# Twist Distributions for Swept Wings, Part 1

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 On the Wing... #161 Twist Distributions for Swept Wings, Part 1 Our curiosity got the better of us, and we asked Why are designers of swept wing tailless models placing proportionally more twist in the outboard portion of the wing? This series of articles will provide a comprehensive answer to that question. Our intense interest in tailless aircraft now spans twenty years. Over those two decades, we have built a number of plank type wings and several swept wings. As we explained in a recent column, there are advantages and disadvantages to both of these planforms. An introduction to twist distributions The impetus to begin designing our own swept wing tailless aircraft was the presentation given by Dr. Walter Panknin at the MARCS (Madison Area Radio Control Society) Symposium held in Dr. Panknin provided a relatively simple method for determining the geometric twist required for a stable planform when given the span, the root and tip chord lengths, the root and tip airfoil zero lift angles and pitching moments, the sweep angle of the quarter chord line, the design coefficient of lift, and the static margin. Dr. Panknin assumed that the wing twist would be imparted across the semi-span. That is, the root would be held at zero degrees and the tip twisted at some angle of washout, with the wing leading and trailing edges forming straight lines. Dr. Panknin s wing, the Flying Rainbow, along with Kurt Weller s Elfe II, utilized this type of twist distribution on tapered wings. In looking at other swept wings of that time period, we were also attracted to Hans-Jürgen Unverferth s CO2. The CO2 was different from the Flying Rainbow and the Elfe II in that the wing was not tapered but rather of constant chord. Additionally, CO2 utilizes a twist distribution in which the inner half of the semi-span has no twist at all. All of the geometric twist is in the outer half of the semi-span. While the actual twist angle is identical to that computed for the Panknin twist distribution, pitch stability is not adversely affected and in fact may be slightly better. More recently, Hans Jürgen and other swept wing designers have taken to imparting wing twist across three segments. From the root to one third of the semi-span there is no twist. About one third of the total twist is then put into the second third of the semi-span, and the remaining two thirds of the total twist is put into the wing between two thirds semi-span and the wing tip. Our curiosity got the better of us and we asked, Why are designers of swept wing tailless models placing proportionally more twist in the outboard portion of the wing? This series of articles will provide a comprehensive answer to that question. Page 1 of 10

2 Lift distributions Nearly all aerodynamics text books devote pages to what is called the lift distribution. The lift distribution for any straight (quarter chord line at 90 degrees to the centerline) wing can be graphically represented by a curved line superimposed over a standard X-Y coordinate system. The lift distribution curve traces the local circulation the local coefficient of lift times the local geometric chord. How is the lift distribution determined? Let s start by taking a look at the construction of the elliptical lift distribution. Assign the aircraft wing tips to the points 1.0 and -1.0 on the Y-axis of the coordinate system. Draw a circular arc above the Y-axis using the aircraft wing tips to define the diameter. A semicircle is formed which has the radius b/2 (the semi-span) and the area π/2(b/2) 2 which in this specific case is simply π/2 = Now drop vertical lines from the semicircle circumference to the Y-axis. Mark the mean (halfway) point on each vertical. Connecting these identified points creates an ellipse. (See Figure 1). This elliptical lift distribution is predominantly promoted as being the ideal, as represented in the planform of the British Supermarine Spitfire fighter of the World War II era. Why would the designer want the lift distribution of his arbitrary wing to closely match that of the elliptical lift distribution? Because with the elliptical lift distribution, a discovery of Ludwig Prandtl in 1908 which he published in 1920, each small area of the wing is carrying an identical load and so is operating at the same local coefficient of lift, the downwash off the trailing edge of the wing is constant across the span, and the coefficient of induced drag (drag due to lift) is at its minimum point. To construct the lift distribution for an arbitrary wing without twist or sweep, lay out the wing outline over the elliptical lift distribution with chord lengths proportioned such that the area of the wing is equal to that of the ellipse (one half that of the semicircle, in this case π/4 = 0.785). Draw a curve along the mean of the ellipse and the wing planform outline. (See Figure 2.) With some graphical experimentation, we find that the lift distribution for a wing with a taper ratio of 0.45 almost exactly matches that of the elliptical lift distribution described by Prandtl. (See Figure 3.) The tapered planform has at least one advantage over the elliptical planform it s far easier to build. But the elliptical planform has a stall pattern in which the entire wing is subject to stalling at the same time. At high angles of attack, small gusts can serve to trigger a stall on any portion of the wing span. A tapered wing with a nearly identical lift distribution will tend to behave in the same way. Lift coefficient distributions As stated previously, the lift generated by any wing segment is directly proportional to the coefficient of lift and the local geometric chord. This means that there is also a coefficient of lift distribution. For Prandtl s elliptical wing lift distribution, as has been described here, the local coefficient of lift is identical across the span. On the other hand, if the taper ratio is zero (the wing tip comes to a point), the coefficient of lift at the wing tip will be zero only in a truly vertical dive, Page 2 of 10

3 but otherwise it will be infinite because the wing tip chord is nil. Any time this wing is called upon to produce lift, the wing tip will be stalled. From this extreme example, we realize the tip chord cannot be too small, as it will then be forced to operate at a higher coefficient of lift, leading to a local stalling of the wing. (See Figure 4.) So called tip stalling can be inhibited by one or both of two methods. The first involves increasing the local chord near the wing tip, the second consists of imparting washout. As we intuitively know, enlarging the wing tip chord reduces the local coefficient of lift. An enlarged wing tip chord is not so efficient as the true elliptical planform, but the penalty for using a perfectly rectangular wing is just 7% and so it may be an acceptable trade-off for a machine designed for sport flying. Washout, on the other hand, while also reducing the coefficient of lift in the area of the wing tip, is good for only one speed. As the twist angle increases, the deleterious effects become stronger much more quickly as the coefficient of lift for the entire wing, C L, moves away from the design point. If washout is too great, the wing tips can actually be lifting downward at high speeds. This puts tremendous loads on the wing structure. Adverse yaw One other effect of utilizing the elliptical lift distribution comes about as we add control surfaces to the wing. Outboard ailerons, for example, create different coefficients of induced drag depending on whether the surface is moved up or down. The control surface moving downward creates more lift and hence more drag than the surface moving upward. When rolling into a turn, therefore, the aircraft is forced into a yaw away from the direction of the turn. (See Figure 5.) In conventional aircraft, this tendency can be reduced to some extent by what is called aileron differential. The upgoing control surface travels through a larger arc than the downgoing surface. While this tends to increase the drag on the downgoing wing, reducing adverse yaw to a great extent, many pilots find that some amount of rudder input is necessary to obtain a coordinated turn. Reduction of rudder input is an important consideration in the quest to reduce overall drag while maneuvering, but the associated induced drag from the fin and rudder, a low aspect ratio flying surface, cannot be entirely avoided. For a swept flying wing without vertical surface, elimination of adverse yaw is obviously imperative, but aileron differential cannot be used in this case because of its effect on pitch trim. Some other means of eliminating adverse yaw must be devised. Three major problems And so we are forced to solve three problems when designing a tailless aircraft: 1. achieve and hopefully surpass the low induced drag as exemplified by the elliptical lift distribution without creating untoward stall characteristics, 2. reduce the adverse yaw created by aileron deflection without adversely affecting the aircraft in pitch, and Page 3 of 10

4 3. maintain an acceptable weight to strength ratio. A relevant historical tidbit The Wright brothers, along with their other accomplishments, were the first aircraft designers to determine that banking was necessary to turn, an idea which no doubt came from their experience with bicycles. While other early aviation pioneers had studied bird flight, the perspective of the Wrights while watching birds was very much different because of their cycling experiences. (Interestingly, their direct competitor, Glenn Curtiss, built and raced motorcycles.) The Wrights also had the ability to separate the major problem of controlled powered flight into manageable components. Propulsion was separated from the production of lift, and stability was separated from control, for example. In fact, their solution to the problem of flight incorporated only one integrated system, the wing, which provided lateral control, structure, and lift. It was Wilbur s twisting of the inner-tube box, through which the idea of wing warping was derived and the internal bracing of their wing structure was devised, which provided the insight needed to create a controllable flying machine capable of carrying a human pilot/passenger. But the flying machine they created, while tremendously successful, for all practical purposes ended the use of birds as models for aircraft design. As an indicator of this, the Wrights saw their early successes and records in powered flight quickly surpassed by the inventions of others. Curtiss, for example, solved the problem of banking turns with separate control surfaces rather than wing warping. His aileron system is still in use today. The Wright s separation of a huge problem into smaller more easily solved problems has continued to be the hallmark of aircraft design for 100 years, and aviation has made nearly unbelievable strides during that century. But there are a growing number of aircraft designers who wish to go back to the bird model. They wish to design an aircraft which is the minimum required for efficient controlled flight by integrating lift, stability and control into a single structural component. A bird is a biological system which has been very successful for a very long time. To be successful in the competitive environment of nature, a flying bird needs more than just lift, stability, and control. A bird must also be efficient at flying. That is, it must have a very low energy expenditure. Minimum drag while moving through the air is of course of major importance in this regard, as is a very light airframe because extra weight increases the energy drain on the system. We can see through direct observation that birds have no vertical surfaces, yet birds are able to make beautiful coordinated banked turns without any evidence of adverse yaw. Perhaps birds do not make use of Prandtl s elliptical lift distribution. What s next? As a prelude to future installments, let us ask a series of provocative questions: Page 4 of 10

5 What if we found that the elliptical lift distribution does not lead to the minimum induced drag, as has been dogma in most aerodynamics texts since Prandtl introduced the concept in 1920? What if we found a way to produce induced thrust in addition to, and without increasing, the induced drag produced by the creation of lift? What if we could increase the wing span and aspect ratio without increasing the required strength of the spar at the wing root? What if the answers to all of the above questions are related? We ll cover all of this and more in future installments! Ideas for future columns are always welcome. RCSD readers can contact us by mail at P.O. Box 975, Olalla WA , or by at References: Anderson, John D. Jr. Introduction to flight. McGraw-Hill, New York, Anderson, John D. Jr. Fundamentals of aerodynamics. McGraw-Hill, New York, Bowers, Al. Correspondence within < list. Hoerner, Dr.-Ing. S.F. and H.V. Borst. Fluid-dynamic lift. Hoerner fluid dynamics, Vancouver WA USA, Horten, Dr. Reimar. Lift distribution on flying wing aircraft. Soaring June 1981, pp Hurt, H.H. Jr. Aerodynamics for naval aviators. Published as NAVWEPS 00-80T-80 by the U.S. Navy, Kermode, A.C. Mechanics of flight. Pitman, London, McCormick, Barnes W. Aerodynamics, aeronautics, and flight mechanics. John Wiley and Sons, New York, Raymer, Daniel P. Aircraft design: a conceptual approach. AIAA Education Series, Washington, DC, Shevell, Richard S. Fundamentals of flight. Prentice-Hall, Englewood Cliffs NJ USA, Simons, Martin. Model aircraft aerodynamics. Argus Books, Hemel Hempstead Great Britain, The White Sheet, Spring 1986, No. 36. Sean Walbank editor. White Sheet Radio Flying Club, Dorset/Somerset Great Britain. Page 5 of 10

6 X semi-circle ellipse -Y -1 0 b b/2 +1 +Y Figure 1. Construction of elliptical lift distribution Page 6 of 10

7 X ellipse -Y -1 0 b b/2 +1 +Y Figure 2. Construction of lift distribution for untwisted rectangular wing. Page 7 of 10

8 X ellipse -Y -1 0 b b/2 +1 +Y Figure 3. Construction of lift distribution for untwisted wing with taper ratio of Page 8 of 10

9 shape Lift CL downwash Figure 4. Three wing planforms and their associated lift distributions, coefficient of lift distributions, and downwash distributions. Page 9 of 10

10 Figure 5a. Lift and drag profiles for untwisted rectangular wing in straight and level flight and no control surface deflection. roll to left yaw to right Figure 5b. Lift and drag profiles for untwisted rectangular wing with aileron deflection for left bank, no differential. Page 10 of 10

### Twist Distributions for Swept Wings, Part 1

On the Wing... #161 Twist Distributions for Swept Wings, Part 1 Our curiosity got the better of us, and we asked Why are designers of swept wing tailless models placing proportionally more twist in the

### Twist Distributions for Swept Wings, Part 2

On the Wing... #162 Twist Distributions for Swept Wings, Part 2 Having defined and provided examples of lift distributions in Part 1, we now move on to describing the stalling patterns of untwisted and

### Jet Propulsion. Lecture-17. Ujjwal K Saha, Ph. D. Department of Mechanical Engineering Indian Institute of Technology Guwahati

Lecture-17 Prepared under QIP-CD Cell Project Jet Propulsion Ujjwal K Saha, Ph. D. Department of Mechanical Engineering Indian Institute of Technology Guwahati 1 Lift: is used to support the weight of

### Lift 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

### Flying Wings. By Henry Cole

Flying Wings By Henry Cole FLYING WINGS REPRESENT THE THEORETICAL ULTIMATE IN AIRCRAFT DESIGN. USE THESE IDEAS, AVAILABLE AFTER A YEAR, OF RESEARCH, TO DEVELOP PRACTICAL MODELS. The rubber version of this

### Principles of glider flight

Principles of glider flight [ Lecture 2: Control and stability ] Richard Lancaster Email: Richard@RJPLancaster.net Twitter: @RJPLancaster ASK-21 illustrations Copyright 1983 Alexander Schleicher GmbH &

### Homework Exercise to prepare for Class #2.

Homework Exercise to prepare for Class #2. Answer these on notebook paper then correct or improve your answers (using another color) by referring to the answer sheet. 1. Identify the major components depicted

### Chapter 5 Wing design - selection of wing parameters - 3 Lecture 21 Topics

Chapter 5 Wing design - selection of wing parameters - 3 Lecture 21 Topics 5.3.2 Choice of sweep ( ) 5.3.3 Choice of taper ratio ( λ ) 5.3.4 Choice of twist ( ε ) 5.3.5 Wing incidence(i w ) 5.3.6 Choice

### II.E. Airplane Flight Controls

References: FAA-H-8083-3; FAA-8083-3-25 Objectives Key Elements Elements Schedule Equipment IP s Actions SP s Actions Completion Standards The student should develop knowledge of the elements related to

### Flight Control Systems Introduction

Flight Control Systems Introduction Dr Slide 1 Flight Control System A Flight Control System (FCS) consists of the flight control surfaces, the respective cockpit controls, connecting linkage, and necessary

### Fighter aircraft design. Aerospace Design Project G. Dimitriadis

Fighter aircraft design Aerospace Design Project 2017-2018 G. Dimitriadis General configuration The elements of the general configuration are the following: Wing Wing placement Airfoil Number of engines

### PRIMARY FLIGHT CONTROLS. AILERONS Ailerons control roll about the longitudinal axis. The ailerons are attached to the outboard trailing edge of

Aircraft flight control systems are classified as primary and secondary. The primary control systems consist of those that are required to safely control an airplane during flight. These include the ailerons,

### Aerobatic Trimming Chart

Aerobatic Trimming Chart From RCU - Chip Hyde addresses his view of Engine/Motor thrust. I run almost no right thrust in my planes and use the thottle to rudd mix at 2% left rudd. to throttle at idle.

### PILOT S HANDBOOK of Aeronautical Knowledge AC61-23C

PILOT S HANDBOOK of Aeronautical Knowledge AC61-23C Revised 1997 Chapter 1 Excerpt Compliments of... www.alphatrainer.com Toll Free: (877) 542-1112 U.S. DEPARTMENT OF TRANSPORTATION FEDERAL AVIATION ADMINISTRATION

### TECHNICAL ARTICLE STUNT KITE AERODYNAMICS

TECHNICAL ARTICLE STUNT KITE AERODYNAMICS Written March 16, 1998 Updated January 26, 2010 By DOUGLAS K. STOUT "DESIGNING FOR THE FUTURE" 50 OLD STAGE COACH ROAD ANDOVER, NEW JERSEY 07821 (973) 786-7849

### Induced Drag Reduction for Modern Aircraft without Increasing the Span of the Wing by Using Winglet

International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:10 No:03 49 Induced Drag Reduction for Modern Aircraft without Increasing the Span of the Wing by Using Winglet Mohammad Ilias

### Preliminary Analysis of Drag Reduction for The Boeing

Preliminary Analysis of Drag Reduction for The Boeing 747-400 By: Chuck Dixon, Chief Scientist, Vortex Control Technologies LLC 07. 31. 2012 Potential for Airflow Separation That Can Be Reduced By Vortex

### CIRCLING THE HOLIGHAUS WAY -

CIRCLING THE HOLIGHAUS WAY - OR DO YOU REALLY WANT TO KEEP THE YAW STRING CENTERED? BY RICHARD H. JOHNSON ANSWERS: 1. During Straight Flight - YES, that minimizes drag and maximizes the sailplane's performance.

### THEORY OF WINGS AND WIND TUNNEL TESTING OF A NACA 2415 AIRFOIL. By Mehrdad Ghods

THEORY OF WINGS AND WIND TUNNEL TESTING OF A NACA 2415 AIRFOIL By Mehrdad Ghods Technical Communication for Engineers The University of British Columbia July 23, 2001 ABSTRACT Theory of Wings and Wind

### Low-Speed Wind-Tunnel Investigation of the Stability and Control Characteristics of a Series of Flying Wings With Sweep Angles of 50

NASA Technical Memorandum 464 Low-Speed Wind-Tunnel Investigation of the Stability and Control Characteristics of a Series of Flying Wings With Sweep Angles of 5 Scott P. Fears Lockheed Engineering & Sciences

### PERFORMANCE MANEUVERS

Ch 09.qxd 5/7/04 8:14 AM Page 9-1 PERFORMANCE MANEUVERS Performance maneuvers are used to develop a high degree of pilot skill. They aid the pilot in analyzing the forces acting on the airplane and in

### AIRCRAFT STRUCTURAL DESIGN & ANALYSIS K. RAMAJEYATHILAGAM

AIRCRAFT STRUCTURAL DESIGN & ANALYSIS K. RAMAJEYATHILAGAM To invent an airplane is nothing To build one is something But to fly is everything Lilienthal DAY 1 WHAT IS AN AIRCRAFT? An aircraft is a vehicle,

### THE DESIGN OF WING SECTIONS

THE DESIGN OF WING SECTIONS Published in "Radio Control Model News" Issue Number 8 Winter 93 Aerofoil section design has advanced a great deal since great pioneers like Horatio Phillips experimented with

### Improved Aerodynamic Characteristics of Aerofoil Shaped Fuselage than that of the Conventional Cylindrical Shaped Fuselage

International Journal of Scientific & Engineering Research Volume 4, Issue 1, January-213 1 Improved Aerodynamic Characteristics of Aerofoil Shaped Fuselage than that of the Conventional Cylindrical Shaped

### WHAT IS GLIDER? A light engineless aircraft designed to glide after being towed aloft or launched from a catapult.

GLIDER BASICS WHAT IS GLIDER? A light engineless aircraft designed to glide after being towed aloft or launched from a catapult. 2 PARTS OF GLIDER A glider can be divided into three main parts: a)fuselage

### April, Vol. 19, No. 4 U.S.A. \$3.50. Page 1. April 2002

April, 2002 Vol. 19, No. 4 U.S.A. \$3.50 April 2002 Page 1 ABOUT RCSD R /C Soaring Digest (RCSD) is a readerwritten monthly publication for the R/C sailplane enthusiast and has been published since January,

### PRE-TEST Module 2 The Principles of Flight Units /60 points

PRE-TEST Module 2 The Principles of Flight Units 1-2-3.../60 points 1 Answer the following questions. (20 p.) moving the plane (4) upward / forward. Opposed to that is 1. What are the names of the four

### Aerofoil Profile Analysis and Design Optimisation

Journal of Aerospace Engineering and Technology Volume 3, Issue 2, ISSN: 2231-038X Aerofoil Profile Analysis and Design Optimisation Kondapalli Siva Prasad*, Vommi Krishna, B.B. Ashok Kumar Department

### TAKEOFF & LANDING IN ICING CONDITIONS

Original idea from Captain A. Wagner T TAKEOFF & LANDING IN ICING CONDITIONS here have been a number of accidents related to take-off in conditions in which snow and/or other forms of freezing precipitation

### AE Stability and Control of Aerospace Vehicles

AE 430 - Stability and Control of Aerospace Vehicles Introduction 1 Welcome to AE 430 - Stability and Control of Aerospace Vehicles Pier Marzocca Pier CAMP 234, MAE Department MW 10:00-12:30, CAMP 234

### BASIC AIRCRAFT STRUCTURES

Slide 1 BASIC AIRCRAFT STRUCTURES The basic aircraft structure serves multiple purposes. Such as aircraft aerodynamics; which indicates how smooth the aircraft flies thru the air (The Skelton of the aircraft

### Aerofoil Design for Man Powered Aircraft

Man Powered Aircraft Group Aerofoil Design for Man Powered Aircraft By F. X. Wortmann Universitat Stuttgart From the Second Man Powered Aircraft Group Symposium Man Powered Flight The Way Ahead 7 th February

### Improvement of an Artificial Stall Warning System for Sailplanes

Improvement of an Artificial Stall Warning System for Sailplanes Loek M. M. Boermans and Bart Berendsen Delft University of Technology, Faculty of Aerospace Engineering P.O.Box 5058, 2600 GB Delft, The

### Spins and how to keep the pointy end of the airplane going forward

Spins and how to keep the pointy end of the airplane going forward 8/14/07 Evan Reed, cfievan@yahoo.com Ed Williams Outline Spins and their general characteristics Accident statistics and scenarios Some

### Aerospace Design Project. Design of a class-3 Ultralight airplane

Aerospace Design Project Design of a class-3 Ultralight airplane Ludovic Noels Grigorios Dimitriadis L.Noels@ulg.ac.be gdimitriadis@ulg.ac.be 1. Context Groups from 4 to 5 students will design a class-3

### Air Craft Winglet Design and Performance: Cant Angle Effect

Journal of Robotics and Mechanical Engineering Research Air Craft Winglet Design and Performance: Cant Angle Effect Eslam Said Abdelghany 1, Essam E Khalil 2*, Osama E Abdellatif 3 and Gamal elhariry 4

### AC : FORCE BALANCE DESIGN FOR EDUCATIONAL WIND TUNNELS

AC 2010-393: FORCE BALANCE DESIGN FOR EDUCATIONAL WIND TUNNELS Martin Morris, Bradley University Martin Morris is a professor of Mechanical Engineering at Bradley University in Peoria, IL. He worked for

### Flight Controls. Chapter 5. Introduction

Chapter 5 Flight Controls Introduction This chapter focuses on the flight control systems a pilot uses to control the forces of flight, and the aircraft s direction and attitude. It should be noted that

### 1. A tendency to roll or heel when turning (a known and typically constant disturbance) 2. Motion induced by surface waves of certain frequencies.

Department of Mechanical Engineering Massachusetts Institute of Technology 2.14 Analysis and Design of Feedback Control Systems Fall 2004 October 21, 2004 Case Study on Ship Roll Control Problem Statement:

### Building Good Habits for a Better Future Aileron-Rudder Mixing Explained

Building Good Habits for a Better Future Aileron-Rudder Mixing Explained By Dave Scott. Instructor, 1st U.S. R/C Flight School Illustrations by Dave Scott Adverse Yaw Introduction The following article

### HOW AND WHY DO GLIDERS FLY - WHAT SHAPE SHOULD THEY BE?

HOW AND WHY DO GLIDERS FLY - WHAT SHAPE SHOULD THEY BE? What is flight? We all understand that air is a fluid, not dissimilar to, if lighter than, water, and we can all appreciate that an immerse body

### HIGH ALTITUDE AERODYNAMICS

HIGH ALTITUDE AERODYNAMICS CRITICAL ASPECTS OF MACH FLIGHT In recent years, a number of corporate jet airplanes have been involved in catastrophic loss of control during high-altitude/high-speed flight.

### Numerical Analysis of Wings for UAV based on High-Lift Airfoils

Numerical Analysis of Wings for UAV based on High-Lift Airfoils Sachin Srivastava Department of Aeronautical Engineering Malla Reddy College of Engineering & Technology, Hyderabad, Telangana, India Swetha

### Theory of Flight Aircraft Design and Construction. References: FTGU pages 9-14, 27

Theory of Flight 6.01 Aircraft Design and Construction References: FTGU pages 9-14, 27 Main Teaching Points Parts of an Airplane Aircraft Construction Landing Gear Standard Terminology Definition The airplane

### Principles 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

### Big News! Dick Kline Inventor of the KF AirFoil Contacts rcfoamfighters.

Big News! Dick Kline Inventor of the KF AirFoil Contacts rcfoamfighters. (Copy of Email from Dick Kline to rcfoamfighters on 3/28/09) --------------------------------------------------------------------------------

### High 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,

### Wind Energy Technology. What works & what doesn t

Wind Energy Technology What works & what doesn t Orientation Turbines can be categorized into two overarching classes based on the orientation of the rotor Vertical Axis Horizontal Axis Vertical Axis Turbines

### Aerodynamic characteristics around the stalling angle of the discus using a PIV

10TH INTERNATIONAL SYMPOSIUM ON PARTICLE IMAGE VELOCIMETRY PIV13 Delft, The Netherlands, July 1-3, 2013 Aerodynamic characteristics around the stalling angle of the discus using a PIV Kazuya Seo 1 1 Department

### STUDIES ON THE OPTIMUM PERFORMANCE OF TAPERED VORTEX FLAPS

ICAS 2000 CONGRESS STUDIES ON THE OPTIMUM PERFORMANCE OF TAPERED VORTEX FLAPS Kenichi RINOIE Department of Aeronautics and Astronautics, University of Tokyo, Tokyo, 113-8656, JAPAN Keywords: vortex flap,

### Aerodynamically Efficient Wind Turbine Blade S Arunvinthan 1, Niladri Shekhar Das 2, E Giriprasad 3 (Avionics, AISST- Amity University, India)

International Journal of Engineering Science Invention ISSN (Online): 2319 6734, ISSN (Print): 2319 6726 Volume 3 Issue 4ǁ April 2014ǁ PP.49-54 Aerodynamically Efficient Wind Turbine Blade S Arunvinthan

### LEADING-EDGE VORTEX FLAPS FOR SUPERSONIC TRANSPORT CONFIGURATION -EFFECTS OF FLAP CONFIGURATIONS AND ROUNDED LEADING-EDGES-

ICAS 2002 CONGRESS LEADING-EDGE VORTEX FLAPS FOR SUPERSONIC TRANSPORT CONFIGURATION -EFFECTS OF FLAP CONFIGURATIONS AND ROUNDED LEADING-EDGES- Kenichi RINOIE*, Dong Youn KWAK**, Katsuhiro MIYATA* and Masayoshi

### Howard Torode. Member of General Aviation Group and Chairman BGA Technical Committee

Efficient Light Aircraft Design Options from Gliding Howard Torode Member of General Aviation Group and Chairman BGA Technical Committee Presentation Aims Recognise the convergence of interest between

### IMPACT OF FUSELAGE CROSS SECTION ON THE STABILITY OF A GENERIC FIGHTER

IMPACT OF FUSELAGE CROSS SECTION ON THE STABILITY OF A GENERIC FIGHTER Robert M. Hall NASA Langley Research Center Hampton, Virginia ABSTRACT Many traditional data bases, which involved smooth-sided forebodies,

### EXPERIMENTAL INVESTIGATION OF THE AERODYNAMIC CHARACTERISTICS OF A K TANDEM CONFIGURATION

EXPERIMENTAL INVESTIGATION OF THE AERODYNAMIC CHARACTERISTICS OF A K TANDEM CONFIGURATION João Barbosa * & Jorge Gonçalves & Pedro Gamboa Department of Aerospace Sciences Universidade da Beira Interior

### Stalls and Spins. Tom Johnson CFIG

Stalls and Spins Tom Johnson CFIG Do we need all of this? Lift The force created by moving the wing through the air. Angle of Attack: The angle between the relative wind and the wing chord line. Stalls

### Airplane controls. The three primary flight controls are the ailerons, elevator and rudder.

Airplane controls The three primary flight controls are the ailerons, elevator and rudder. Ailerons: The two ailerons, one at the outer trailing edge of each wing, are movable surfaces that control movement

### Aerodynamic investigation of Winglets on Wind Turbine Blades using CFD

Risø-R-1543(EN) Aerodynamic investigation of Winglets on Wind Turbine Blades using CFD Jeppe Johansen and Niels N. Sørensen Risø National Laboratory Roskilde Denmark February 26 Author: Jeppe Johansen

### Figure 1. Curtis 1911 model D type IV pusher

This material can be found in more detail in Understanding Flight 1 st and 2 nd editions by David Anderson and Scott Eberhardt, McGraw-Hill, 2001, and 2009 A Physical Description of Flight; Revisited David

### Attitude Instrument Flying and Aerodynamics

Attitude Instrument Flying and Aerodynamics 2.1 TURNS 1. An airplane requires a sideward force to make it turn. a. When the airplane is banked, lift (which acts perpendicular to the wingspan) acts not

### BOEING COMMERCIAL AIRPLANE GROUP FLIGHT OPERATIONS TECHNICAL BULLETIN

BOEING COMMERCIAL AIRPLANE GROUP FLIGHT OPERATIONS TECHNICAL BULLETIN NUMBER: 707 717 727 737 747 02-1 B-717-02-09 02-1 02-2 13 747-400 757 767 777 DC-8 50 68 68 10 DC-8-02-01 DC-9 DC-10 MD-80 MD-90 MD-10

### Maximum Rate Turns. Objective To carry out a balanced, maximum rate, level turn using full power.

Advanced Manoeuvres Maximum Rate Turns To achieve the maximum rate of turn, the greatest possible force toward the centre of the turn is required. This is achieved by inclining the lift vector as far as

### file://c:\program Files\Microsoft Games\Microsoft Flight Simulator X\FSWeb\lessons\Stud...

Page 1 of 7 Lesson 2: Turns How Airplanes Turn Fly This Lesson Now by Rod Machado There are many misconceptions in aviation. For instance, there are pilots who think propwash is a highly specialized detergent.

### Part 66 Cat. B1 / B2 Module 8 BASIC AERODYNAMICS. Vilnius Issue 1. Effective date FOR TRAINING PURPOSES ONLY Page 1 of 74

Part 66 Cat. B1 / B2 Module 8 BASIC AERODYNAMICS Vilnius-2017 Issue 1. Effective date 2017-07-28 FOR TRAINING PURPOSES ONLY Page 1 of 74 Table of Contents Part-66 Module 8. Basic Aerodynamics (Cat. B1

### Study on Bi-Plane Airfoils

Study on Bi-Plane Airfoils Experiment 5: Final Design Project MECHANICAL AEROSPACE ENGINEERING 108 WINDTUNNEL LAB Professor Gamero-Castaño cc: Rayomand Gundevia Date: 12/09/13 Jin Mok 49832571 1 Abstract...

### 1. GENERAL AERODYNAMICS

Chapter 1. GENERAL AERODYNAMICS Unless otherwise indicated, this handbook is based on a helicopter that has the following characteristics: 1 - An unsupercharged (normally aspirated) reciprocating engine.

### JOURNAL PUBLICATIONS

1 JOURNAL PUBLICATIONS 71. Lee, T., Mageed, A., Siddiqui, B. and Ko, L.S., (2016) Impact of ground proximity on aerodynamic properties of an unsteady NACA 0012 airfoil, submitted to Journal of Aerospace

### Aviation Merit Badge Knowledge Check

Aviation Merit Badge Knowledge Check Name: Troop: Location: Test Score: Total: Each question is worth 2.5 points. 70% is passing Dan Beard Council Aviation Knowledge Check 1 Question 1: The upward acting

### Learning Objectives 081 Principles of Flight

Learning Objectives 081 Principles of Flight Conventions for questions in subject 081. 1. The following standard conventions are used for certain mathematical symbols: * multiplication. > = greater than

### DYNAMIC STALL AND CAVITATION OF STABILISER FINS AND THEIR INFLUENCE ON THE SHIP BEHAVIOUR

DYNAMIC STALL AND CAVITATION OF STABILISER FINS AND THEIR INFLUENCE ON THE SHIP BEHAVIOUR Guilhem Gaillarde, Maritime Research Institute Netherlands (MARIN), the Netherlands SUMMARY The lifting characteristics

### WIND TUNNEL MEASUREMENTS AND CALCULATIONS OF AERODYNAMIC INTERACTIONS BETWEEN TILTROTOR AIRCRAFT

WIND TUNNEL MEASUREMENTS AND CALCULATIONS OF AERODYNAMIC INTERACTIONS BETWEEN TILTROTOR AIRCRAFT Wayne Johnson Gloria K. Yamauchi Army/NASA Rotorcraft Division Moffett Field, California Michael R. Derby

### Beechcraft Duchess 76 Maneuver Notes

Beechcraft Duchess 76 Maneuver Notes I. Maneuver notes for Performance (AOA V), Slow Flight and Stalls (AOA VIII), Emergency Operations (AOA X), and Multiengine Operations (AOA XI) a. Maneuvers addressed:

### Transportation Engineering - II Dr. Rajat Rastogi Department of Civil Engineering Indian Institute of Technology - Roorkee. Lecture - 35 Exit Taxiway

Transportation Engineering - II Dr. Rajat Rastogi Department of Civil Engineering Indian Institute of Technology - Roorkee Lecture - 35 Exit Taxiway Dear students, we are back with the lecture series of

### Rigging the Pitts by Doug Sowder, IAC #14590

Rigging the Pitts by Doug Sowder, IAC #14590 Pitts not flying so straight anymore? Don t believe that a Pitts can fly hands-off? Maybe you need to set aside a Saturday and do some rigging. The maintenance

### THEORY OF GLIDER FLIGHT

THEORY OF GLIDER FLIGHT In 1988 the Soaring Society rewrote the Joy Of Soaring originally written by Carle Conway. I was asked to assist in the rewriting. The following revision is part of what I recommended.

### DRAG REDUCTION BY WING TIP SLOTS IN A GLIDING HARRIS HAWK, PARABUTEO UNICINCTUS

The Journal of Experimental Biology 198, 775 781 (1995) Printed in Great Britain The Company of Biologists Limited 1995 775 DRAG REDUCTION BY WING TIP SLOTS IN A GLIDING HARRIS HAWK, PARABUTEO UNICINCTUS

### Flightlab Ground School 7. Longitudinal Dynamic Stability

Flightlab Ground School 7. Longitudinal Dynamic Copyright Flight Emergency & Advanced Maneuvers Training, Inc. dba Flightlab, 2009. All rights reserved. For Training Purposes Only Introduction to is the

### Design and Integration of a Mechanical Aircraft Control System Mixer for Ruddervator Surfaces Advanced Tech Engineering, Inc.

Design and Integration of a Mechanical Aircraft Control System Mixer for Ruddervator Surfaces Advanced Tech Engineering, Inc. Requirements Design a control mechanism mixer that mechanically controls ailerons,

### Pentagon & Boeing 757 Ground Effect

Page 1 of 9 Pentagon & Boeing 757 Ground Effect In the aftermath of 9/11, I have heard many claims that a 757 could not possible have hit the Pentagon because the plane cannot fly so low to the ground

### Experimental Investigation of the Aerodynamics of a Modeled Dragonfly Wing Section

Region I-MA Student Conference AIAA - 2005 April 8-9, 2005 / Charlottesville, Virginia Experimental Investigation of the Aerodynamics of a Modeled Dragonfly Wing Section Michelle Kwok * and Rajat Mittal

### Figure 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

### Activity Parts of an Aircraft

Activity 4.2.7 Parts of an Aircraft Introduction The science of aeronautics really began to evolve in the late 18th and early 19th centuries. Philosophers and early scientists began to look closely at

### THERMALLING TECHNIQUES. Preface

DRAFT THERMALLING TECHNIQUES Preface The following thermalling techniques document is provided to assist Instructors, Coaches and Students as a training aid in the development of good soaring skills. Instructors

### Aircraft - Very Heavy Lift at Very Low Cost

Aircraft - Very Heavy Lift at Very Low Cost Stephen Funck This is a span loader for standard shipping containers. The design goal is the lowest cost per ton / mile. Low wing loading allows for low flight

### CFD SIMULATION STUDY OF AIR FLOW AROUND THE AIRFOIL USING THE MAGNUS EFFECT

Magnus effect, simulation, air flow Patryk SOKOŁOWSKI *, Jacek CZARNIGOWSKI **, Paweł MAGRYTA *** CFD SIMULATION STUDY OF AIR FLOW AROUND THE AIRFOIL USING THE MAGNUS EFFECT Abstract The article presents

### XII.A-D. Basic Attitude Instrument Flight

References: FAA-H-8083-3; FAA-8083-3-15 Objectives Key Elements Elements Schedule Equipment IP s Actions SP s Actions Completion Standards The student should develop knowledge of the elements related to

### Job Sheet 1 Blade Aerodynamics

Job Sheet 1 Blade Aerodynamics The rotor is the most important part of a wind turbine. It is through the rotor that the energy of the wind is converted into mechanical energy, which turns the main shaft

### G - LOAD Longitudinal Static Stability

GYROPLANE ASTM STANDARDS PART 5 G - LOAD Longitudinal Static Stability By Greg Gremminger Greg Gremminger has served as the Chairman of the ASTM Light Sport Aircraft Gyroplane subcommittee developing the

### The Influence of Spar Location on the Elastic Deformation and the Weight Estimation of a Swept-back, High Altitude, Solar Powered Flying Wing UAV

7 TH EUROPEAN CONFERENCE FOR AERONAUTICS AND SPACE SCIENCES (EUCASS) The Influence of Spar Location on the Elastic Deformation and the Weight Estimation of a Swept-back, High Altitude, Solar Powered Flying

### Longitudinal Stability of the Lancair 320/360 with Original and MKII Horizontal Stabilizers

Longitudinal Stability of the Lancair 320/360 with Original and MKII Horizontal C. Zavatson 4-23-2014, Rev B 1 Contents 2 Introduction... 4 2.1 Stability... 4 3 Objective and Test Approach... 5 4 Test

### The Design Improvement of Airfoil for Flying Wing UAV

WSEAS TRANSACTIONS on APPIED and THEORETICA ECHANICS The Design Improvement of Airfoil for Flying Wing UAV PRASETYO EDI, NUKAN YUSOFF and AZNIJAR AHAD YAZID Department of Engineering Design & anufacture,

### Effects of Duct Lip Shaping and Various Control Devices on the Hover and Forward Flight Performance of Ducted Fan UAVs. Will E.

Effects of Duct Lip Shaping and Various Control Devices on the Hover and Forward Flight Performance of Ducted Fan UAVs by Will E. Graf Thesis submitted to the faculty of Virginia Polytechnic Institute

### ENGINEERing challenge workshop for science museums in the field of aeronautic engineering

ENGINEERing challenge workshop for science museums in the field of aeronautic engineering 1 Index Workshop ID card...3 Specific unit objectives...4 Resources...4 The workshop...5 Introduction...5 The main

### Aerodynamics. Contact the National Museum of the U.S. Navy for Field Trip and School Visit opportunities!

Aerodynamics In this packet, we will be learning the basic physics behind how air balloons, airships, and airplanes fly! We are then going to practice these principles in easy and fun activities that can

### Study of a Swept Wing with Leading-Edge Ice Using a Wake Survey Technique

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 7-1 January 213, Grapevine (Dallas/Ft. Worth Region), Texas AIAA 213-245 Study of a Swept Wing with Leading-Edge

### Figure 1 Schematic of opposing air bearing concept

Theoretical Analysis of Opposing Air Bearing Concept This concept utilizes air bearings to constrain five degrees of freedom of the optic as shown in the figure below. Three pairs of inherently compensated

### CHAPTER 5 WING DESIGN

HAPTER 5 WING DESIGN Mohammad Sadraey Daniel Webster ollege Table of ontents hapter 5... 1 Wing Design... 1 5.1. Introduction... 1 5.. Number of Wings... 4 5.3. Wing Vertical Location... 5 5.3.1. High