poole ,∗ R.L.T. Bevan ,y C.B. Allen ,z T.C.S. Rendallx Department of Aerospace Engineering, University of Bristol, Bristol, BS8 1TR, U.K. A new, physics-based model is presented for flows around vortex generators. The model uses a modified lifting-line method with added physics to account for boundary layer flow. The lifting-line method is extended to also include a vortex lift component and these two components are used to calculate the strength of a vortex shed from an isolated vortex gen- erator. The circulation model is developed further to be used within a CFD framework in a source term approach.
    [Show full text]
  • Overview of Laminar Flow Control
    NASA/TP-1998-208705 Overview of Laminar Flow Control Ronald D. Joslin Langley Research Center, Hampton, Virginia National Aeronautics and Space Administration Langley Research Center Hampton, Virginia 23681-2199 October 1998 Acknowledgment.,; The author's only intent in generating this overview was to summarize the available literature from a historical prospective while making no judgement on the value of any contribution. This publication is dedicated to the many scientists, engineers, and managers who have devoted a portion of their careers toward developing technologies which would someday lead to aircraft with laminar flow. Special thanks to Anna Ruzecki and Dee Bullock for graphics services which led to the reproduced figures, Eloise Johnson for technical editing services, and Patricia Gottschali for typesetting services. Gratitude is expressed to the following companies and reviewers of this manuscript or a portion of this manuscript: Scott G. Anders, Dennis M. Bushnell, Michael C. Fischer, Jerry N. Hefner, Dal V. Maddalon, William L. Sellers III, Richard A. Thompson, and Michael J. Walsh, Langley Research Center; Paul Johnson and Jeff Crouch, The Boeing Company; E. Kevin Hertzler, Lockheed Martin Corporation; and Feng Jiang, McDonnell Douglas Corporation. The use of trademarks or names of manufacturers in this report is for accurate reporting and does not constitute an official endorsement, either expressed or implied, of such products or _nanufacturers by the National Aeronautics and Space Administration. Available from the following: NASA Center for AeroSpace Information (CASI) National Technical Information Service (NTIS) 7121 Standard Drive 5285 Port Royal Road Hanover, MD 21076-1320 Springfield, VA 22161-2171 (301) 621-0390 (703) 487-465O Contents Tables ...........................................................................
    [Show full text]
  • Slot Suction of the Turbulent Boundary Layer an Experimental Study
    Slot Suction of the Turbulent Boundary Layer An Experimental Study Tim van der Hoeven March 28, 2013 Faculty of Aerospace Engineering ⋅ Delft University of Technology Slot Suction of the Turbulent Boundary Layer An Experimental Study Master of Science Thesis For obtaining the degree of Master of Science in Aerospace Engineering at Delft University of Technology Tim van der Hoeven March 28, 2013 Faculty of Aerospace Engineering ⋅ Delft University of Technology Copyright © Tim van der Hoeven All rights reserved. Delft University Of Technology Department Of Aerodynamics The undersigned hereby certify that they have read and recommend to the Faculty of Aerospace Engineering for acceptance a thesis entitled \Slot Suction of the Turbulent Boundary Layer" by Tim van der Hoeven in partial fulfillment of the requirements for the degree of Master of Science. Dated: March 28, 2013 Head of department: Prof. Dr. Ir. F. Scarano Supervisor: Dr. Ir. L.L.M. Veldhuis Reader: Dr. Ir. B.W. van Oudheusden Reader: Ir. E. Terry Reader: Dr. Ir. D. Ragni Abstract This study examines the effects of slot suction on the mean characteristics of a two-dimensional turbulent boundary layer. Previous studies on this subject have mainly focused on low Reynolds number boundary layers (i.e. Reθ ≤ 2,000). Furthermore, numerical tools are often not able to accurately predict the effects of slot suction. To grasp the effects of slot suction at conditions more relevant to engineering problems, the present research focuses on a turbulent boundary layer with a Reynolds number of Reθ ≈ 10,000. An experimental investigation has been conducted in the W-tunnel facility at the Delft Univer- sity of Technology.
    [Show full text]