Chapter 12 Design of Control Surfaces
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Aerodynamics of High-Performance Wing Sails
Aerodynamics of High-Performance Wing Sails J. otto Scherer^ Some of tfie primary requirements for tiie design of wing sails are discussed. In particular, ttie requirements for maximizing thrust when sailing to windward and tacking downwind are presented. The results of water channel tests on six sail section shapes are also presented. These test results Include the data for the double-slotted flapped wing sail designed by David Hubbard for A. F. Dl Mauro's lYRU "C" class catamaran Patient Lady II. Introduction The propulsion system is probably the single most neglect ed area of yacht design. The conventional triangular "soft" sails, while simple, practical, and traditional, are a long way from being aerodynamically desirable. The aerodynamic driving force of the sails is, of course, just as large and just as important as the hydrodynamic resistance of the hull. Yet, designers will go to great lengths to fair hull lines and tank test hull shapes, while simply drawing a triangle on the plans to define the sails. There is no question in my mind that the application of the wealth of available airfoil technology will yield enormous gains in yacht performance when applied to sail design. Re cent years have seen the application of some of this technolo gy in the form of wing sails on the lYRU "C" class catamar ans. In this paper, I will review some of the aerodynamic re quirements of yacht sails which have led to the development of the wing sails. For purposes of discussion, we can divide sail require ments into three points of sailing: • Upwind and close reaching. -
Formula 1 Race Car Performance Improvement by Optimization of the Aerodynamic Relationship Between the Front and Rear Wings
The Pennsylvania State University The Graduate School College of Engineering FORMULA 1 RACE CAR PERFORMANCE IMPROVEMENT BY OPTIMIZATION OF THE AERODYNAMIC RELATIONSHIP BETWEEN THE FRONT AND REAR WINGS A Thesis in Aerospace Engineering by Unmukt Rajeev Bhatnagar © 2014 Unmukt Rajeev Bhatnagar Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science December 2014 The thesis of Unmukt R. Bhatnagar was reviewed and approved* by the following: Mark D. Maughmer Professor of Aerospace Engineering Thesis Adviser Sven Schmitz Assistant Professor of Aerospace Engineering George A. Lesieutre Professor of Aerospace Engineering Head of the Department of Aerospace Engineering *Signatures are on file in the Graduate School ii Abstract The sport of Formula 1 (F1) has been a proving ground for race fanatics and engineers for more than half a century. With every driver wanting to go faster and beat the previous best time, research and innovation in engineering of the car is really essential. Although higher speeds are the main criterion for determining the Formula 1 car’s aerodynamic setup, post the San Marino Grand Prix of 1994, the engineering research and development has also targeted for driver’s safety. The governing body of Formula 1, i.e. Fédération Internationale de l'Automobile (FIA) has made significant rule changes since this time, primarily targeting car safety and speed. Aerodynamic performance of a F1 car is currently one of the vital aspects of performance gain, as marginal gains are obtained due to engine and mechanical changes to the car. Thus, it has become the key to success in this sport, resulting in teams spending millions of dollars on research and development in this sector each year. -
Naca Research Memorandum
https://ntrs.nasa.gov/search.jsp?R=19930086840 2020-06-17T13:35:35+00:00Z Copy RMA5lll2 NACA RESEARCH MEMORANDUM A FLIGHT EVALUATION OF THE LONGITUDINAL STABILITY CHARACTERISTICS ASSOCIATED WITH THE PITCH-TIP OF A SWEPT-WING AIRPLANE IN MANEUVERING FLIGHT AT TRANSONIC SPEEDS 4'YJ A By Seth B. Anderson and Richard S. Bray Ames Aeronautical Laboratory Moffett Field, Calif. ENGINEERING DPT, CHANCE-VOUGHT AIRuRAf' DALLAS, TEXAS This material contains information hi etenoe toe jeoted States w:thin toe of the espionage laws, Title 18, 15 and ?j4, the transnJssionc e reveLation tnotct: in manner to unauthorized person Is et 05 Lan. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS WASHINGTON November 27, 1951 NACA RM A51112 INN-1.W, NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS A FLIGHT EVALUATION OF THE LONGITUDINAL STABILITY CHARACTERISTICS ASSOCIATED WITH THE PITCH-UP OF A SWEPT-WING AIPLAI'1E IN MANEUVERING FLIGHT AT TRANSONIC SPEEDS By Seth B. Anderson and Richard S. Bray SUMMARY Flight measurements of the longitudinal stability and control characteristics were made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. The results showed that the pitch-up. encountered in a wind-up turn at constant Mach number was caused principally by an unstable break in the wing pitching moment with increasing lift. This unstable break in pitching moment, which was associated with flow separation near the wing tips, was not present beyond approximately 0.93 Mach number over the lift range covered in these tests. The pitch-up encountered in a high Mach number dive-recovery maneuver was due chiefly to a reduction in the wing- fuselage stability with decreasing Mach number. -
Upwind Sail Aerodynamics : a RANS Numerical Investigation Validated with Wind Tunnel Pressure Measurements I.M Viola, Patrick Bot, M
Upwind sail aerodynamics : A RANS numerical investigation validated with wind tunnel pressure measurements I.M Viola, Patrick Bot, M. Riotte To cite this version: I.M Viola, Patrick Bot, M. Riotte. Upwind sail aerodynamics : A RANS numerical investigation validated with wind tunnel pressure measurements. International Journal of Heat and Fluid Flow, Elsevier, 2012, 39, pp.90-101. 10.1016/j.ijheatfluidflow.2012.10.004. hal-01071323 HAL Id: hal-01071323 https://hal.archives-ouvertes.fr/hal-01071323 Submitted on 8 Oct 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. I.M. Viola, P. Bot, M. Riotte Upwind Sail Aerodynamics: a RANS numerical investigation validated with wind tunnel pressure measurements International Journal of Heat and Fluid Flow 39 (2013) 90–101 http://dx.doi.org/10.1016/j.ijheatfluidflow.2012.10.004 Keywords: sail aerodynamics, CFD, RANS, yacht, laminar separation bubble, viscous drag. Abstract The aerodynamics of a sailing yacht with different sail trims are presented, derived from simulations performed using Computational Fluid Dynamics. A Reynolds-averaged Navier- Stokes approach was used to model sixteen sail trims first tested in a wind tunnel, where the pressure distributions on the sails were measured. -
Technical Memorandum X-26
.. .. 1 NASA TM X-26 TECHNICAL MEMORANDUM X-26 DESIGN GUIDE FOR PITCH-UP EVALUATION AND INVESTIGATION AT HIGH SUBSONIC SPEEDS OF POSSIBLE LlMITATIONS DUE TO WING-ASPECT-RATIO VARIATIONS By Kenneth P. Spreemann Langley Research Center Langley Field, Va. Declassified July 11, 1961 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON August 1959 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION . TEKX"NCAL MEMORANDUM x-26 DESIGN GUIDE FOR PITCH-UP EVALUATION AND INVESTIGATION AT HIGH SUBSONIC SPEEDS OF POSSIBLE LIMITATIONS DUE TO WING-ASPECT-RATIO VARIATIONS J By Kenneth P. Spreemann SUMMARY A design guide is suggested as a basis for indicating combinations of airplane design variables for which the possibilities of pitch-up are minimized for tail-behind-wing and tailless airplane configurations. The guide specifies wing plan forms that would be expected to show increased tail-off stability with increasing lift and plan forms that show decreased tail-off stability with increasing lift. Boundaries indicating tail-behind-wing positions that should be considered along with given tail-off characteristics also are suggested. An investigation of one possible limitation of the guide with respect to the effects of wing-aspect-ratio variations on the contribu- tion to stability of a high tail has been made in the Langley high-speed 7- by 10-foot tunnel through a Mach number range from 0.60 to 0.92. The measured pitching-moment characteristics were found to be consistent with those of the design guide through the lift range for aspect ratios from 3.0 to 2.0. However, a configuration with an aspect ratio of 1.55 failed to provide the predicted pitch-up warning characterized by sharply increasing stability at the high lifts following the initial stall before pitching up. -
Hero Or the Zero1
“Hero or the Zero” Chapter 1 A True Story By COL GREGORY MARSTON (ret) Aviation is an exciting profession that has short, intense, high-energy periods that are often followed by fairly routine and even boring phases of flight. Yet, it is important to remember always that you’re flying a machine at relatively high speeds and/or high altitudes versus other man-made equipment like a car. Your happy little pilot bubble can be interrupted in a Nano- second by the rare, heart-stopping, bowel-loosening, emergency that must be dealt with correctly, quickly and coolly or you may die. Sometimes you die, even if you do everything right! This story is about one such moment. I was leading a routine flight of two A-37B “Dragonfly” aircraft on a cool, clear and very dark, early morning at Davis-Monthan Air Force Base (DMAFB) in Tucson, Arizona on January 3rd, 1985. The A-37 was a relic from the Vietnam War, a small, green/grey camouflage, two-seat, two-engine, jet aircraft that was used for Attack (dropping bombs) or Forward Air Control (FAC – shooting rockets). As the solo Instructor Pilot (flying in the left seat) the plan was for me to takeoff first, followed 10 seconds later by my wingman (a student in the left seat and his Instructor Pilot in the right side). After takeoff, my wingman he would rejoin on me for a Close Air Support (CAS) training flight. I would lead the two-aircraft flight out to one of the massive bombing ranges located in southern Arizona. -
09 Stability and Control
Aircraft Design Lecture 9: Stability and Control G. Dimitriadis Introduction to Aircraft Design Stability and Control H Aircraft stability deals with the ability to keep an aircraft in the air in the chosen flight attitude. H Aircraft control deals with the ability to change the flight direction and attitude of an aircraft. H Both these issues must be investigated during the preliminary design process. Introduction to Aircraft Design Design criteria? H Stability and control are not design criteria H In other words, civil aircraft are not designed specifically for stability and control H They are designed for performance. H Once a preliminary design that meets the performance criteria is created, then its stability is assessed and its control is designed. Introduction to Aircraft Design Flight Mechanics H Stability and control are collectively referred to as flight mechanics H The study of the mechanics and dynamics of flight is the means by which : – We can design an airplane to accomplish efficiently a specific task – We can make the task of the pilot easier by ensuring good handling qualities – We can avoid unwanted or unexpected phenomena that can be encountered in flight Introduction to Aircraft Design Aircraft description Flight Control Pilot System Airplane Response Task The pilot has direct control only of the Flight Control System. However, he can tailor his inputs to the FCS by observing the airplane’s response while always keeping an eye on the task at hand. Introduction to Aircraft Design Control Surfaces H Aircraft control -
Bicycle Landing Gear Is Useful for High-Wing Airplanes with Long Span
Aeronautical Engineering Design I Landing Gear Sizing and Placement Prof. Dr. Serkan Özgen Dept. Aerospace Engineering December 2017 Landing gear configurations 2 Tricycle landing gear 3 Tricycle landing gear • Advantages of tricycle landing gear: ⁻ Cabin floor is horizontal when the airplane is on the ground. ⁻ Forward visibility is improved for the pilot when the airplane is on the gound. ⁻ The CG is ahead of the main wheels and this enhances stability during the ground roll. 4 Tricycle landing gear 5 Tricycle landing gear • The length of the landing gear must be set so that the tail doesn’t hit the ground during landing. • This is measured from the wheel in the static position assuming an angle of attack for landing that gives 90% of maximum lift, usually 10o-15o. • The tipback angle is the maximum aircraft nose-up attitude when the tail is touching the ground and the landing gear strut is fully extended. • To prevent the aircraft from tipping back on its tail, the angle of the vertical from the main wheel position to the cg should be greater than the tipback angle or 15o, whichever is greater. 6 Tricycle landing gear • Tipback angle should not be greater than 25o, otherwise porpoising will occur and a high elevator deflection will be required for rotation during takeoff. • This means that more than 20% of aircraft weight is carried by the nose wheel. • The optimum range for the percentage of aircraft weight that is carried by the nose wheel is 8-15% for the most aft and most forward CG positions. -
DESIGN and ANALYSIS of PERFORMANCE PARAMETERS of WING with FLAPERONS Debanjali Dey, R.Aasha #Department of Aeronautical Engineering , KCG College of Technology
International Journal of Scientific Research and Review ISSN NO: 2279-543X DESIGN AND ANALYSIS OF PERFORMANCE PARAMETERS OF WING WITH FLAPERONS Debanjali Dey, R.Aasha #Department of Aeronautical Engineering , KCG College Of Technology. 1. [email protected] 2. [email protected] ABSTRACT- The main objective of this project is to design a flaperon for a wing and compare the performance characteristic of this flaperon-wing combination with that of conventional wing design that makes use of separate flap and aileron. Theoretical analysis and comparison is performed following which the computational analysis is carried out to validate the results. Further aim is to give a clarity on the fact that the use of this high lift device aids in improvising the aerodynamic characteristics of a wing by experimental testing of the wing design incorporated with flaperon, which is designed using a special methodology. Then, modification of wing design can be done to overcome the drawbacks of flaperons if any. INTRODUCTION - When looking at an aircraft, it is easy to observe that they have a number of common features: wings, a tail with vertical and horizontal wing sections, engines to propel them through the air, and a fuselage to carry passengers or cargo. If, however, you take a more critical look beyond the gross features, you also can see subtle, and sometimes not so subtle, differences. The reasons for these differences, why the designers configured them this way, is quite an intriguing study. Today, 100,000 flights will safely crisscross the planet. At no time in history have our lives been so global and full of possibility. -
Equations for the Application of to Pitching Moments
https://ntrs.nasa.gov/search.jsp?R=19670002485 2020-03-24T02:43:10+00:00Z View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NASA Technical Reports Server NASA TECHNICAL NOTE NASA TN D-3738 00 M h U GPO PRICE $ c/l U z CFSTl PRICE@) $ ,2biJ I 1 Hard copy (HC) ' (THRU) :: N67(ACCES~ION 11814NUMBER) 5P Microfiche (MF) > Jo(PAGES1 k i ff 853 July 85 2 (NASA CR OR TMX OR AD NUMBER) '- ! EQUATIONS FOR THE APPLICATION OF * WIND-TUNNEL WALL CORRECTIONS TO PITCHING MOMENTS CAUSED BY THE TAIL OF AN AIRCRAFT MODEL by Harry He Heyson Langley Research Center Langley Stdon, Hampton, Vk NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON, D. C. NOVEMBER 1966 . NASA TN D-3738 EQUATIONS FOR THE APPLICATION OF WIND-TUNNEL WALL CORRECTIONS TO PITCHING MOMENTS CAUSED BY THE TAIL OF AN AIRCRAFT MODEL By Harry H. Heyson Langley Research Center Langley Station, Hampton, Va. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION For sale by the Clearinghouse for Federal Scientific and Technical Information Springfield, Virginia 22151 - Price 61.00 , EQUATIONS FOR THE APPLICATION OF WIND-TUNNEL WALL CORmCTIONS TO PITCHING MOMENTS CAUSED BY THE TAIL OF AN AIRCRAFT MODEL By Harry H. Heyson Langley Research Center SUMMARY Equations are derived for the application of wall corrections to pitching moments due to the tail in two different manners. The first system requires only an alteration in the observed pitching moment; however, its application requires a knowledge of a number of quantities not measured in the usual wind- tunnel tests, as well as assumptions of incompressible flow, linear lift curves, and no stall. -
Introduction to Aircraft Stability and Control Course Notes for M&AE 5070
Introduction to Aircraft Stability and Control Course Notes for M&AE 5070 David A. Caughey Sibley School of Mechanical & Aerospace Engineering Cornell University Ithaca, New York 14853-7501 2011 2 Contents 1 Introduction to Flight Dynamics 1 1.1 Introduction....................................... 1 1.2 Nomenclature........................................ 3 1.2.1 Implications of Vehicle Symmetry . 4 1.2.2 AerodynamicControls .............................. 5 1.2.3 Force and Moment Coefficients . 5 1.2.4 Atmospheric Properties . 6 2 Aerodynamic Background 11 2.1 Introduction....................................... 11 2.2 Lifting surface geometry and nomenclature . 12 2.2.1 Geometric properties of trapezoidal wings . 13 2.3 Aerodynamic properties of airfoils . ..... 14 2.4 Aerodynamic properties of finite wings . 17 2.5 Fuselage contribution to pitch stiffness . 19 2.6 Wing-tail interference . 20 2.7 ControlSurfaces ..................................... 20 3 Static Longitudinal Stability and Control 25 3.1 ControlFixedStability.............................. ..... 25 v vi CONTENTS 3.2 Static Longitudinal Control . 28 3.2.1 Longitudinal Maneuvers – the Pull-up . 29 3.3 Control Surface Hinge Moments . 33 3.3.1 Control Surface Hinge Moments . 33 3.3.2 Control free Neutral Point . 35 3.3.3 TrimTabs...................................... 36 3.3.4 ControlForceforTrim. 37 3.3.5 Control-force for Maneuver . 39 3.4 Forward and Aft Limits of C.G. Position . ......... 41 4 Dynamical Equations for Flight Vehicles 45 4.1 BasicEquationsofMotion. ..... 45 4.1.1 ForceEquations .................................. 46 4.1.2 MomentEquations................................. 49 4.2 Linearized Equations of Motion . 50 4.3 Representation of Aerodynamic Forces and Moments . 52 4.3.1 Longitudinal Stability Derivatives . 54 4.3.2 Lateral/Directional Stability Derivatives . -
Landing Gear.Pdf
Study of Evolution and Details of Landing Gear INDEX CHAPTER 1 1.1.1 INTRODUCTION 3 1.1.2 EVOLUTION 3 CHAPTER 2 2.1 DIFFERENT TYPES OF LANDING GEARS 6 2.1.1 TRICYCLE LANDING GEAR 7 2.1.2 CONVENTIONAL LANDING GEAR 7 2.1.3 UNCONVENTIONAL LANDING GEAR 8 2.2 DIFFERENCE BETWEEN MAIN AND NOSE LANDING GEAR 9 2.3 SHOCK STRUTS 10 2.3.1 TYPES OF SHOCK STRUTS 1. METERING PIN TYPE 10 2. METERING TUBE TYPE 11 3. NOSE GEAR STRUTS 12 4. DOUBLE-ACTING SHOCK ABSORBER 12 2.4 OPERATION OF SHOCK STRUTS 13 CHAPTER 3 3.1 HYDRAULIC SYSTEM FOR AIRCRAFT LANDING GEAR 15 3.2 LANDING GEAR EXTENSION AND RETRACTION 15 3.2.1 LANDING GEAR EXTENSION AND RETRACTING MECHANISMS 15 3.3 EMERGENCY SYSTEMS 16 NIMRA INSTITUTE OF SCIENCE & TECHNOLOGY, A.E - 1 - Study of Evolution and Details of Landing Gear CHAPTER 4 4.1 BRAKING SYSTEM IN LANDING GEAR 18 4.2 DIFFERENT TYPES OF BRAKES AND THEIR EVOLUTION 4.2.1 CARBON AND BERYLLIUM BRAKES 18 4.2.2 AUTO-BRAKE AND BRAKE-BY-WIRE SYSTEM 19 4.3 DESCRIPTION OF A HYDRAULIC BRAKING SYSTEM 20 4.4 ADVANCED BRAKE CONTROL SYSTEM (ABCS) 21 4.5 PNEUMATIC BRAKING 21 4.6 DIFFERENTIAL BRAKING 22 CHAPTER 5 LUBRICANTS USED IN LANDING GEAR 23 CONCLUSION 24 REFERENCES 25 FIGURES FIG. 1 LANDING GEARS IN THE INITIAL STAGES 26 FIG. 2 BASIC TYPES OF LANDING GEARS 26 FIG. 3 TU-144 MAIN LANDING GEAR 27 FIG. 4 TRACK-TYPE GEAR 27 FIG.