The Physics of Sailing
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Airfoil Drag by Wake Survey Using Ldv
AIRFOIL DRAG BY WAKE SURVEY USING LDV 1 Purpose This experiment introduces the student to the use of Laser Doppler Velocimetry (LDV) as a means of measuring air flow velocities. The section drag of a NACA 0012 airfoil is determined from velocity measurements obtained in the airfoil wake. 2 Apparatus (1) .5 m x .7 m wind tunnel (max velocity 20 m/s) (2) NACA 0015 airfoil (0.2 m chord, 0.7 m span) (3) Betz manometer (4) Pitot tube (5) DISA LDV optics (6) Spectra Physics 124B 15 mW laser (632.8 nm) (7) DISA 55N20 LDV frequency tracker (8) TSI atomizer using 50cs silicone oil (9) XYZ LDV traversing system (10) Computer data reduction program 1 3 Notation A wing area (m2) b initial laser beam radius (m) bo minimum laser beam radius at lens focus (m) c airfoil chord length (m) Cd drag coefficient da elemental area in wake survey plane (m2) d drag force per unit span f focal length of primary lens (m) fo Doppler frequency (Hz) I detected signal amplitude (V) l distance across survey plane (m) r seed particle radius (m) s airfoil span (m) v seed particle velocity (instantaneous flow velocity) (m/s) U wake velocity (m/s) Uo upstream flow velocity (m/s) α Mie scatter size parameter/angle of attack (degs) δy fringe separation (m) θ intersection angle of laser beams λ laser wavelength (632.8 nm for He Ne laser) ρ air density at NTP (1.225 kg/m3) τ Doppler period (s) 4 Theory 4.1 Introduction The profile drag of a two-dimensional airfoil is the sum of the form drag due to boundary layer sep- aration (pressure drag), and the skin friction drag. -
Drag Force Calculation
DRAG FORCE CALCULATION “Drag is the component of force on a body acting parallel to the direction of relative motion.” [1] This can occur between two differing fluids or between a fluid and a solid. In this lab, the drag force will be explored between a fluid, air, and a solid shape. Drag force is a function of shape geometry, velocity of the moving fluid over a stationary shape, and the fluid properties density and viscosity. It can be calculated using the following equation, ퟏ 푭 = 흆푨푪 푽ퟐ 푫 ퟐ 푫 Equation 1: Drag force equation using total profile where ρ is density determined from Table A.9 or A.10 in your textbook A is the frontal area of the submerged object CD is the drag coefficient determined from Table 1 V is the free-stream velocity measured during the lab Table 1: Known drag coefficients for various shapes Body Status Shape CD Square Rod Sharp Corner 2.2 Circular Rod 0.3 Concave Face 1.2 Semicircular Rod Flat Face 1.7 The drag force of an object can also be calculated by applying the conservation of momentum equation for your stationary object. 휕 퐹⃗ = ∫ 푉⃗⃗ 휌푑∀ + ∫ 푉⃗⃗휌푉⃗⃗ ∙ 푑퐴⃗ 휕푡 퐶푉 퐶푆 Assuming steady flow, the equation reduces to 퐹⃗ = ∫ 푉⃗⃗휌푉⃗⃗ ∙ 푑퐴⃗ 퐶푆 The following frontal view of the duct is shown below. Integrating the velocity profile after the shape will allow calculation of drag force per unit span. Figure 1: Velocity profile after an inserted shape. Combining the previous equation with Figure 1, the following equation is obtained: 푊 퐷푓 = ∫ 휌푈푖(푈∞ − 푈푖)퐿푑푦 0 Simplifying the equation, you get: 20 퐷푓 = 휌퐿 ∑ 푈푖(푈∞ − 푈푖)훥푦 푖=1 Equation 2: Drag force equation using wake profile The pressure measurements can be converted into velocity using the Bernoulli’s equation as follows: 2Δ푃푖 푈푖 = √ 휌퐴푖푟 Be sure to remember that the manometers used are in W.C. -
Chapter 4: Immersed Body Flow [Pp
MECH 3492 Fluid Mechanics and Applications Univ. of Manitoba Fall Term, 2017 Chapter 4: Immersed Body Flow [pp. 445-459 (8e), or 374-386 (9e)] Dr. Bing-Chen Wang Dept. of Mechanical Engineering Univ. of Manitoba, Winnipeg, MB, R3T 5V6 When a viscous fluid flow passes a solid body (fully-immersed in the fluid), the body experiences a net force, F, which can be decomposed into two components: a drag force F , which is parallel to the flow direction, and • D a lift force F , which is perpendicular to the flow direction. • L The drag coefficient CD and lift coefficient CL are defined as follows: FD FL CD = 1 2 and CL = 1 2 , (112) 2 ρU A 2 ρU Ap respectively. Here, U is the free-stream velocity, A is the “wetted area” (total surface area in contact with fluid), and Ap is the “planform area” (maximum projected area of an object such as a wing). In the remainder of this section, we focus our attention on the drag forces. As discussed previously, there are two types of drag forces acting on a solid body immersed in a viscous flow: friction drag (also called “viscous drag”), due to the wall friction shear stress exerted on the • surface of a solid body; pressure drag (also called “form drag”), due to the difference in the pressure exerted on the front • and rear surfaces of a solid body. The friction drag and pressure drag on a finite immersed body are defined as FD,vis = τwdA and FD, pres = pdA , (113) ZA ZA Streamwise component respectively. -
Notes on Earth Atmospheric Entry for Mars Sample Return Missions
NASA/TP–2006-213486 Notes on Earth Atmospheric Entry for Mars Sample Return Missions Thomas Rivell Ames Research Center, Moffett Field, California September 2006 The NASA STI Program Office . in Profile Since its founding, NASA has been dedicated to the • CONFERENCE PUBLICATION. Collected advancement of aeronautics and space science. The papers from scientific and technical confer- NASA Scientific and Technical Information (STI) ences, symposia, seminars, or other meetings Program Office plays a key part in helping NASA sponsored or cosponsored by NASA. maintain this important role. • SPECIAL PUBLICATION. Scientific, technical, The NASA STI Program Office is operated by or historical information from NASA programs, Langley Research Center, the Lead Center for projects, and missions, often concerned with NASA’s scientific and technical information. The subjects having substantial public interest. NASA STI Program Office provides access to the NASA STI Database, the largest collection of • TECHNICAL TRANSLATION. English- aeronautical and space science STI in the world. language translations of foreign scientific and The Program Office is also NASA’s institutional technical material pertinent to NASA’s mission. mechanism for disseminating the results of its research and development activities. These results Specialized services that complement the STI are published by NASA in the NASA STI Report Program Office’s diverse offerings include creating Series, which includes the following report types: custom thesauri, building customized databases, organizing and publishing research results . even • TECHNICAL PUBLICATION. Reports of providing videos. completed research or a major significant phase of research that present the results of NASA For more information about the NASA STI programs and include extensive data or theoreti- Program Office, see the following: cal analysis. -
Equinox Manual
Racing Manual V1.2 January 2014 Contents Introduction ...................................................................................................................................... 3 The Boat ........................................................................................................................................ 3 Positions on a Sigma 38 ................................................................................................................. 4 Points of Sail .................................................................................................................................. 5 Tacking a boat ............................................................................................................................... 6 Gybing a boat ................................................................................................................................ 7 Essential knots all sailors should know ............................................................................................... 8 Bowline ......................................................................................................................................... 8 Cleat Knot ..................................................................................................................................... 8 Clove Hitch ................................................................................................................................... 8 Reef Knot...................................................................................................................................... -
USA Wins 33Rd America's Cup Match
Volume XXI No. 2 April/May 2010 USAUSA winswins 33rd33rd America’sAmerica’s CupCup MatchMatch BMW ORACLE Racing Team’s revolutionary wing sail powered trimaran USA Over 500 New and Used Boats Call for 2010 Dockage MARINA & SHIP’S STORE Downtown Bayfield Seasonal & Guest Dockage, Nautical Gifts, Clothing, Boating Supplies, Parts & Service 715-779-5661 apostleislandsmarina.net 2 Visit Northern Breezes Online @ www.sailingbreezes.com - April/May 2010 New New VELOCITEK On site INSTRUMENTS Sail repair IN STOCK AT Quick, quality DISCOUNT service PRICES Do it Seven Seas is now part of Shorewood Marina • Same location on Lake Minnetonka • Same great service, rigging, hardware, cordage, paint Lake Minnetonka’s • Inside boat hoist up to 27 feet—working on boats all winter Premier Sailboat Marina • New products—Blue Storm inflatable & Stohlquist PFD’s, Rob Line high-tech rope Now Reserving Slips for Spring Hours Mon & Wed Open House the 2010 Sailing Season! 9-7 Tues-Thur-Fri Saturday 8-5 April 10th Sat 9-3 Free food Closed Sundays Open House April 10th Are You Ready for Summer? 600 West Lake St., Excelsior, MN 55331 Just ½ mile north of Hwy 7 on Co. Rd. 19 952-474-0600 952-470-0099 [email protected] www.shorewoodyachtclub.com S A I L I N G S C H O O L Safe, fun, learning Learn to sail on Three Metro Lakes; Also Leech Lake, MN; Pewaukee Lake, WI; School of Lake Superior, Apostle Islands, Bayfield, WI; Lake Michigan; Caribbean Islands the Year On-the-water courses weekends, week days, evenings starting May: Gold Standard • Basic Small Boat -
Mylne Classic Regatta 2009 12Th—16Th July OFFICIAL PROGRAMME
£10 M 1896 Mylne Classic Regatta 2009 12th—16th July OFFICIAL PROGRAMME M 1896 1 8th June 2009 Thank you for your letter dated the 2nd June concerning the Mylne Classic Regatta which The Princess Royal has read with interest. As Patron of Royal Northern and Clyde Yacht Club, Her Royal Highness sends all concerned with the Mylne Classic Regatta in July her best wishes for a successful event. The Princess was particularly interested to read about George Lennox Watson’s work with the design of Britannia and that Alfred Mylne kept the rigging up to date. Her Royal Highness fully supports your work in reviving the interest in Alfred Mylne and sends all concerned with the Classic Regatta her best wishes. Captain Nick Wright, LVO, Royal Navy Private Secretary to HRH The Princess Royal Ms. Margaret Lobley M 1896 2 Contents Introduction ............................................................ 5 Event Information ............................................. 6 - 7 Regatta Course & Destination Details.............. 8 - 9 The Mylne Dynasty .........................................10 - 11 The Regatta Fleet ........................................... 12 - 22 Messages of Support ...................................... 23 - 25 Mylne Yachts Around The World ................. 26 - 27 The Chicane Restoration ...............................30 - 31 Lady Trix - The First 100 Years ............................. 32 Acknowledgements ............................................... 40 The Mylne Design List ....................................41 - 49 M 1896 3 Introduction am delighted to welcome you to the Mylne Classic Regatta 2009, celebrating the I world renowned yacht design heritage of A.Mylne & Co and its founder Alfred Mylne. This event is the first time owners of Mylne yachts (and selected guests) have gathered together under the Mylne flag. There are five days of celebrations based around Rhu and Rothesay to give owners, crews and enthusiasts lots of opportunity to mingle and admire the assembled yachts. -
Sail Trimming Guide for the Beneteau 37 September 2008
INTERNATIONAL DESIGN AND TECHNICAL OFFICE Sail Trimming Guide for the Beneteau 37 September 2008 © Neil Pryde Sails International 1681 Barnum Avenue Stratford, CONN 06614 Phone: 203-375-2626 • Fax: 203-375-2627 Email: [email protected] Web: www.neilprydesails.com All material herein Copyright 2007-2008 Neil Pryde Sails International All Rights Reserved HEADSAIL OVERVIEW: The Beneteau 37 built in the USA and supplied with Neil Pryde Sails is equipped with a 105% non-overlapping headsail that is 337sf / 31.3m2 in area and is fitted to a Profurl C320 furling unit. The following features are built into this headsail: • The genoa sheets in front of the spreaders and shrouds for optimal sheeting angle and upwind performance • The size is optimized to sheet correctly to the factory track when fully deployed and when reefed. • Reef ‘buffer’ patches are fitted at both head and tack, which are designed to distribute the loads on the sail when reefed. • Reefing marks located on the starboard side of the tack buffer patch provide a visual mark for setting up pre-determined reefing locations. These are located 508mm/1’-8” and 1040mm / 3’-5” aft of the tack. • A telltale ‘window’ at the leading edge of the sail located about 14% of the luff length above the tack of the sail and is designed to allow the helmsperson to easily see the wind flowing around the leading edge of the sail when sailing upwind and close-hauled. The tell-tales are red and green, so that one can quickly identify the leeward and weather telltales. -
Introduction to Aerodynamics < 1.7. Dimensional Analysis > Physical
Introduction to Aerodynamics < 1.7. Dimensional analysis > Physical parameters Q: What physical quantities influence forces and moments? V A l Aerodynamics 2015 fall - 1 - Introduction to Aerodynamics < 1.7. Dimensional analysis > Physical parameters Physical quantities to be considered Parameter Symbol units Lift L' MLT-2 Angle of attack α - -1 Freestream velocity V∞ LT -3 Freestream density ρ∞ ML -1 -1 Freestream viscosity μ∞ ML T -1 Freestream speed of sound a∞ LT Size of body (e.g. chord) c L Generally, resultant aerodynamic force: R = f(ρ∞, V∞, c, μ∞, a∞) (1) Aerodynamics 2015 fall - 2 - Introduction to Aerodynamics < 1.7. Dimensional analysis > The Buckingham PI Theorem The relation with N physical variables f1 ( p1 , p2 , p3 , … , pN ) = 0 can be expressed as f 2( P1 , P2 , ... , PN-K ) = 0 where K is the No. of fundamental dimensions Then P1 =f3 ( p1 , p2 , … , pK , pK+1 ) P2 =f4 ( p1 , p2 , … , pK , pK+2 ) …. PN-K =f ( p1 , p2 , … , pK , pN ) Aerodynamics 2015 fall - 3 - < 1.7. Dimensional analysis > The Buckingham PI Theorem Example) Aerodynamics 2015 fall - 4 - < 1.7. Dimensional analysis > The Buckingham PI Theorem Example) Aerodynamics 2015 fall - 5 - < 1.7. Dimensional analysis > The Buckingham PI Theorem Aerodynamics 2015 fall - 6 - < 1.7. Dimensional analysis > The Buckingham PI Theorem Through similar procedure Aerodynamics 2015 fall - 7 - Introduction to Aerodynamics < 1.7. Dimensional analysis > Dimensionless form Aerodynamics 2015 fall - 8 - Introduction to Aerodynamics < 1.8. Flow similarity > Dynamic similarity Two different flows are dynamically similar if • Streamline patterns are similar • Velocity, pressure, temperature distributions are same • Force coefficients are same Criteria • Geometrically similar • Similarity parameters (Re, M) are same Aerodynamics 2015 fall - 9 - Introduction to Aerodynamics < 1.8. -
Aerodynamic Force Measurement on an Icing Airfoil
AerE 344: Undergraduate Aerodynamics and Propulsion Laboratory Lab Instructions Lab #13: Aerodynamic Force Measurement on an Icing Airfoil Instructor: Dr. Hui Hu Department of Aerospace Engineering Iowa State University Office: Room 2251, Howe Hall Tel:515-294-0094 Email:[email protected] Lab #13: Aerodynamic Force Measurement on an Icing Airfoil Objective: The objective of this lab is to measure the aerodynamic forces acting on an airfoil in a wind tunnel using a direct force balance. The forces will be measured on an airfoil before and after the accretion of ice to illustrate the effect of icing on the performance of aerodynamic bodies. The experiment components: The experiments will be performed in the ISU-UTAS Icing Research Tunnel, a closed-circuit refrigerated wind tunnel located in the Aerospace Engineering Department of Iowa State University. The tunnel has a test section with a 16 in 16 in cross section and all the walls of the test section optically transparent. The wind tunnel has a contraction section upstream the test section with a spray system that produces water droplets with the 10–100 um mean droplet diameters and water mass concentrations of 0–10 g/m3. The tunnel is refrigerated by a Vilter 340 system capable of achieving operating air temperatures below -20 C. The freestream velocity of the tunnel can set up to ~50 m/s. Figure 1 shows the calibration information for the tunnel, relating the freestream velocity to the motor frequency setting. Figure 1. Wind tunnel airspeed versus motor frequency setting. The airfoil model for the lab is a finite wing NACA 0012 with a chord length of 6 inches and a span of 14.5 inches. -
1 Yacht Inhalt 2009
1 Ya ch t I n h alt 2 0 0 9 Aktion Dalton, Grant: Teilnahme am Volvo Ocean Race 10 11 Fotowettbewerb: Kuriose Aufnahmen 10 42-46 Darßer Ort: Hafenbau zurückgedreht, kein neuer Hafen in Prerow 19 8 Fotowettbewerb: Leserfoto des Jahres gesucht 10 52-53 Darßer Ort: Hafenneubau vor dem Aus? 10 12 Fotowettbewerb: Leserfoto des Jahres, die Sieger 22 36-44 De Rothschild, David: Expedition mit Recycling-Kat „Plastiki“ 7 14 Decksbelag: Bald kein Burma-Teak mehr zu haben 23 12 Aktuell Dekker, Laura: 14-Jährige auf Rekordfahrt nach Urteilsverkündung 18 14 Aktion: YACHT-Benefiz-Kunstauktion, Gemälde von F. Klatt 25 8 Dekker, Laura: Start zur Weltumsegelung von Gibraltar aus 20 10 Alkohol: Obergrenze 0,5 Promille 16 12 Design: Kombination Speedboot u. Yacht, Barcelona Yacht Design Group 9 8 Alkoholmissbrauch: 0 % in Bayern 12 8 DGzRS: Broschüre „Sicher auf See“ 15 14 Amel 64: Neue Ketsch aus Frankreich 2 12 DGzRS: Ehrung für Seenotretter Johann Niemann 17 9 America’s Cup: Gericht bestätigt Austragungsort Valencia 2 10 Di Benedetto, A.: Einhand-nonstop-Weltumsegelung mit 6,50-Yacht 17 9 America’s Cup: Kosten des Cups 6 8 Dom. Republik: Charterangebot von Barone Yachting 15 14 America’s Cup: L. Ellison mit Team auf Siegestour 7 14 Eissing, Thomas: Nachruf, Ingenieur verstorben 5 10 Antrieb: Manövrierhilfe „Dock and Go“ bei Bénéteau 19 12 Elbe: Mehr Service für Segler an der Unterelbe 22 9 ARC: Regatta erstmals live im Internet 1 10 Elektronik: Bodensee-Navigations-Programm für I-Phone 16 13 Aufgefischt: Als Bootsbauer vom Milliardär zum Millionär 5 10 -
SAFETY PRACTICES a BASIC GUIDE Adopted January 2002 Amended October 2014
INTERSCHOLASTIC SAILING ASSOCIATION SAFETY PRACTICES A BASIC GUIDE Adopted January 2002 Amended October 2014 Special thanks to our sister organization, the Intercollegiate Sailing Association of North America, for allowing us to use this Safety Guide, modeled after their own. TABLE OF CONTENTS General Safety Practices ..................................................... 1 Personal Equipment ............................................................ 2 Personal Training ................................................................ 4 Capsizes ............................................................................... 4 Safety Boats ........................................................................ 5 Safety Boat Crew Training ................................................... 6 Head Injury Awareness ....................................................... 9 References .......................................................................... 9 Foreword: Interscholastic (high school) sailing requires competitors to be safety conscious. It is our obligation to maintain the positive safety record that Interscholastic Sailing Association has enjoyed over the past 85 years. This is a BASIC GUIDE for Member Schools and District Associations to follow in regard to SAFETY PRACTICES during regattas, and instructional and recreational sailing. George H. Griswold As amended by Bill Campbell for ISSA 1. GENERAL SAFETY PRACTICES You sail because you enjoy it. In order to enhance and guarantee your enjoyment, there are a number of general