...Abstract: In this experiment, the use of a scale model airfoil section of an aircraft wing will be analyzed in a wind tunnel. The basic physical laws of engineering and science shall be applied to verify and to understand the principles of flight. A dimensional analysis will be applied to the model airfoil to represent a full-scale wing prototype. The basics of aerodynamics, as applied to standard NACA airfoil configurations, shall be applied to establish performance data regarding lift, drag and stall with respect to the various angles attack demonstrated throughout the experiment at a number of air speeds. It should be noted that the Cessna 152 trainer aircraft uses a NACA 2412 airfoil, which is slightly thinner than the NASA 2415 airfoil currently available in this laboratory. Other airfoil models used in this laboratory include the NACA 4415 (normally used on the Lake Amphibious aircraft) and the NACA 0015 (used on helicopter blades and some acrobatic aircraft). The NACA 4415 is a very high lift airfoil designed to lift aircraft out of water quickly. Table of Content Abstract………..........................................................................................................................ii 1. Introduction....................................................................................................................4 2. Theory.......................................................................................................................
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...Miniature Aerial Vehicle – Airframe characterization R. Shivkumar, Hemendra Arya & K. Sudhakar Department of Aerospace Engineering Indian Institute of Technology Bombay Powai, Mumbai – 400076 e-mail: arya@aero.iitb.ac.in Abstract: Airframe design is an important step in the development of mini aerial vehicles. Airframe design means the shape and size of the aircraft. Issues related to mini aerial vehicle design are discussed in the paper. In this paper a case study of design of a 0.6 m fixed wing aerial vehicle is presented. This case study also brings out the requirement of various tools to conduct such an exercise. Introduction: Significant interest is being shown by academic institutions in research activities related to Remotely Piloted Vehicles (RPV’s) and Unmanned Aerial Vehicles (UAV’s). Flying platforms and their design with suitable payloads reinforce classroom education while exposing students to a host of flight related problems and issues of systems integration. There has been a long felt need to bring students, especially in the field of engineering, closer to the complexities and risks in dealing with actual systems. The Department of Aerospace Engineering, IIT Bombay has decided to make headway in this direction by developing remotely piloted aerial vehicles as experimental platforms[1]. The various disciplines required for such a design activity are aerodynamics, performance, structures, stability, control and propulsion. Each of these designs are different compared...
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...Ansys Workbench Basics Guide Suhail Mahmud and Mohamad Wissam Ansys Workbench Basics Guide Suhail Mahmud Mostafa Mohamad Wissam Farhoud December - 2013 1 Ansys Workbench Basics Guide Suhail Mahmud and Mohamad Wissam Abstract With the emerging importance of CFD and finite element analyses, it is of great necessity that engineering students get a good base of knowledge on one of the most used software packages in the industry of simulation, ANSYS. This brief tutorial states a few simple examples of the main applications of the software package ANSYS and highlights some of the possible problems students may face during their journey in discovering this application. The flow of information is structured that the reader gets an understanding of how important ANSYS is, and how it works and what type of machines are needed for the student level research expected. Then the tutorial goes on with simple straight forward examples of structural and fluid physics simulated using the ANSYS package. Eventually, the tutorial addresses the most important problems generally faced by the students such as unsuccessful meshing, or divergent solutions. Disclaimer It is extremely important to note two points while following this tutorial: The knowledge contained in this paper is by no means, accepted as mainstream, or an industry best practice. It is merely the product of the experience of senior engineering students who explored the program and desired to share their experience...
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...1. 1.1 2. 2.1 2.2 2.3 2.4 3. 3.1 3.2 3.3. 3.4. 4. INTRODUCTION................................................................................................. 2 OBJECTIVES ................................................................................................... 3 GROUND EFFECT AERODYNAMICS.............................................................. 4 CHORD DOMINATED GROUND EFFECT ................................................... 4 SPAN DOMINATED GROUND EFFECT....................................................... 5 AERODYNAMIC CENTERS IN GROUND EFFECT..................................... 6 AERODYNAMIC EFFICIENCY IN GROUND EFFECT ............................... 7 EKRANOPLANS.................................................................................................. 9 CONFIGURATION LAYOUT ......................................................................... 9 POWER AUGMENTATION RAM (PAR)..................................................... 12 LONGITUDINAL STABILITY...................................................................... 14 LATERAL STABILITY ................................................................................. 15 1. INTRODUCTION Wing-in-ground effect applies to vehicles design to fly at very low altitudes to take the advantage of increased in aerodynamic lift and reduced drag which occurs when a wing is in ground effect. The phenomenon of ground effect was observed as early as the Wright Brothers’ Wright Flyer I which...
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...Name: Harmony Ojehomon Topic: Wind blade Aerodynamic Content 1. Introduction 2. Calculation of the blade angle 3. Reynolds number 4. Testing the blade rotor in the wind turbine 5. Conclusion Introduction Wind power is one of the renewable technologies the world is counting on to provide sustainable and non-polluting power. The purpose report discusses how a prototype wind blade is designed, built and tested. The aim is to build a wind blade is built in terms of power extracted from the wind. Method F (resultant) D (drag) L (lift) Rw U The diagram above shows an aerofoil-section blade in a free air stream velocity U. Due to rotation of the turbine the blade velocity (at radius) is Rw. The angle of the aerofoil to the plane is θ. The air velocity relative to the blade is W, at an angle α to the blade: is called the angle of incidence. To ensure a good value of the lift coefficient Cl, α should be in the range 5o -12o. Calculation of the blade angle Take tip ratio λ=6.3 I choose 6.3 as the tip ratio because I am designing for 2 blade rotor. It needs a low drag coefficient on the blade to oppose the motion of the blade and so to detract from the wind turbine performance. Wind speed u= 9ms-1 The blade velocity Rw=54 The blade angle θ =? Tan θ = (u/Rw) θ =9.460 (approximate to whole number) =100 The angle of aerofoil θ=100. Since we already know the angle θ we need to calculate w which is a constant and since...
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...Distribution and Lift for an Airfoil Purpose The objectives of the experiment are to examine the surface pressure distribution and to compute the lift force acting on the airfoil. Test Design A body immersed in a flowing fluid is exposed to both pressure and viscous forces. The sum of the forces that acts normal to the free-stream direction is the lift, and the sum that acts parallel to the free-stream direction is the drag. The geometric and dynamic characteristics of airfoils are shown in Figure 1. This experiment is concerned with computation of the lift on a stationary airfoil mounted in the test section of a wind tunnel. We will consider only two-dimensional airfoils where tip and root effects are neglected. Because the velocity of the flow over the top of the airfoil is greater than the free-stream velocity, the pressure over the top is negative. This follows directly from the application of Bernoulli’s equation. Similarly the velocity along the underside of the airfoil is less than the free-stream velocity and the pressure there is positive. Hence, both the negative pressure over the top and the positive pressure along the bottom contribute to the lift. There are a variety of ways to measure lift. In this experiment, the lift force, L, on the airfoil will be determined by integration of the measured pressure distribution over the airfoil’s surface. Typical pressure distribution on an airfoil and its projection on the airfoil normal are shown in Figure...
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...How does a very low aspect ratio affect characteristics of an aircraft? HIgher aspect ratio is associated with a better lift to drag ratio and greater efficieny. Low A/R can work well with high speed aircraft because higher airspeed allows for greater lift at lower aspect ratios. Low A/R, which by definition means shorter wings with wider cord, can be built stronger due to lower bending moments and allow a greater roll rate due to lower rotational wing tip speed, lower rotational inertia and less inherent rollwise stability. Shorter wings (Lower AR) also makes the aircraft easier to fit into hangars, ramp spaces, etc. Aspect ratio (wing span / chord length) affects lift and drag. Gliders have a very high aspect ratio (high lift, low drag). The wind loading is very low (about 10 lbs / sq ft). The lighter the wing loading, the better the performance. Lift a bowling ball vs a balloon - which is easier for you. Why doesn't a 747 use a high aspect ratio wing? Because the wing loading would be tremendous unless the wing span was several hundred feet. It becomes a structural issue. So they have to compromise and use other means (flaps and slats) to reduce wing loading within the confines of the wing area. aspect ratio Aspect ratio is the wing span divided by the mean wing chord. An aircraft with a rectangular wing of area 12 m² might have a wing span of 8 m and wing chord of 1.5 m. In this case the aspect ratio is 5.33. If the span was 12 m and the chord 1 m then the aspect ratio...
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...AERODYNAMIC PRINCIPLES AND AIRCRAFT DESIGN ASSIGNMENT AERODYNAMIC PRINCIPLES AND AIRCRAFT DESIGN ASSIGNMENT INTRODUCTION It is really amazing how an aircraft is able to just take off from the ground and fly thousands of miles from place to place. How does it all work, do you ever wonder? Well obviously it’s not magic; it’s mainly because of aerodynamics. And when we talk about aerodynamics, it goes way beyond elevators, rudders, etc. Therefore we go to the depths of aerodynamics and its power to control a massive plane in the air. To be engineering in aerospace we need this extensive knowledge. In this report, you will learn about how an aircraft moves. The stability and control of the aircraft we also learn the factors influencing the static stability, the static margin and load factors. This report also gives us knowledge about the aircrafts control systems. | | | 1.1 | Motion of an aircraft | 4 | 1.2 | Degree of freedom | 4 | 2.1 | Static stability | 5 | 2.2 | Static margin | 5 | 2.3 | Dynamic stability | 6 | 3.1 | Stability in an aircraft | 6 | 3.2 | Longitudinal stability | 6 | 3.2.1 | Longitudinal dihedral | 7 | 3.3 | Lateral stability | 7 | 3.3.1 | Dihedral | 7 | 3.3.2 | Sweepback | 8 | 3.3.3 | Keel effect | 8 | 3.4. | Directional stability | 9 | 3.4.1 | sweepback | 9 | 4.1 | Load factor | 9 | 4.2 | Maneuver envelopes | 10 | 4.3 | Constraints on load factor | 10 | 4.4 | Load factors with respect to different...
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...Test Club Propeller A test club is used to test and break in reciprocating engines. [Figure 7-12] They are made to provide the correct amount of load on the engine during the test break-in period. The multi-blade design also provides extra cooling air flow during testing. Figure 7-12. Test club. Ground-Adjustable Propeller The ground-adjustable propeller operates as a fixed-pitch propeller. The pitch, or blade angle, can be changed only when the propeller is not turning. This is done by loosening the clamping mechanism that holds the blades in place. After the clamping mechanism has been tightened, the pitch of the blades cannot be changed in flight to meet variable flight requirements. The ground-adjustable propeller is not often used on present-day airplanes. Controllable-Pitch Propeller Figure 7-11. Fixed-pitch propeller. Fixed-pitch propellers are designed for best efficiency at one rotational and forward speed. They are designed to fit a set of conditions of both airplane and engine speeds and any change in these conditions reduces the efficiency of both the propeller and the engine. The fixed-pitch propeller is used on airplanes of low power, speed, range, or altitude. Many single-engine aircraft use fixed-pitch propellers and the advantages to these are less expense and their simple operation. This type of propeller does not require any control inputs from the pilot in flight. The controllable-pitch propeller permits a change of blade pitch, or angle, while the propeller...
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...ME2135 & ME2135E Fluid Mechanics II Semester 4 Session 2014/2015 Experiment II Flow over an Airfoil Venue: Fluid Mechanics Lab 2 WS2-01-47 (Ground Floor, Engineering Workshop 2) Tel: 6516-2231 2 January 2015 1 Table of Contents List of Figures 3 Nomenclature 3 1. Introduction 5 1.1 Background 5 1.2 Lift Generation 5 1.3 Objectives and Scope 5 2. Experimental Set-up 6 2.1 Wind Tunnel 6 2.2 Airfoil 6 2.3 Pressure Measurement 6 2.4 Velocity Measurement 6 6 3. Analysis 3.1 Free Stream Velocity 6 3.2 Pressure Coefficient 7 3.3 Force Coefficients 7 3.4 Trapezoidal Method 8 3.5 Thin Airfoil Theory 9 4. Procedure 9 4.1 Experiment 9 4.2 Tables 10 5. Results and Discussion 10 5.1 Results 10 5.2 Discussion 11 6. Conclusions and Recommendations 11 6.1 Conclusions 11 6.2 Recommendations 11 References 12 Figures 12 Tables 16 Appendix A 19 2 List of Figures Figure 1 a) Airfoil Terminology; b) Pressure Gradient across a Curved Streamline; c) Streamlines over an Airfoil 12 Figure 2 Airfoil in the Wing Tunnel 13 Figure 3 Schematic Diagram (Side View) of Pressure Measurement 13 Figure 4 Forces and Pressure on an Airfoil 14 Figure 5 Pressure Distribution around an Airfoil; at a=10° and Re=2.33x105 15 Figure 6 Area between Two Curves using Trapezoidal Method ...
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...1. Blade Design: The design of the blade does not just depend on the stress analysis; several other factors play significant roles as well. The leading edge is thicker than the trailing edge for a streamlined Flow. Furthermore, the blade should be as thin as possible to improve cavitation Characteristics; it is thicker near the flange becoming thinner and thinner towards the tip. In Addition, the blade has to be distorted on the basis of the tangential velocity. Blade design is the most complex thing in Kaplan turbine. It consists of six steps. 1. Velocity triangle is evaluated at the leading and Trailing edge of the blade. 2. Angle of distortion of the chord lengths (β∞). 3. Lift Coefficients. 4. Chord length to Spacing (L/t) ratio. 5. Drag Coefficient. 6. Profile. 2.1. Velocity Triangle: U U As shown in the figure different types of velocities occur as the fluid flows from the blades of this turbine. Thorough understanding of the velocity triangle (fig 1. 1) is necessary for a good design. Figure 1.1 Figure 1.1 β∞ β∞ Wu Wu Cu Cu Wm Wm Cm Cm Blade Tangential Velocity ………. (1.1) Tangential Flow velocity ……………… (1.2) Relative Tangential Velocity……………. (1.3) Relative Axial Velocity…………………… (1.4) Where, U = blade Tangential velocity [m/s] Wm= Axial Component relative velocity [m/s]. Cm = Axial Component flow Velocity [m/s]. Cu= Tangential Component flow velocity [m/s]. Wu= Tangential Component relative velocity [m/s]...
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...Class #1 Licensing Requirements, Airframes & Theory of Flight Introduction/Theory of Flight LICENCING REQUIREMENTS Student Pilot Permit Age: _______ Medical Category: I, III or IV Written Test (PSTAR) _______% Recreational Pilot Permit Age: _______ Medical Category: I, III or IV Written Test _______% (Must have valid Medical and 10 hours flight time) Training: 25 hours total time 15 hours dual (2 hours dual cross country with two 30 min legs) 5 hours PIC Flight Test:________ % Private Pilot Licence Age: _______ Medical Category: __________ Written Test _______% (Must have valid Medical, ground school time and 10 hours flight time) Training: 45 hours total time 15 hours dual (3 hours dual cross country, 5 hours instrument training). 12 hours PIC (5 hours PIC cross country, including a 150 nm route with 2 stops) Flight Test: ______ % Night Rating Must hold a Private Pilot Licence Training: ______ hours of flight training consisting of: 5 more hours of instrument training 10 hours night (5 dual 2 hours cross country, 5 Solo, 10 takeoffs and landings) No Flight Test or Written Test VFR Over-The- Top (VFR OTT) Must hold a Private Pilot Licence Training: Minimum of 15 hours dual instrument time Multi-Engine Rating Training: No minimum hours required Flight Test Required Instrument Rating Group 1: _______; Group 2 ___________ Written and flight test required Training: 40 hours instrument time required (1 dual cross...
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...SPIN AWARENESS AND AVOIDANCE Objective To teach the student the avoidance and proper recovery from spins. Elements • Uncoordinated stalls • Aerodynamics of a spin • Recovery procedure Schedule Discussion 0:30 Equipment Model airplane Instructor Actions Discuss what is a spin (an aggravated stall that results in autorotation). Autorotation results from unequal angles of attack on the wings. The key is aggravated (i.e. uncoordinated). Draw or show the corkscrew/helical flight path of a spin. The difference between a spin and a steep spiral: spin—airspeed low, wings stalled; spiral—airspeed increasing, not stalled. Discuss the aerodynamics of a spin. Draw a wing in straight-and-level flight and in slow flight. Use actual angles of attack. Typical light aircraft wings stall at 18-22º. How can you enter a spin? Wing exceeds critical angle of attack with yaw acting on aircraft (uncoordinated). That is, a stall when in a slipping or skidding turn. Danger of base to final turn—cross controlled stall leading to spin. The high wing has the greatest lift due to the greater airspeed, and overall less drag and lower angle of attack. The low wing has the least lift (due to lower airspeed) and greatest parasitic drag due to its higher angle of attack. Center of gravity affects the spin characteristics. An aft CG makes spin recovery more difficult. The worst case is the aircraft may enter into a flat spin if CG is too far back, making recovery impossible. Center...
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...National University of Singapore Bachelor of Technology Programme ME2135E Fluid Mechanics II (Lab Report) Flow Over An Airfoil Group: 4B Experiment Date: 13.02.2015 1 Experiment II: Flow Over an Airfoil 1. Introduction An airfoil is a two dimensional cross-section of an airplane wing. It may be thought of as a wing of infinite span with constant cross-sectional shape. With a forward speed, wings can generate a lift force which enables the airplane to stay airborne. Airfoil shapes are designed to provide high lift values at low drags, for given flight conditions. Airfoil studies are not only relevant for airplanes, but also applicable to wings on F1 cars and blades of a helicopter, propeller hydrofoil, and wind turbine. A typical subsonic airfoil has a streamline profile with a fairly rounded nose (leading edge) and a sharp tail (trailing edge). A chord line is a straight line joining the leading to trailing edges, the length of which is called the chord c. the acute angle between the free stream velocity direction and the chord line is called the angle of attached a 2. Objectives and Scope The objectives of this experiment were to investigate the pressure distribution around the airfoil and to calculate the lift and drag forces. The experiment was conducted at a specified angle of incidence relative to the wind direction and at a specified wind speed. 3. Experimental Set Up. 1) Wind Tunnel The air flow was generated by the blower of a subsonic...
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...The Egg Drop project consisted of a few different materials that lessened the egg’s force of impact on the earth. The materials used were: two toilet paper rolls, nine and a half straws, and a half piece of printer paper. Other materials used were: very strong glue and masking tape to hold the contraption together. The egg never touched the ground, which lessened the force on it. Instead of the egg receiving the maximum force of the cement, the materials around it did. The outside materials were very important for this project to be successful because they were much stronger, and provided a lot more support than the egg alone. The main feature of the container that lessened the force when it came in contact with the earth...
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