...constant. It always acts straight down toward the center of the earth (Four Forces on an airplane 1). Lift is the upward force produced by the effect of airflow as it passes over and under the wings. It helps maintain the airplane in flight. Weight opposes lift, it is caused by the downward pull of gravity. Thrust is the forward force which propels the airplane through the air. It varies with the amount of engine power being used. Opposing thrust is drag, which is a backward force that decreases the speed of the airplane (What is Thrust 1). Lift is the key aerodynamic force. It is the force that opposes weight. In straight and level flight when weight and lift are equivalent, an airplane is said to be in a state of equilibrium. If the other aerodynamic factors remain constant, then that airplane neither gains nor loses altitude. Movement of air on the airplane, particularly the wing, is necessary in order for the aerodynamic force of lift to become effective. During flight, however, pressures on the upper and lower surfaces of the wing are not the equal. Although several factors contribute to this difference, the shape of the wing plays an important role. The wing is designed to divide the airflow into areas of high pressure below the wing and areas of comparatively lower pressure above the wing (Four Forces on an airplane). This pressure differential, which is created by movement of air about the wing, is the primary source of lift. The weight of the airplane is not a constant...
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...Aerodynamics in Cycling Aerodynamics has become enormously important in bicycle road racing, even more than weight. Bikes are so light these days that it is not unusual to add weights just to get them up to the required minimum weights. Wind tunnel testing is used extensively both in manufacturing and training. Manufacturers test bikes and components in order to reduce drag. One trend in recent years that I find counter intuitive is wider wheels. Newer rims sometimes have a cross section similar to an airfoil, wide in the front and tapering towards the back, or inside of the wheel. They have also added dimples similar to golf ball dimples. In general, most tube cross sections are now being stretched out to an airfoil like shape. Each little thing does not change much, but put together they can make a huge impact on the effort the rider has to put out in the end. A team manager needs to know how to balance many factors such as aerodynamics, weight, cooling, and strength amongst others. As an example for a race with many steep climbs, aerodynamics is less important than weight and cooling for the rider. Maybe a helmet with many vents and high drag is in order so the rider will not over heat. Light but high drag wheels are also ok. On the other hand, it is opposite during a flat time trial, when the rider rides all alone without any drafting behind other riders. In this situation, everything must be low drag, bike, wheels, suit, helmet...
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...When you hear the word aerodynamics, the first thing that comes to mind is airplanes and pilots. There are other applications that apply. For instance, the passing of a football. A football that is thrown into the air has inertia. This is the tendency of an object in motion to remain in motion. But because of gravity the ball is pulled down and resistance that slows the ball down. A quarterback through the motions of his and body, must balance the forward momentum that he gives the ball, fighting gravity and air resistance that pulls and slows it down. Aerodynamics is involved during passing because of the spin that is applied. The better the spin the straighter and further the ball will travel. This is accomplished by the quarterback throwing the football over handed or a sidearm motion to giving it the spin required. The spin causes the ball’s angular momentum points in the direction of its long axis. At same time due to air drag, torque is pointing perpendicular to the angular momentum. The ball travels on a semi-parabolic curve and wind torque produces a small change in the ball’s angular momentum. This allows the ball to continue to turn around its trajectory. Therefore spinning stabilizes the football through angular momentum and torque. Throwing in this manner orientates the ball giving it the smallest possible cross sectional area against the oncoming air; this causes the least amount of aerodynamic drag. This is important for quarterbacks as while as managers...
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...2nd Flow Control Conference 28 Jun - 1 Jul 2004 / Portland, Oregon AIAA-2004-2319 Aerodynamic Performance of Biological Airfoils Abel Vargas* and Rajat Mittal† The George Washington University, Washington, D.C., 20052 Experimental studies on static, non-flapping dragonfly wings have shown favorable aerodynamic performance at low Reynolds number (Re ≤ 10,000). High lift is hypothesized to arise from the dragonfly’s pleated wing structure. A numerical study of flow past a modeled dragonfly wing section as well as its comparison to a corresponding profiled airfoil and a flat plate were conducted at Re = 10,000. The main focus of the current investigation was to determine the primary flow features and mechanisms that are responsible for the enhanced performance of these biological wing sections at these relatively low Reynolds numbers. A time-accurate Cartesian grid based Navier-Stokes immersed boundary solver was utilized in the current study. The numerical results indicate that the pleated airfoil at a zero degree angle-of-attack generates the least drag despite its unconventional shape. Additionally, a higher transitory lift is produced by the pleated airfoil at a five degree angleof-attack when compared to the profiled airfoil. Nomenclature c CD CDs CDp CL CLs CLp P Re τ t t* ui = = = = = = = = = = = = = = = = chord length drag coefficient shear drag coefficient pressure drag coefficient lift coefficient shear lift coefficient pressure lift coefficient Pressure Reynolds...
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...Aerodynamics of Supersonic Aircraft Name: Institution: Aerodynamics of Supersonic Aircraft The world over the past three decades has experienced manned aircraft travelling at supersonic speeds. Supersonic aircraft exhibit a much higher propulsion system as opposed to the previous aircraft, therefore, they are more efficient (Winchester, 2008). In this respect, the designer cannot allow this efficiency to drop below the theoretical optimum in spite of the increased complexity and weight. In addition, these types of aircraft have a greater interaction between the airframe and the engine than their previous counterparts. Apparently, it is no longer possible to rationalize between optimizing a propulsion package to a separately optimized airframe (Torenbeek, 2013). The two parts work in tandem and thus they should be fully integrated into all aspects by the designer. Supersonic aircraft refer to those planes that travel at a relatively faster speed compared to that of sound (Gunston, 2008). These types of planes were developed in the mid-twentieth century and had been extensively deployed purely for research and military works. Two types of airlines, namely the Concorde and the A-11/SR-71 aircraft mark the development of a novel class of planes designed purposely for supersonic operation. The most typical example of a supersonic aircraft is the jet fighter, however, it does not travel at a speed that exceeds that of sound. Other examples include the Conair B-58 and XB-70 (Mindling...
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...Aerodynamics and Aircraft Performance Characteristics of High-speed Flight Embry-Riddle Aeronautical University From the beginning of the age of manned flight, aviators and engineers have continuously sought to increase the performance envelope. Many parameters for defining aircraft performance exist, but here I’d like to focus on going fast. Since I was a child I’ve been fascinated with military aircraft and the pursuit of speed. From the Bell X-1 to the famed SR-71 Blackbird and beyond, high-speed flight has been a chase toward an ever increasing limit. Several factors contribute to the aerodynamics of supersonic flight and many limitations apply as the envelope is pushed. I will focus the perspective of this paper on design characteristics, engine technology, and atmospheric considerations and take a peek into the future of hypersonic flight. In order to discuss the design characteristics of high-speed aircraft, a definition for the speed regimes must be given. Supersonic flight is typically defined as greater than Mach 1 but less than Mach 3. “High” Supersonic flight is a narrow band of operation from Mach 3 to 5 and hypersonic flight is in excess of Mach 5 (Benson, 2013). Shape technology and wing design are the primary areas of concern in setting out to build an aircraft capable of supersonic speeds. If airflow velocities reach sonic speeds at some location on an aircraft further acceleration results in the onset of...
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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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...Research on Aerodynamic Drag Reduction by Vortex Generators Masaru KOIKE* Tsunehisa NAGAYOSHI* Naoki HAMAMOTO* Abstract One of the main causes of aerodynamic drag for sedan vehicles is the separation of flow near the vehicle’s rear end. To delay flow separation, bump-shaped vortex generators are tested for application to the roof end of a sedan. Commonly used on aircraft to prevent flow separation, vortex generators themselves create drag, but they also reduce drag by preventing flow separation at downstream. The overall effect of vortex generators can be calculated by totaling the positive and negative effects. Since this effect depends on the shape and size of vortex generators, those on the vehicle roof are optimized. This paper presents the optimization result, the effect of vortex generators in the flow field and the mechanism by which these effects take place. Key words: Body, Aerodynamics, Aerodynamic Devices, Flow Visualization, Computational Fluid Dynamics (CFD) 1. Introduction To save energy and to protect the global environment, fuel consumption reduction is primary concern of automotive development. In vehicle body development, reduction of drag is essential for improving fuel consumption and driving performance, and if an aerodynamically refined body is also aesthetically attractive, it will contribute much to increase the vehicle’s appeal to potential customers. However, as the passenger car must have enough capacity to accommodate passengers and baggage...
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...In late 1903, a pair of brothers built and flew the very first practical fixed-wing aircraft in the small town of Kill Devil Hills, North Carolina. Though the Wright brothers were not the first to experiment with flying machines, they were the first to design an aircraft that had three-axis control by which a pilot could control the pitch, roll, and yaw. Today’s aircraft are much more advanced, but the concept has remained unchanged for almost 110 years. The website listed above provides an outline of the basic parts, control surfaces, and other components of a typical aircraft. It also contains pictures and information detailing where each component is located and what each component achieves during flight. The components that I found interesting were the same components the Wright brothers used to control the flight of their first aircraft. Those components are the elevator, the rudder, and the aileron. The elevator is the component that controls the pitch of the aircraft. There are two elevators located in the rear of the aircraft on each side of the horizontal stabilizer. By moving the elevators up or down, a pilot can change the amount of down force applied to the tail, thus moving the aircraft nose up or down. The rudder is the component that controls the yaw of the aircraft. The rudder is also located in the rear of the aircraft on the aft end of the vertical stabilizer. By moving the rudder left or right, the side force produced by the vertical stabilizer changes...
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...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 flew in the presence of ground effect. During World War II, war...
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...Activity 2.6 – Aerodynamics on Arrow Arrow would be my aerodynamic example. Its has a very long history, we can start from the stone age till present. Arrow from back then was made by bones or stones for the head (projectile point) and wood or bamboo for the body (shaft). Now, we have tungsten or stainless steel for the projectile point and aluminum or carbon fibre reinforced plastic or composite for the shaft. The evolution of the entire piece of arrow had changed so much, etc from the head, body to the end, every part of it had streamlined with the science of aerodynamic, to attain the expectations of being fast, far and accurate. The aerodynamic of it would be the whole piece, projectile point to cut thru the wind, aerofoil body to assist to travel further, last but not the least is the fletching. It at the end of the arrow, it provide a small amount of drag to stabilize the flight of the arrow. They are designed to keep the arrow pointed in the direction of travel by strongly damping down any tendency to pitch or yaw. The aspect of management in it, you have to be flexible and upgrade yourself to stay the fittest to stay in the market. When the senior management changes strategic planning to suit environment changes, middle management and supervisory level must also change to suit the plan. Look at it as senior management being the fletching setting the direction, middle management being the shaft ensuring the plan go on course and supervisory level being the...
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...to the 1870’s. Scientists realized it didn’t matter if an object was stationary and air was blown was over the object or if the object was moving through the air. The resultant forces over the object would be the same. The idea of blowing air over an object and determining the forces lead to the invention of wind tunnel. As the name suggests, a wind-tunnel is a cylindrical tunnel in which air is blown from one side by a huge fan at high speeds. The middle part of the tunnel is called as throat. It is the place where the test model is placed. Various sensors are attached to the test model and the data is collected in the room near it. The data collected issued to reduce the aerodynamic drag and minimize fuel consumption and also increase the speed of the cars, trucks, planes, etc. also aerodynamic properties like lift, drag, forces, moments are measured with the use of wind-tunnel. In wind-tunnel air is blown over the test model which is kept stationary at the throat. This will produce the same effect as it would be produced if the vehicle is moving at high speeds on a road. For more accurate results the tunnel is sometimes equipped with rolling road to prevent the boundary layer forming on the floor which may affect the test results. * What are wind tunnels? Just as its name suggests, a wind tunnel is a tube or tunnel that has man-made windblown through it at a certain speed. Scientists and engineers put a model of an airplane in the tunnel and then study the...
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...aircraft's direction in flight. (4).Mass The weight of the aircraft is the common factor that links all aspects of aircraft design such as aerodynamics, structure, and propulsion together. An aircraft's weight is derived from various factors such as empty weight, payload, useful load,. (5).Structure The aircraft structure focuses not only on strength, stiffness, durability, fracture toughness, stability, but als o on fail-safety corrosiion resistance, maintainability and ease of manufacturing. The structure must be able to withstand the stresses caused by cabins pressure, if fitted, turbulence and engine or rotor vibrations. Desing process and desingn simulation The design of any aircraft starts out in three phases The first design step, involves sketching a variety of possible aircraft configurations that required, engine size and type are all determined at this stage. Constraints to design like thosementioned above are all taken into account at this stage as well. The fi nal product is a conceptual layout of the aircraft configuration on paper or computer screen, to be reviewed by engineers and other designers. Primary design . In this phase, wind tunnels testing and computational fluid dynamic calculations of the flow field around the aircraft are done. Major structural and control analysis is also carried out in this phase. Aerodynamic defects and structural instability es if any are corrected and then the final design is dra wn and finalized. Then after the finalization...
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...DELL’AUTOVEICOLO (AUTOMOTIVE ENGINEERING) Thesis for degree of Bachelor of Science Electric City Car – Energy consumption analysis Supervisor: Prof. Giuliano Cozzari, Prof. Andrea Festini Applicant: Zheng Hang 1. Introduction 1.1. 1.2. 1.3. General introduction about EV and the team project Speed and acceleration, all about an EV Basic concept in calculation 2. Energy consumption calculation in design phase 2.1. Weight and distribution effect 2.1.1. Weight and climbing 2.1.2. Weight and speed 2.1.3. Weight affect range, Balance and other important facts 2.2. Aerodynamic effect 2.2.1. Define of aerodynamic drag force 2.2.2. Other aerodynamic contributes 2.2.3. Effective of frontal area and coefficient of drag 2.3. Rolling resistance 2.3.1. Definition of rolling resistance 2.3.2. Combined analysis of aerodynamic drag and rolling resistance 2.3.3. Maximum power that can be transferred by the tires to the road 2.4. Transmission efficiency analysis 2.4.1. Structures about the transmission system available 2.4.2. Efficiency of the transmission system 3. Energy consumption calculation of EV 1 3.1. Calculation methodology overview and Target specification of our EV 3.2. Calculation and evaluation of the energy consumption 3.2.1. Required and available power 3.2.2. Motor output and acceleration 3.2.3. Acceleration time evaluation of our EV 3.3. Conclusion 4. Influence on energy output 4.1. Mileage...
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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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