THE BRIDGE COLLAPSED IN NOVEMBER 1940 AFTER 4 MONTHS OF ITS OPENING TO TRAFFIC!
|
|
- Reginald Golden
- 6 years ago
- Views:
Transcription
1
2 OUTLINE TACOMA NARROWS BRIDGE FLOW REGIME PAST A CYLINDER VORTEX SHEDDING MODES OF VORTEX SHEDDING PARALLEL & OBLIQUE FLOW PAST A SPHERE AND A CUBE SUMMARY
3 TACOMA NARROWS BRIDGE, USA THE BRIDGE COLLAPSED IN NOVEMBER 1940 AFTER 4 MONTHS OF ITS OPENING TO TRAFFIC!
4 TACOMA NARROWS BRIDGE, USA The dramatic collapse was induced due to VORTEX SHEDDING AT A WIND SPEED OF 42MPH! This is how strong a flow regime past a bluff body can become.
5 OVERVIEW OF FLOW REGIME PAST A CYLINDER The transitions in the flow regimes is affected by the roughness, turbulence levels, cylinder aspect ratio, end conditions and blockage. Re = STABLE LAMINAR SHEDDING REGIME. Re= TRANSITION REGIME. Re= IRREGULAR REGIME.
6 Flow past a cylinder (a) The flow past a cylinder for a very low Reynolds number. The flow smoothly divides and reunites around the cylinder. (b) At a Reynolds number of about 4, the flow (boundary layer) separates in the downstream and the wake is formed by two symmetric eddies. The eddies remain steady and symmetrical but grow in size up to a Reynolds number of about 40. (c) At a Reynolds number around 47, the wake starts shedding vortices into the stream.
7 VORTEX SHEDDING At around Re=47 vortex shedding begin to take place. A Hopf bifurcation is breaks the symmetry between the two eddies and with a slight bifurcation the vortex detaches itself from the body. In its place a new vortex is formed. The airflow past the object creates alternating low-pressure vortices on the downwind side of the object. The object will tend to move toward the low-pressure zone.
8 VON KÁRMÁN VORTEX STREET Over a large Re range (47<Re<10 7 for circular cylinders), eddies are shed continuously from each side of the body, forming rows of vortices in its wake. A Von Kármán vortex street is a repeating pattern of swirling vortices caused by the unsteady separation of flow over bluff bodies. They are named after the engineer & fluid dynamicist, Theodore von Kármán.
9 VON KÁRMÁN VORTEX STREET A video showing a smoke visualization of the FORMATION OF VORTEX STREETS as wind flows past a cylindrical body.
10 FORMATION OF VORTEX STREETS Vortices are shed in to the downstream flow from alternate sides of the body ( with alternate senses of rotation ), giving the appearance of alternately opposite signed vortices. Karman investigated the phenomenon and concluded that a nonstaggered row of vortices is unstable, and a staggered row is stable only if the ratio of lateral distance between the vortices to their longitudinal distance is Because of the similarity of the wake with footprints in a street, the staggered row of vortices behind a blue body is called a Karman Vortex Street. The vortices move downstream at a speed smaller than the upstream velocity U.
11 VORTEX DISLOCATIONS: Origin of fluctuations Existence of vortex dislocations in wake transition. Primary vortices move out of phase. Irregularities dominates downstream. LARGE LOW FREQUENCY IRREGULARITIES: Cross sectional and plane view
12 STROUHAL NUMBER When considering a long circular cylinder, the frequency of vortex shedding is given by the empirical formula Strouhal number= fd/v where f = Vortex shedding frequency While an eddy on one side is shed, that on the other side forms, resulting in an unsteady flow near the cylinder. As vortices of opposite circulations are shed off alternately from the two sides, the circulation around the cylinder changes sign, resulting in a lateral force. If the frequency of vortex shedding is close to the natural frequency of some mode of vibration of the cylinder body, then an appreciable lateral vibration culminates. This may cause large fluctuating pressure forces leading to structural vibrations, acoustic noise, or resonance.
13 EFFECTS OF VORTEX SHEDDING When the frequency of vortex shedding matches the resonance frequency of the structure, the structure will begin to resonate and the structure's movement can become self-sustaining. Vortex shedding was one of the causes proposed for the failure of the Tacoma Narrows Bridge in 1940 A thrill ride "Vertigo" in Ohio suffered the vortex shedding during the winter of 2001, one of the three towers collapsed. Vortex shedding caused the collapse of three towers at Ferrybridge power station in 1968 during high winds.
14 Flow at higher Reynolds number At about Re = 500, multiple frequencies start showing up and the wake tends to become Chaotic. As the Reynolds number becomes higher, the boundary layer around the cylinder tends to become turbulent. The wake, shows fully turbulent characters. For larger Reynolds numbers, the boundary layer becomes turbulent. A turbulent boundary layer offers greater resistance to separation than a laminar boundary layer. As a consequence the separation point moves downstream and the separation angle is delayed to from the forward stagnation point
15 STROUHAL NUMBER vs. REYNOLDS NUMBER Discontinuity is observed in the Strouhal (S) vs. Reynolds no. (Re) relationship in the laminar shedding regime. Scatter of the order of 20% Disparity, though U, D, f can be measured to 1% accuracy. Many explanations have been given over the years. S-Re discontinuity is explained by a changeover from one mode of oblique shedding to another. S = fd/v Re=ρVD/μ
16 MODES OF VORTEX SHEDDING PARALLEL MODE OBLIQUE MODE
17 SQUIRE S TRANSFORMATION For a given wake profile and Reynolds number, and for a parallel flow, if f is the frequency & σ is temporal growth of the most unstable 2D wave, then for an oblique wave at an angle θ f(θ)= f cos θ & σ(θ)= σ cos θ
18 UNIVERSAL STROUHAL CURVE With parallel shedding, the Strouhal - Reynolds Number curve is completely continuous. Garry Brown suggested that cylinder wake frequencies follow the same trend as oblique waves. Williamson defined a universal Strouhal curve in which the experimental oblique shedding data [S θ ] closely collapses onto the parallel shedding curve [S o ] by the transformation : S o = S θ / cosθ
19 OBLIQUE MODE OF VORTEX SHEDDING Even for a cylinder that is hundreds of diameters in length, the angle of shedding depends on the particular boundary conditions at the span wise ends of the cylinder. Shedding assumes a cellular structure, with different frequencies co-existing at different span wise locations.
20 PARALLEL MODE OF VORTEX SHEDDING Promotion of oblique shedding to parallel vortex shedding: Very large aspect ratios ( L/D > 2000) Slight speeding up of the flow near the ends
21 Techniques to manipulate end boundaries USING EDGE OF END PLATE: angling inwards the leading edge of endplates. USING COAXIAL END CYLINDERS: Ending the span with larger coaxial cylinders
22 Techniques to manipulate end boundaries USING CONTROL CYLINDERS: locating large cylinders normal and upstream of the test cylinder. USING SUCTION TUBES FROM DOWNSTREAM: incident flow near the ends is speeded up by suction pipe.
23 Flow past spheres: MAGNUS EFFECT A Transverse aerodynamic force can be detected on a rotating body. Magnus force results from the asymmetric distortion of the boundary layer displacement thickness caused by the combined spinning and flow past the sphere. Boundary layer separation is delayed on the side of the spinning object that is moving in the same direction as the free stream flow, while the separation occurs prematurely on the side moving against the free stream flow. The wake then shifts toward the side moving against the free stream flow.
24 AERODYNAMICS OF CRICKET BALLS The key to making a cricket ball swing is to cause a pressure difference between the two sides of the ball. Swing is achieved by keeping one side of the ball polished and bowling while keeping the seam at particular angle. This turbulent boundary layer by virtue of its increased energy, separates relatively late compared to the boundary layer on the nonseam side.
25 FLOW PAST SPHERES Calculated streamlines colored by velocity at Re = 100. Flow is steady and axis symmetric and exhibits a large (~D) toroidal vortex in the near wake. By Re = 211 the axial symmetry of the flow past the sphere breaks down although the flow remains temporarily steady. This figure shows select streamlines at Re = 250.
26 By Re = 270, the flow field becomes unsteady but periodic. Streamlines colored by pressure are shown here for every quarter period at Re = 300. The unsteadiness results from the rapid growth of a portion of the wake vortex. The section of the vortex formed in the separating shear layer at t = T/2 quickly outgrows its equilibrium strength. As it increases in strength, it eventually cuts itself from the wake and sheds.
27 FLOW PAST A CUBE Unlike spherical cylinders and cube, the square cylinders have sharp corners. The formation of vortices depends on the edges and the corners. The simulation of an external flow around a square cylinder at Re=22,000
28
29 SUMMARY Vortex shedding, vortex dislocations and different vortex shedding regimes. Oblique shedding and influence of end boundary conditions. Variation of Strouhal number with Reynolds no. Vortex shedding around spheres and cubes.
30 THANK YOU FOR YOUR ATTENTION.
et al. [25], Noack et al. [26] for circular cylinder flows, Van Oudheusden [27] for square cylinder and Durgesh [28] for a flat plate model. The first two modes appear as phase-shifted versions of each
More informationExperimental Investigation Of Flow Past A Rough Surfaced Cylinder
(AET- 29th March 214) RESEARCH ARTICLE OPEN ACCESS Experimental Investigation Of Flow Past A Rough Surfaced Cylinder Monalisa Mallick 1, A. Kumar 2 1 (Department of Civil Engineering, National Institute
More informationThe effect of back spin on a table tennis ball moving in a viscous fluid.
How can planes fly? The phenomenon of lift can be produced in an ideal (non-viscous) fluid by the addition of a free vortex (circulation) around a cylinder in a rectilinear flow stream. This is known as
More informationComputation of Flow Behind Three Side-by-Side Cylinders of Unequal/Equal Spacing
Computation of Flow Behind Three Side-by-Side Cylinders of Unequal/Equal Spacing H. K. Virahsawmy 1, L. Chen 2, I. R. MacGillivray 2, J. Tu 1 and Y. Zhou 3 1. School of Aerospace, Mechanical and Manufacturing
More informationFlow Over Bodies: Drag and Lift
Fluid Mechanics (0905241) Flow Over Bodies: Drag and Lift Dr.-Eng. Zayed dal-hamamre 1 Content Overview Drag and Lift Flow Past Objects Boundary Layers Laminar Boundary Layers Transitional and Turbulent
More informationMethods The experiments were carried out in the wind tunnel in the Air physics laboratory at the Engineering Centre Bygholm as shown in figure 1.
1 Standardisation of test method for salt spreader: Air flow experiments Report 2: Visualization of airflow patterns by Jan S. Strøm, Consultant Aarhus University, Engineering Centre Bygholm, Test and
More informationEXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES
EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES Abdul Ahad Khan 1, Abhishek M. B 2, Tresa Harsha P George 3 1 Under Graduate student, Department of Aeronautical
More informationTHE TACOMA NARROWS BRIDGE FAILURE Revision A
By Tom Irvine Email: tomirvine@aol.com December 29, 1999 THE TACOMA NARROWS BRIDGE FAILURE Revision A Introduction The original Tacoma Narrows Bridge was opened to traffic on July 1, 1940. It was located
More informationBasic Fluid Mechanics
Basic Fluid Mechanics Chapter 7B: Forces on Submerged Bodies 7/26/2018 C7B: Forces on Submerged Bodies 1 Forces on Submerged Bodies Lift and Drag are forces exerted on an immersed body by the surrounding
More informationInfluence of rounding corners on unsteady flow and heat transfer around a square cylinder
Influence of rounding corners on unsteady flow and heat transfer around a square cylinder S. K. Singh Deptt. of Mech. Engg., M. B. M. Engg. College / J. N. V. University, Jodhpur, Rajasthan, India Abstract
More informationAE Dept., KFUPM. Dr. Abdullah M. Al-Garni. Fuel Economy. Emissions Maximum Speed Acceleration Directional Stability Stability.
Aerodynamics: Introduction Aerodynamics deals with the motion of objects in air. These objects can be airplanes, missiles or road vehicles. The Table below summarizes the aspects of vehicle performance
More informationTHREE DIMENSIONAL STRUCTURES OF FLOW BEHIND A
The Seventh Asia-Pacific Conference on Wind Engineering, November 8-12, 29, Taipei, Taiwan THREE DIMENSIONAL STRUCTURES OF FLOW BEHIND A SQUARE PRISM Hiromasa Kawai 1, Yasuo Okuda 2 and Masamiki Ohashi
More informationTHE CURVE OF THE CRICKET BALL SWING AND REVERSE SWING
Parabola Volume 32, Issue 2 (1996) THE CURVE OF THE CRICKET BALL SWING AND REVERSE SWING Frank Reid 1 It is a well known fact in cricket that the new ball when bowled by a fast bowler will often swing
More informationAsymmetric vortex shedding flow past an inclined flat plate at high incidence
Title Asymmetric vortex shedding flow past an inclined flat plate at high incidence Author(s) Lam, KM; Leung, MYH Citation European Journal Of Mechanics, B/Fluids, 5, v. 4 n., p. - 48 Issued Date 5 URL
More informationPrinciples of glider flight
Principles of glider flight [ Lecture 1: Lift, drag & glide performance ] Richard Lancaster Email: Richard@RJPLancaster.net Twitter: @RJPLancaster ASK-21 illustrations Copyright 1983 Alexander Schleicher
More informationThe Effect of Von Karman Vortex Street on Building Ventilation
The Effect of Von Karman Vortex Street on Building Ventilation P.Praveen Kumar Abstract This paper deals with the utilisation of the von Karman vortex street principle to maximise air flow into buildings.
More informationQuantification of the Effects of Turbulence in Wind on the Flutter Stability of Suspension Bridges
Quantification of the Effects of Turbulence in Wind on the Flutter Stability of Suspension Bridges T. Abbas 1 and G. Morgenthal 2 1 PhD candidate, Graduate College 1462, Department of Civil Engineering,
More informationEXPERIMENTAL STUDY OF WIND PRESSURES ON IRREGULAR- PLAN SHAPE BUILDINGS
BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 2-24 8 EXPERIMENTAL STUDY OF WIND PRESSURES ON IRREGULAR- PLAN SHAPE BUILDINGS J. A. Amin and A. K. Ahuja
More informationJournal of Engineering Science and Technology Review 6 (3) (2013) Research Article
Jestr Journal of Engineering Science and Technology Review 6 (3) (013) 105-110 Research Article JOURNAL OF Engineering Science and Technology Review www.jestr.org Lift and Drag on Cylinder of Octagonal
More informationNUMERICAL SIMULATION OF CROSS-FLOW AROUND FOUR CIRCULAR CYLINDERS IN-LINE SQUARE CONFIGURATION NEAR A PLANE WALL
NUMERICAL SIMULATION OF CROSS-FLOW AROUND FOUR CIRCULAR CYLINDERS IN-LINE SQUARE CONFIGURATION NEAR A PLANE WALL A. Grummy Wailanduw 1, Triyogi Yuwono 2 and Wawan Aries Widodo 2 1 Student of Doctoral Program
More informationDesign process to evaluate potential of wind noise at façade elements
Design process to evaluate potential of wind noise at façade elements Dr.Cristina Paduano 1, Dr.Jennifer Keenahan 1, Réamonn Mac Réamoinn 1 1 Arup, 50 Ringsend Road, Dublin 4, Ireland email: cristina.paduano@arup.com,
More informationExperimental investigation on the influence of wind direction on the aerodynamic loads acting on low aspect-ratio triangular prisms
Experimental investigation on the influence of wind direction on the aerodynamic loads acting on low aspect-ratio triangular prisms Giacomo Valerio Iungo and Guido Buresti Department of Aerospace Engineering,
More informationVORTEX SHEDDING AND VORTEX FORMATION FROM A PAIR OF IN-LINE FORCED OSCILLATING TANDEM ARRANGED CIRCULAR CYINDERS IN A UNIFORM FLOW
5 th International Symposium on Flow Visualization June 5-8,, Minsk, Belarus VORTEX SHEDDING AND VORTEX FORMATION FROM A PAIR OF IN-LINE FORCED OSCILLATING TANDEM ARRANGED CIRCULAR CYINDERS IN A UNIFORM
More informationAn Experimental Study of Vortex Shedding Behind a Bluff Body in a Water Channel
An Experimental Study of Vortex Shedding Behind a Bluff Body in a Water Channel ¹Meghanadhan C A, ² Sunil A S ¹PG Scholar, ² Associate Prof. Govt Engineering College Thrissur, Kerala,India Abstract-When
More informationAn Overview of Wind Engineering Where Climate Meets Design
An Overview of Wind Engineering Where Climate Meets Design Presented by Derek Kelly, M.Eng., P.Eng. Principal/Project Manager www.rwdi.com RWDI Leadership & Consulting Expertise RWDI Consulting Engineers
More informationEFFECT OF CORNER CUTOFFS ON FLOW CHARACTERISTICS AROUND A SQUARE CYLINDER
EFFECT OF CORNER CUTOFFS ON FLOW CHARACTERISTICS AROUND A SQUARE CYLINDER Yoichi Yamagishi 1, Shigeo Kimura 1, Makoto Oki 2 and Chisa Hatayama 3 ABSTRACT It is known that for a square cylinder subjected
More informationParasite Drag. by David F. Rogers Copyright c 2005 David F. Rogers. All rights reserved.
Parasite Drag by David F. Rogers http://www.nar-associates.com Copyright c 2005 David F. Rogers. All rights reserved. How many of you still have a Grimes rotating beacon on both the top and bottom of the
More informationJournal of Engineering Science and Technology Review 9 (5) (2016) Research Article. CFD Simulations of Flow Around Octagonal Shaped Structures
Jestr Journal of Engineering Science and Technology Review 9 (5) (2016) 72-76 Research Article JOURNAL OF Engineering Science and Technology Review www.jestr.org CFD Simulations of Flow Around Octagonal
More informationAERODYNAMICS I LECTURE 7 SELECTED TOPICS IN THE LOW-SPEED AERODYNAMICS
LECTURE 7 SELECTED TOPICS IN THE LOW-SPEED AERODYNAMICS The sources of a graphical material used in this lecture are: [UA] D. McLean, Understanding Aerodynamics. Arguing from the Real Physics. Wiley, 2013.
More informationCHAPTER-1 INTRODUCTION
CHAPTER-1 INTRODUCTION 1 1.1 Introduction This investigation documents the aerodynamic characteristics of four profiles, as cylinder, sphere, symmetrical aerofoil (NACA 0015) and cambered aerofoil (NACA
More informationHEFAT th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics July 2012 Malta
HEFAT212 9 th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics 16 18 July 212 Malta AN EXPERIMENTAL STUDY OF SWEEP ANGLE EFFECTS ON THE TRANSITION POINT ON A 2D WING BY USING
More informationNumerical Investigation of Flow Around Two Cylinders using Large-Eddy Simulation
Numerical Investigation of Flow Around Two Cylinders using Large-Eddy Simulation Baraal Qays Mahdi M. Sc. Student, Mechanical Engineering, Department of Mechanical Engineering. Universiti Kebangsaan Malaysia,
More informationCOMPUTATIONAL FLOW MODEL OF WESTFALL'S LEADING TAB FLOW CONDITIONER AGM-09-R-08 Rev. B. By Kimbal A. Hall, PE
COMPUTATIONAL FLOW MODEL OF WESTFALL'S LEADING TAB FLOW CONDITIONER AGM-09-R-08 Rev. B By Kimbal A. Hall, PE Submitted to: WESTFALL MANUFACTURING COMPANY September 2009 ALDEN RESEARCH LABORATORY, INC.
More information2013 Wall of Wind (WoW) Contest Informational Workshop
2013 Wall of Wind (WoW) Contest Informational Workshop Presented By: Ioannis Zisis February 22, 2013 With Contributions By: Dr. Girma Bitsuamlak, Roy Liu, Walter Conklin, Dr. Arindam Chowdhury, Jimmy Erwin,
More informationSEMI-SPAN TESTING IN WIND TUNNELS
25 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES SEMI-SPAN TESTING IN WIND TUNNELS S. Eder, K. Hufnagel, C. Tropea Chair of Fluid Mechanics and Aerodynamics, Darmstadt University of Technology
More informationFigure 1. Outer dimensions of the model trucks.
1 Standardisation of test method for salt spreader: Air flow experiments Report 3: Simulations of airflow patterns by Jan S. Strøm, Consultant Aarhus University, Engineering Centre Bygholm, Test and Development
More informationChapter 11 EXTERNAL FLOW: DRAG AND LIFT
Fluid Mechanics: Fundamentals and Applications, 2nd Edition Yunus A. Cengel, John M. Cimbala McGraw-Hill, 2010 Lecture slides by Mehmet Kanoglu Copyright The McGraw-Hill Companies, Inc. Permission required
More informationFLUID FORCE ACTING ON A CYLINDRICAL PIER STANDING IN A SCOUR
BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 20-24 2008 FLUID FORCE ACTING ON A CYLINDRICAL PIER STANDING IN A SCOUR Takayuki Tsutsui Department of
More informationAn experimental study of the parallel and oblique vortex shedding from circular cylinders
J. Fluid Mech. (1991), vol. 232, pp. 567-590 Printed in Great Britain 567 An experimental study of the parallel and oblique vortex shedding from circular cylinders By M. HAMMACHE AND M. GHARB Department
More informationAERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING
ICAS 2002 CONGRESS AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING Yoshiaki NAKAMURA (nakamura@nuae.nagoya-u.ac.jp) Takafumi YAMADA (yamada@nuae.nagoya-u.ac.jp) Department of Aerospace Engineering,
More informationA comparison of NACA 0012 and NACA 0021 self-noise at low Reynolds number
A comparison of NACA 12 and NACA 21 self-noise at low Reynolds number A. Laratro, M. Arjomandi, B. Cazzolato, R. Kelso Abstract The self-noise of NACA 12 and NACA 21 airfoils are recorded at a Reynolds
More informationWIND-INDUCED LOADS OVER DOUBLE CANTILEVER BRIDGES UNDER CONSTRUCTION
WIND-INDUCED LOADS OVER DOUBLE CANTILEVER BRIDGES UNDER CONSTRUCTION S. Pindado, J. Meseguer, J. M. Perales, A. Sanz-Andres and A. Martinez Key words: Wind loads, bridge construction, yawing moment. Abstract.
More informationLift for a Finite Wing. all real wings are finite in span (airfoils are considered as infinite in the span)
Lift for a Finite Wing all real wings are finite in span (airfoils are considered as infinite in the span) The lift coefficient differs from that of an airfoil because there are strong vortices produced
More informationAustralian Journal of Basic and Applied Sciences. Pressure Distribution of Fluid Flow through Triangular and Square Cylinders
AENSI Journals Australian Journal of Basic and Applied Sciences ISSN:1991-8178 Journal home page: www.ajbasweb.com Pressure Distribution of Fluid Flow through Triangular and Square Cylinders 1 Nasaruddin
More informationChapter 4: Single Vertical Arch
Chapter 4: Single Vertical Arch 4.1 Introduction This chapter considers a single pressurized arch in a vertical plane. This arch is similar to the arches that will be studied in the following chapter.
More informationExperimental investigation on the aerodynamic loads and wake flow features of low aspect-ratio triangular prisms at different wind directions
Journal of Fluids and Structures 25 (2009) 1119 1135 www.elsevier.com/locate/jfs Experimental investigation on the aerodynamic loads and wake flow features of low aspect-ratio triangular prisms at different
More informationInvestigation of Suction Process of Scroll Compressors
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 2006 Investigation of Suction Process of Scroll Compressors Michael M. Cui Trane Jack Sauls
More informationTwo staggered circular cylinders of equal diameter in cross-flow
Journal of Fluids and Structures 20 (2005) 255 276 www.elsevier.com/locate/jfs Two staggered circular cylinders of equal diameter in cross-flow D. Sumner, M.D. Richards, O.O. Akosile Department of Mechanical
More informationFigure 1 Figure 1 shows the involved forces that must be taken into consideration for rudder design. Among the most widely known profiles, the most su
THE RUDDER starting from the requirements supplied by the customer, the designer must obtain the rudder's characteristics that satisfy such requirements. Subsequently, from such characteristics he must
More informationEXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE
24 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE Lemes, Rodrigo Cristian,
More informationFLOW AND HEAT TRANSFER CHARACTERISTICS AROUND AN ELLIPTIC CYLINDER PLACED IN FRONT OF A CURVED PLATE
FLOW AND HEAT TRANSFER CHARACTERISTICS AROUND AN ELLIPTIC CYLINDER PLACED IN FRONT OF A CURVED PLATE Mahmoud S. Mostafa*, Radwan Kamal, and Mohamed Gobran Mechanical Power Dept., Faculty of engineering,
More informationNUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING EDGE AIRFOIL
BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 20-24 2008 NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING
More informationSPECIFYING MOTIONLESS MIXERS
SPECIFYING MOTIONLESS MIXERS The operating cost for the energy necessary to mix fluids with a motionless mixer is usually far lower than for any competitive mixing technique. An extruder which melts, mixes
More informationWind Flow Model of Area Surrounding the Case Western Reserve University Wind Turbine
Wind Flow Model of Area Surrounding the Case Western Reserve University Wind Turbine Matheus C. Fernandes 1, David H. Matthiesen PhD *2 1 Case Western Reserve University Dept. of Mechanical Engineering,
More informationPressure coefficient on flat roofs of rectangular buildings
Pressure coefficient on flat roofs of rectangular buildings T. Lipecki 1 1 Faculty of Civil Engineering and Architecture, Lublin University of Technology, Poland. t.lipecki@pollub.pl Abstract The paper
More informationKeywords: dynamic stall, free stream turbulence, pitching airfoil
Applied Mechanics and Materials Vol. 225 (2012) pp 103-108 Online available since 2012/Nov/29 at www.scientific.net (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/amm.225.103
More informationForces that govern a baseball s flight path
Forces that govern a baseball s flight path Andrew W. Nowicki Physics Department, The College of Wooster, Wooster, Ohio 44691 April 21, 1999 The three major forces that affect the baseball while in flight
More informationReduction of Skin Friction Drag in Wings by Employing Riblets
Reduction of Skin Friction Drag in Wings by Employing Riblets Kousik Kumaar. R 1 Assistant Professor Department of Aeronautical Engineering Nehru Institute of Engineering and Technology Coimbatore, India
More informationGeometry Modification For Minimizing The Aeroelastics Effect
Geometry Modification For Minimizing The Aeroelastics Effect Fariduzzaman a, Subagyo a, Fadilah Hasim a and Matza Gusto Andika a a Aero-Gas dynamics and Vibration Laboratory (LAGG), BPPT, PUSPIPTEK, Serpong
More informationEffects of seam and surface texture on tennis balls aerodynamics
Available online at www.sciencedirect.com Procedia Engineering 34 (2012 ) 140 145 9 th Conference of the International Sports Engineering Association (ISEA) Effects of seam and surface texture on tennis
More informationHomework #14, due Wednesday, Nov. 28 before class. Quiz #14, Wednesday November 28 at the beginning of class
ANNOUNCEMENTS Homework #14, due Wednesday, Nov. 28 before class Conceptual questions: Chapter 14, #8 and #16 Problems: Chapter 14, #58, #66 Study Chapter 14 by Wednesday Quiz #14, Wednesday November 28
More informationAN EXPERIMENTAL STUDY OF CRICKET BALL AERODYNAMICS
Proceedings of the International Conference on Mechanical Engineering 2007 (ICME2007) 29-31 December 2007, Dhaka, Bangladesh ICME07-FL-17 AN EXPERIMENTAL STUDY OF CRICKET BALL AERODYNAMICS Firoz Alam,
More informationEnergy from wind and water extracted by Horizontal Axis Turbine
Energy from wind and water extracted by Horizontal Axis Turbine Wind turbines in complex terrain (NREL) Instream MHK turbines in complex bathymetry (VP East channel NewYork) Common features? 1) horizontal
More informationAN EXPERIMENTAL STUDY OF THE EFFECTS OF SWEPT ANGLE ON THE BOUNDARY LAYER OF THE 2D WING
AN EXPERIMENTAL STUDY OF THE EFFECTS OF SWEPT ANGLE ON THE BOUNDARY LAYER OF THE 2D WING A. Davari *, M.R. Soltani, A.Tabrizian, M.Masdari * Assistant Professor, Department of mechanics and Aerospace Engineering,
More informationAF101 to AF109. Subsonic Wind Tunnel Models AERODYNAMICS. A selection of optional models for use with TecQuipment s Subsonic Wind Tunnel (AF100)
Page 1 of 4 A selection of optional models for use with TecQuipment s Subsonic Wind Tunnel (AF100) Dimpled Sphere Drag Model (from AF109) shown inside the TecQuipment AF100 Wind Tunnel. Cylinder, aerofoils,
More informationFlow Past A Cylinder With Upstream Splitter Plate
HEFAT2014 10 th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics 14 26 July 2014 Orlando, Florida Flow Past A Cylinder With Upstream Splitter Plate Rajkumar M.R* 1,Rijas A.S
More informationBioreactor System ERT 314. Sidang /2011
Bioreactor System ERT 314 Sidang 1 2010/2011 Chapter 2:Types of Bioreactors Week 4 Flow Patterns in Agitated Tanks The flow pattern in an agitated tank depends on the impeller design, the properties of
More informationWind Flow Validation Summary
IBHS Research Center Validation of Wind Capabilities The Insurance Institute for Business & Home Safety (IBHS) Research Center full-scale test facility provides opportunities to simulate natural wind conditions
More informationAvai 193 Fall 2016 Laboratory Greensheet
Avai 193 Fall 2016 Laboratory Greensheet Lab Report 1 Title: Instrumentation Test Technique Research Process: Break into groups of 4 people. These groups will be the same for all of the experiments performed
More informationPertanika J. Sci. & Technol. 24 (2): (2016) Flow Modification around a Circular Cylinder Applying Splitter Plates
Pertanika J. Sci. & Technol. 24 (2): 231-244 (2016) SCIENCE & TECHNOLOGY Journal homepage: http://www.pertanika.upm.edu.my/ Review Article Flow Modification around a Circular Cylinder Applying Splitter
More informationIncompressible Flow over Airfoils
Road map for Chap. 4 Incompressible Flow over Airfoils Aerodynamics 2015 fall - 1 - < 4.1 Introduction > Incompressible Flow over Airfoils Incompressible flow over airfoils Prandtl (20C 초 ) Airfoil (2D)
More informationDEFINITIONS. Aerofoil
Aerofoil DEFINITIONS An aerofoil is a device designed to produce more lift (or thrust) than drag when air flows over it. Angle of Attack This is the angle between the chord line of the aerofoil and the
More informationNUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT
- 277 - NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT Iseler J., Heiser W. EAS GmbH, Karlsruhe, Germany ABSTRACT A numerical study of the flow behaviour
More informationNAWEA 2015 SYMPOSIUM
Aerodynamics and Aeroacoustics of Spanwise Wavy Trailing Edge Flatback Airfoils: Design Improvement Seung Joon Yang James D. Baeder Alfred Gessow Rotorcraft Center Department of Aerospace Engineering,
More informationA Study on the Effects of Wind on the Drift Loss of a Cooling Tower
A Study on the Effects of Wind on the Drift Loss of a Cooling Tower Wanchai Asvapoositkul 1* 1 Department of Mechanical Engineering, Faculty of Engineering, King Mongkut s University of Technology Thonburi
More informationSurface obstacles in pulsatile flow
th International Symposium on Turbulence and Shear Flow Phenomena (TSFP), Chicago, USA, July, 2017 Surface obstacles in pulsatile flow Ian A. Carr, Michael W. Plesniak Department of Mechanical and Aerospace
More informationOPENINGS AND REINFORCEMENTS 26
ASME BPVC.VIII.1-2015 UG-35.2 UG-36 (4) It is recognized that it is impractical to write requirements to cover the multiplicity of devices used for quick access, or to prevent negligent operation or the
More informationAn experimental study on a suction flow control method to reduce the unsteadiness of the wind loads acting on a circular cylinder
Exp Fluids (24) 55:77 DOI.7/s348-4-77-7 RESEARCH ARTICLE An experimental study on a suction flow control method to reduce the unsteadiness of the wind loads acting on a circular cylinder Wen-Li Chen Hui
More informationExperimental Investigation of End Plate Effects on the Vertical Axis Wind Turbine Airfoil Blade
Experimental Investigation of End Plate Effects on the Vertical Axis Wind Turbine Airfoil Blade Rikhi Ramkissoon 1, Krishpersad Manohar 2 Ph.D. Candidate, Department of Mechanical and Manufacturing Engineering,
More informationUncontrolled copy not subject to amendment. Principles of Flight
Uncontrolled copy not subject to amendment Principles of Flight Principles of Flight Learning Outcome 1: Know the principles of lift, weight, thrust and drag and how a balance of forces affects an aeroplane
More informationDesigning a Model Rocket
Designing a Model Rocket Design Components In the following pages we are going to look at the design requirements for a stable single stage model rocket. From the diagram here you can see that the rocket
More informationWave Motion. interference destructive interferecne constructive interference in phase. out of phase standing wave antinodes resonant frequencies
Wave Motion Vocabulary mechanical waves pulse continuous periodic wave amplitude period wavelength period wave velocity phase transverse wave longitudinal wave intensity displacement amplitude phase velocity
More informationSubsonic wind tunnel models
aerodynamics AF1300a to AF1300l A selection of optional models for use with TecQuipment s Subsonic Wind Tunnel (AF1300) Dimpled Sphere Drag Model (from AF1300j) shown inside the TecQuipment AF1300 Wind
More informationThe Effect of Gurney Flap Height on Vortex Shedding Modes Behind Symmetric Airfoils
The Effect of Gurney Flap Height on Vortex Shedding Modes Behind Symmetric Airfoils Daniel R. Troolin 1, Ellen K. Longmire 2, Wing T. Lai 3 1: TSI Incorporated, St. Paul, USA, dan.troolin@tsi.com 2: University
More informationCitation Journal of Thermal Science, 18(4),
NAOSITE: Nagasaki University's Ac Title Author(s) Noise characteristics of centrifuga diffuser (Noise reduction by means leading tip) Murakami, Tengen; Ishida, Masahiro; Citation Journal of Thermal Science,
More informationGlobal aerodynamic instability of twin cylinders in cross flow
Global aerodynamic instability of twin cylinders in cross flow Md. Mahbub Alam 1,* and J.P. Meyer 2 1 Department of Mechanical and Automation Engineering Shenzhen Graduate School, Harbin Institute of Technology
More informationCHAPTER 8: MECHANICAL WAVES TRANSMIT ENERGY IN A VARIETY OF WAYS
CHAPTER 8: MECHANICAL WAVES TRANSMIT ENERGY IN A VARIETY OF WAYS DISCLAIMER FOR MOST QUESTIONS IN THIS CHAPTER Waves are always in motion, as they transmit energy and information from one point to another.
More informationHigh Swept-back Delta Wing Flow
Advanced Materials Research Submitted: 2014-06-25 ISSN: 1662-8985, Vol. 1016, pp 377-382 Accepted: 2014-06-25 doi:10.4028/www.scientific.net/amr.1016.377 Online: 2014-08-28 2014 Trans Tech Publications,
More informationNumerical simulation of two dimensional unsteady flow past two square cylinders
gopalax -International Journal of Technology And Engineering System(IJTES): Jan March 2011- Vol.2.No.3. Numerical simulation of two dimensional unsteady flow past two square cylinders Vikram C. K. 1, Dr.
More informationPerformance Improvements in Boeing/AFOSR Mach 6 Quiet Wind Tunnel Based on CFD Predictions
Performance Improvements in Boeing/AFOSR Mach 6 Quiet Wind Tunnel Based on CFD Predictions Hadassah Naiman, Doyle D. Knight Rutgers University Selin Aradag US Air Force Academy Thomas J. Juliano,, Steven
More informationFree Surface Flow Simulation with ACUSIM in the Water Industry
Free Surface Flow Simulation with ACUSIM in the Water Industry Tuan Ta Research Scientist, Innovation, Thames Water Kempton Water Treatment Works, Innovation, Feltham Hill Road, Hanworth, TW13 6XH, UK.
More informationUndertow - Zonation of Flow in Broken Wave Bores
Nearshore Circulation Undertow and Rip Cells Undertow - Zonation of Flow in Broken Wave Bores In the wave breaking process, the landward transfer of water, associated with bore and surface roller decay
More informationRESILIENT INFRASTRUCTURE June 1 4, 2016
RESILIENT INFRASTRUCTURE June 1 4, 2016 CASE STUDIES ON THE IMPACT OF SURROUNDING BUILDINGS ON WIND-INDUCED RESPONSE John Kilpatrick Rowan Williams Davies and Irwin, Guelph, Ontario, Canada ABSTRACT In
More informationUnsteady Wave-Driven Circulation Cells Relevant to Rip Currents and Coastal Engineering
Unsteady Wave-Driven Circulation Cells Relevant to Rip Currents and Coastal Engineering Andrew Kennedy Dept of Civil and Coastal Engineering 365 Weil Hall University of Florida Gainesville, FL 32611 phone:
More informationPERFORMANCE OF A FLAPPED DUCT EXHAUSTING INTO A COMPRESSIBLE EXTERNAL FLOW
24 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES PERFORMANCE OF A FLAPPED DUCT EXHAUSTING INTO A COMPRESSIBLE EXTERNAL FLOW P. R. Pratt, J. K. Watterson, E. Benard, S. Hall School of Aeronautical
More informationLecture # 08: Boundary Layer Flows and Drag
AerE 311L & AerE343L Lecture Notes Lecture # 8: Boundary Layer Flows and Drag Dr. Hui H Hu Department of Aerospace Engineering Iowa State University Ames, Iowa 511, U.S.A y AerE343L #4: Hot wire measurements
More informationDEPARTMENT OF THE NAVY NAVAL UNDERSEA WARFARE CENTER DIVISION NEWPORT
DEPARTMENT OF THE NAVY NAVAL UNDERSEA WARFARE CENTER DIVISION NEWPORT gsop P OFFICE OF COUNSEL (PATENTS) 14 1176 HOWELL STREET Q w BUILDING 112T, CODE OOOC NEWPORT, RHODE ISLAND 02841-1708 PHONE: 401 832-4736
More informationAerodynamic Terms. Angle of attack is the angle between the relative wind and the wing chord line. [Figure 2-2] Leading edge. Upper camber.
Chapters 2 and 3 of the Pilot s Handbook of Aeronautical Knowledge (FAA-H-8083-25) apply to powered parachutes and are a prerequisite to reading this book. This chapter will focus on the aerodynamic fundamentals
More information2.1 Introduction to pressure vessels
2.1 Introduction to pressure vessels Pressure vessels in the form of cylinders and tanks are used for storing variety of liquids and gasses at different temperatures and pressures. Some of the substances
More informationWIND ACTIONS AND RESPONSES OF STEEL CHIMNEYS
WIND ACTIONS AND RESPONSES OF STEEL CHIMNEYS I. STATIC WIND FORCES The force exerted by wind varies with the wind speed and its associated turbulence. Turbulence is affected by metrological factors, temperature
More information