This document provides information about measuring the lift and drag of an airfoil. It discusses the basic forces on an airfoil, including lift and drag. It describes how pressure distributions over the airfoil surface can be measured using pressure taps, and how the pressure measurements can be used to calculate lift and drag coefficients. The document outlines the objectives, procedures, and expected results for an experiment using a wind tunnel to acquire pressure distributions on a NACA 2415 airfoil at varying angles of attack and air speeds.
The document discusses the concepts of stability, maneuverability, and controllability as they relate to aircraft design. It states that stability causes an aircraft to return to steady flight after a disturbance, maneuverability allows the pilot to move the aircraft easily about its axes, and controllability is the ability to respond to pilot inputs. However, increasing one of these characteristics typically decreases another, so aircraft designs involve compromises. The document then examines longitudinal, lateral, and directional stability in more detail.
Fatigue life estimation of rear fuselage structure of an aircrafteSAT Journals
This document summarizes a study on estimating the fatigue life of the rear fuselage structure of an aircraft. The researchers created a finite element model of the rear fuselage structure in CATIA and analyzed it in MSC.PATRAN and MSC.NASTRAN to identify high stress regions. They found the maximum stress locations were at cut-out corners and rivet holes in the skin. A local model with finer meshing around the cargo door cut-out was also analyzed. Fatigue life was then estimated using Miner's rule and an S-N curve, accounting for factors like surface roughness and reliability. Damage was accumulated over the expected load cycles to predict fatigue life until crack initiation.
This document discusses aeroelastic flutter analysis. It begins by defining aeroelasticity and describing different aeroelastic phenomena including divergence, flutter, limit cycle oscillations, and vortex shedding. It then discusses Collar's triangle of forces and Garrick's aerothermoelastic tetrahedron models. The document defines flutter as a dangerous vibration phenomenon in structures subjected to aerodynamic forces. It provides examples of different types of flutter and describes predicting flutter in turbomachines. Finally, it summarizes a case study on material mode flutter analysis of laminated curved panels.
Gliders are aircraft that are supported in flight through the dynamic reaction of air against their lifting surfaces without an engine. Some gliders have small engines to extend flight or for launching. The Wright Brothers spent years experimenting with gliders to develop efficient airfoils and flight control before attempting powered flight. Modern gliders include sailplanes for recreation, hang gliders that are foot-launched, and almost ready-to-fly models that require minor assembly. Gliders find lift through thermals or slope lift and pilots circle to remain in rising air. Winches are commonly used to launch larger sailplanes a few hundred feet and electric motors now assist some gliders. Efficiency is measured by glide ratio and half the drag
Cours PPL(A) : Les instruments et le groupe motopropulseurSofteam agency
Cours sur les instruments (tableau de bord, circuit anémométrique, circuit de dépression, gyroscope, anémomètre, altimètre, variomètre, compas, conservateur de cap, horizon artificiel, bille, indicateur de virage, EFIS) et le groupe motopropulseur (moteur à piston, carburateur, injection, allumage, magnétos, ...) dans le cadre de la formation PPL(A) ou LAPL(A).
Attention, ce support de formation peut contenir des erreurs éventuelles. Je vous recommande de vous rapprocher de votre FI attitré pour vos cours théoriques.
Certaines images et photographies sont issues de captures écrans depuis Google. Certains contenus sont issus du Manuel du pilote privé et de sources Internet tels que l'avionnaire.
This document provides an overview of aircraft landing gear systems. It describes three common types of landing gear: tricycle gear, taildragger gear, and ski gear. It then discusses key components of landing gear systems like nose wheel steering, shimmy damping systems, and safety systems. Nose wheel steering uses hydraulic power to turn the nose wheel. Shimmy damping systems like piston, vane, and steer types control unwanted vibration. Safety systems include mechanical downlocks, safety switches, and ground locks to prevent accidental gear retraction.
The document discusses the concepts of stability, maneuverability, and controllability as they relate to aircraft design. It states that stability causes an aircraft to return to steady flight after a disturbance, maneuverability allows the pilot to move the aircraft easily about its axes, and controllability is the ability to respond to pilot inputs. However, increasing one of these characteristics typically decreases another, so aircraft designs involve compromises. The document then examines longitudinal, lateral, and directional stability in more detail.
Fatigue life estimation of rear fuselage structure of an aircrafteSAT Journals
This document summarizes a study on estimating the fatigue life of the rear fuselage structure of an aircraft. The researchers created a finite element model of the rear fuselage structure in CATIA and analyzed it in MSC.PATRAN and MSC.NASTRAN to identify high stress regions. They found the maximum stress locations were at cut-out corners and rivet holes in the skin. A local model with finer meshing around the cargo door cut-out was also analyzed. Fatigue life was then estimated using Miner's rule and an S-N curve, accounting for factors like surface roughness and reliability. Damage was accumulated over the expected load cycles to predict fatigue life until crack initiation.
This document discusses aeroelastic flutter analysis. It begins by defining aeroelasticity and describing different aeroelastic phenomena including divergence, flutter, limit cycle oscillations, and vortex shedding. It then discusses Collar's triangle of forces and Garrick's aerothermoelastic tetrahedron models. The document defines flutter as a dangerous vibration phenomenon in structures subjected to aerodynamic forces. It provides examples of different types of flutter and describes predicting flutter in turbomachines. Finally, it summarizes a case study on material mode flutter analysis of laminated curved panels.
Gliders are aircraft that are supported in flight through the dynamic reaction of air against their lifting surfaces without an engine. Some gliders have small engines to extend flight or for launching. The Wright Brothers spent years experimenting with gliders to develop efficient airfoils and flight control before attempting powered flight. Modern gliders include sailplanes for recreation, hang gliders that are foot-launched, and almost ready-to-fly models that require minor assembly. Gliders find lift through thermals or slope lift and pilots circle to remain in rising air. Winches are commonly used to launch larger sailplanes a few hundred feet and electric motors now assist some gliders. Efficiency is measured by glide ratio and half the drag
Cours PPL(A) : Les instruments et le groupe motopropulseurSofteam agency
Cours sur les instruments (tableau de bord, circuit anémométrique, circuit de dépression, gyroscope, anémomètre, altimètre, variomètre, compas, conservateur de cap, horizon artificiel, bille, indicateur de virage, EFIS) et le groupe motopropulseur (moteur à piston, carburateur, injection, allumage, magnétos, ...) dans le cadre de la formation PPL(A) ou LAPL(A).
Attention, ce support de formation peut contenir des erreurs éventuelles. Je vous recommande de vous rapprocher de votre FI attitré pour vos cours théoriques.
Certaines images et photographies sont issues de captures écrans depuis Google. Certains contenus sont issus du Manuel du pilote privé et de sources Internet tels que l'avionnaire.
This document provides an overview of aircraft landing gear systems. It describes three common types of landing gear: tricycle gear, taildragger gear, and ski gear. It then discusses key components of landing gear systems like nose wheel steering, shimmy damping systems, and safety systems. Nose wheel steering uses hydraulic power to turn the nose wheel. Shimmy damping systems like piston, vane, and steer types control unwanted vibration. Safety systems include mechanical downlocks, safety switches, and ground locks to prevent accidental gear retraction.
Angle of attack | Flight Mechanics | GATE AerospaceAge of Aerospace
This document provides an overview of flight mechanics topics including angle of attack. It discusses the angle of attack (AOA) as the angle between the relative wind and chord line of an airfoil. Greater AOA results in greater lift but also greater drag. Higher AOA variation can cause stall from loss of lift. It recommends visualizing AOA effects using NASA's FoilSim tool. The document also outlines core topics like aircraft configurations, flight instruments, aerodynamic forces, airplane performance, stability, and dynamic stability to be covered.
Formation FI(A) : La météo (Exposé AéroPyrénées)Softeam agency
Exposé sur la météo, réalisé dans le cadre de ma formation FI (Flight Instructor) avion chez Aéro Pyrénées à Toussus (LFPN).
Attention, ce support de formation peut contenir des erreurs éventuelles. Je vous recommande de vous rapprocher de votre FI attitré pour vos cours théoriques.
Certaines images et photographies sont issues de captures écrans depuis Google.
Design and analysis of bodyworks of a formula style racecareSAT Journals
Abstract: The aim was to develop a body of the racecar with the proper studies and analyses, taking into account several factors, to present an optimum structure as a final result. These factors include, but are not limited to, weight, cost, drag resistance, functionality and aesthetics. The expected product is to not just be appealing to the eye but also increase the performance of the vehicle. Additional objectives include being able to accommodate the budget while maintaining a highly competitive level to perform well in on the race track. The new design will reduce the weight of the prototype and as well as the air drag, taking into consideration the ground effects desired to be implemented in the vehicle as a crucial factor. Moreover, the new body will be easier to dismantle reducing the service time. Keywords: drag resistance, aesthetics, performance, weight, cost.
This document discusses vertical take-off and landing (VTOL) aircraft. It defines VTOL aircraft as those that can take off, hover, and land vertically. There are two main types of VTOL technology: rotorcraft like helicopters, cyclocopters, and gyrodynes that use rotating wings to generate lift; and powered-lift aircraft like tiltrotors, tiltwings, and tail-sitters that can direct engine thrust vertically for takeoff and landing. The document outlines the key characteristics and advantages of various VTOL aircraft types and concludes by discussing future developments including electric VTOL aircraft and flying taxi services.
This document outlines the course objectives and content for Aerodynamics 301A taught at Cairo University's Faculty of Engineering. The course aims to teach students: 1) how to predict aerodynamic forces on aircraft components and whole aircraft; 2) how to determine air properties moving internally through engines; and 3) how to apply various aerodynamic principles to different applications. The course covers topics such as the governing equations of fluid motion, potential flow theory, and finite wing theory.
The document discusses vortex theory and Prandtl's lifting-line theory for analyzing the aerodynamics of finite wings. It introduces key concepts like downwash, trailing vortices, Helmholtz's vortex theorems, and the Biot-Savart law. The lifting-line theory models the wing as a bound vortex filament with varying circulation strength. This allows determining the induced downwash and angle of attack distributions. Prandtl's fundamental equation relates the circulation distribution to the wing geometry and twist. The lifting-line theory provides insights into the relationship between wing shape and lift distribution.
ME438 Aerodynamics is offered by Dr. Bilal Siddiqui to senior mechanical engineering undergraduates at DHA Suffa University. This lecture set is about prediction of lift on thin cambered airfoils.
This document provides an overview of aircraft landing gear systems. It describes the main components, including the types of landing gear arrangements (tail wheel, tandem, tricycle), construction details, alignment and retraction mechanisms, nose wheel steering, braking systems, tires, and antiskid systems. The purpose of landing gear is to support the aircraft during landing and taxiing. Retractable gear stows in the fuselage or wings to reduce drag while flying. Nose wheel steering and braking systems provide directional control on the ground. Aircraft tires must withstand high loads and provide traction for takeoff and landing. Antiskid systems help maintain braking effectiveness.
aircraft static and dynamic stability,longitudinal and lateralJini Raj
This document discusses the theory of flight stability. It defines three types of stability - dynamic, static, and inherent stability. It then discusses the three axes of stability in more detail: longitudinal stability around the lateral axis affected by horizontal stabilizer and center of gravity position, lateral stability around the longitudinal axis created through dihedral, keel effect, and sweepback wings, and directional stability around the vertical axis provided by the vertical tail surface.
Basic Info regarding making a RC aeroplaneZubair Ahmed
The document provides information on the control surfaces and aerodynamic components of an aircraft. It discusses that elevators control pitch, ailerons control roll, and the rudder controls yaw. It also mentions vertical and horizontal stabilizers provide stability and prevent pitching and yawing motions. The document further provides details on requirements, wing design and construction, airfoils, servos, engines, batteries, and tips for stability.
This document provides an overview of aeroelasticity, including its history, classifications, and precautions. It discusses how aeroelasticity studies the interaction between inertial, structural and aerodynamic forces. The document outlines the necessity of studying aeroelasticity effects for rotor design, wind energy, and to understand catastrophic failures. It then describes different types of static and dynamic aeroelasticity like divergence, control reversal, flutter, buffeting, and transonic phenomena. Precautions like testing and analysis are discussed.
This document provides an overview of aircraft wings, including their:
- Historical development from ancient kites to the Wright brothers' fixed-wing aircraft.
- Construction, with internal structures like ribs, spars, stringers, and skin covering the framework. Wings also contain fuel tanks, flaps, and other devices.
- Functions, as wings generate lift through Bernoulli's principle and critical angle of attack. Wing design factors like aspect ratio and camber also affect lift.
- Types based on position (fixed or movable) and structure (cantilever or strut-braced). Stability devices like ailerons and flaps are also described.
- Unconventional designs that
Support de cours pour la formation à la variante EFIS (Electronic Flight Instruments System) pour Glass Cockpit Garmin G1000.
Attention, ce support de formation peut contenir des erreurs éventuelles. Je vous recommande de vous rapprocher de votre FI attitré pour vos cours théoriques.
Certaines images et photographies sont issues de captures écrans depuis Google. Certains contenus sont issus de la documentation officielle de Garmin.
1) O documento descreve os principais componentes e classificações de helicópteros, incluindo os rotores, grupo motopropulsor, estrutura e tipos de rotores.
2) Os três tipos principais de giroaviões são o helicóptero, o autogiro e o giródino. O helicóptero pode voar verticalmente e em voo estacionário enquanto os outros não.
3) Os helicópteros são classificados de acordo com a configuração dos rotores, como rotor simples, rotor co-axial e rotor lado a lado.
This document discusses aircraft structural design limits and flight envelopes. It explains that flight envelopes graphically show the speed and load factor limits an aircraft can withstand based on factors like stall speed and maneuvering capabilities. The curves account for factors like altitude and critical Mach number. Load factors in the flight envelope are determined based on expected maneuvering loads and gust loads, with statistical analysis used to estimate extreme loads the aircraft may encounter over its operational life. Structural design limits like limit load, proof load, and ultimate load are set to ensure the aircraft can withstand expected loads with safety margins.
The document discusses solar powered aircrafts. It provides an introduction to solar powered planes, explaining that they use solar panels on their wings to gather solar energy and recharge batteries that power propellers, allowing the planes to stay airborne for up to 26 hours. It then covers various topics related to solar aircrafts, including their concept and working, evolution over time, types that exist, challenges they face, and specifics of the Solar Impulse aircraft including its specifications and flight achievements. Advantages are renewable energy source and lack of emissions, while disadvantages include inefficiency of solar panels and reliance on sunlight.
The document discusses various techniques for reducing vibration in helicopters, including passive, active, and semi-active methods. Passive techniques like tuned mass absorbers and blade design optimization provide moderate vibration reduction but with a significant weight penalty. Active concepts like higher harmonic control and individual blade control generate unsteady loads to cancel vibrations, but require external power. Semi-active systems modify structural properties using small amounts of power. The most successful current method is active control of structural response, which places actuators throughout an airframe to reduce vibrations measured by sensors.
Morphing Aircraft Technology – New Shapes for Aircraft Wing DesignMani5436
Morphing aircraft are multi-role aircraft that change their external shape substantially to adapt to a changing mission environment during flight.
Morphing poses several unique challenges when the wing loading is high. Very flexible materials are the designer’s first choice because they are easily reshaped.
he current use of multiple aerodynamic devices (such as flaps and slats) represents a simplification of the general idea behind morphing. Traditional control systems (with fixed geometry and/or location) give high aerodynamic performance over a fixed range and for a limited set of flight conditions.
This document discusses various aerodynamic characteristics of airfoils and wings. It describes how aerodynamic forces are generated by pressure and shear stress distributions on surfaces. It also defines key terms like lift, drag, angle of attack, center of pressure, aerodynamic center. Methods to increase lift or reduce drag like high-lift devices, supercritical airfoils, and winglets are explained. Different types of airfoils and their characteristics are also summarized.
Morphing of Aircraft Wings
This document discusses morphing technology for aircraft wings. Morphing allows wings to change shape to better match flight conditions. It can improve performance, efficiency, and adaptability. Wing morphing technologies include folding, sweeping, extending wings, and changing camber. This allows control of wing area, aspect ratio, and sweep angle. Shape memory alloys are used for actuation components. Advantages of morphing wings include improved performance, control, stealth, reduced drag and weight. Challenges remain in developing morphing wing technologies that can withstand flight conditions.
A Good Effect of Airfoil Design While Keeping Angle of Attack by 6 Degreepaperpublications3
Abstract: Airfoil is a shape of wing or blade of (a propeller, rotor or turbine) by which a fluid generates an aerodynamic force. The component of this force perpendicular to the direction of its speed is called lift force and the component parallel to its speed is called drag forces. Here we see that if we set the angle of attack by 6 degree in fluid NACA0012 we found the aerodynamic forces with suitable positive result our research is totally based on iterations method and based on the help of cfd software.
The document discusses aerodynamic analysis of the NACA 0012 airfoil using computational fluid dynamics (CFD). CFD simulations were performed in ANSYS Fluent to analyze flow behavior and calculate aerodynamic forces at varying angles of attack from 0 to 20 degrees. The results obtained from the CFD analysis matched theoretical predictions and experimental data. Key parameters like pressure and velocity distributions, lift and drag coefficients, and lift to drag ratios were evaluated to understand airfoil performance.
Angle of attack | Flight Mechanics | GATE AerospaceAge of Aerospace
This document provides an overview of flight mechanics topics including angle of attack. It discusses the angle of attack (AOA) as the angle between the relative wind and chord line of an airfoil. Greater AOA results in greater lift but also greater drag. Higher AOA variation can cause stall from loss of lift. It recommends visualizing AOA effects using NASA's FoilSim tool. The document also outlines core topics like aircraft configurations, flight instruments, aerodynamic forces, airplane performance, stability, and dynamic stability to be covered.
Formation FI(A) : La météo (Exposé AéroPyrénées)Softeam agency
Exposé sur la météo, réalisé dans le cadre de ma formation FI (Flight Instructor) avion chez Aéro Pyrénées à Toussus (LFPN).
Attention, ce support de formation peut contenir des erreurs éventuelles. Je vous recommande de vous rapprocher de votre FI attitré pour vos cours théoriques.
Certaines images et photographies sont issues de captures écrans depuis Google.
Design and analysis of bodyworks of a formula style racecareSAT Journals
Abstract: The aim was to develop a body of the racecar with the proper studies and analyses, taking into account several factors, to present an optimum structure as a final result. These factors include, but are not limited to, weight, cost, drag resistance, functionality and aesthetics. The expected product is to not just be appealing to the eye but also increase the performance of the vehicle. Additional objectives include being able to accommodate the budget while maintaining a highly competitive level to perform well in on the race track. The new design will reduce the weight of the prototype and as well as the air drag, taking into consideration the ground effects desired to be implemented in the vehicle as a crucial factor. Moreover, the new body will be easier to dismantle reducing the service time. Keywords: drag resistance, aesthetics, performance, weight, cost.
This document discusses vertical take-off and landing (VTOL) aircraft. It defines VTOL aircraft as those that can take off, hover, and land vertically. There are two main types of VTOL technology: rotorcraft like helicopters, cyclocopters, and gyrodynes that use rotating wings to generate lift; and powered-lift aircraft like tiltrotors, tiltwings, and tail-sitters that can direct engine thrust vertically for takeoff and landing. The document outlines the key characteristics and advantages of various VTOL aircraft types and concludes by discussing future developments including electric VTOL aircraft and flying taxi services.
This document outlines the course objectives and content for Aerodynamics 301A taught at Cairo University's Faculty of Engineering. The course aims to teach students: 1) how to predict aerodynamic forces on aircraft components and whole aircraft; 2) how to determine air properties moving internally through engines; and 3) how to apply various aerodynamic principles to different applications. The course covers topics such as the governing equations of fluid motion, potential flow theory, and finite wing theory.
The document discusses vortex theory and Prandtl's lifting-line theory for analyzing the aerodynamics of finite wings. It introduces key concepts like downwash, trailing vortices, Helmholtz's vortex theorems, and the Biot-Savart law. The lifting-line theory models the wing as a bound vortex filament with varying circulation strength. This allows determining the induced downwash and angle of attack distributions. Prandtl's fundamental equation relates the circulation distribution to the wing geometry and twist. The lifting-line theory provides insights into the relationship between wing shape and lift distribution.
ME438 Aerodynamics is offered by Dr. Bilal Siddiqui to senior mechanical engineering undergraduates at DHA Suffa University. This lecture set is about prediction of lift on thin cambered airfoils.
This document provides an overview of aircraft landing gear systems. It describes the main components, including the types of landing gear arrangements (tail wheel, tandem, tricycle), construction details, alignment and retraction mechanisms, nose wheel steering, braking systems, tires, and antiskid systems. The purpose of landing gear is to support the aircraft during landing and taxiing. Retractable gear stows in the fuselage or wings to reduce drag while flying. Nose wheel steering and braking systems provide directional control on the ground. Aircraft tires must withstand high loads and provide traction for takeoff and landing. Antiskid systems help maintain braking effectiveness.
aircraft static and dynamic stability,longitudinal and lateralJini Raj
This document discusses the theory of flight stability. It defines three types of stability - dynamic, static, and inherent stability. It then discusses the three axes of stability in more detail: longitudinal stability around the lateral axis affected by horizontal stabilizer and center of gravity position, lateral stability around the longitudinal axis created through dihedral, keel effect, and sweepback wings, and directional stability around the vertical axis provided by the vertical tail surface.
Basic Info regarding making a RC aeroplaneZubair Ahmed
The document provides information on the control surfaces and aerodynamic components of an aircraft. It discusses that elevators control pitch, ailerons control roll, and the rudder controls yaw. It also mentions vertical and horizontal stabilizers provide stability and prevent pitching and yawing motions. The document further provides details on requirements, wing design and construction, airfoils, servos, engines, batteries, and tips for stability.
This document provides an overview of aeroelasticity, including its history, classifications, and precautions. It discusses how aeroelasticity studies the interaction between inertial, structural and aerodynamic forces. The document outlines the necessity of studying aeroelasticity effects for rotor design, wind energy, and to understand catastrophic failures. It then describes different types of static and dynamic aeroelasticity like divergence, control reversal, flutter, buffeting, and transonic phenomena. Precautions like testing and analysis are discussed.
This document provides an overview of aircraft wings, including their:
- Historical development from ancient kites to the Wright brothers' fixed-wing aircraft.
- Construction, with internal structures like ribs, spars, stringers, and skin covering the framework. Wings also contain fuel tanks, flaps, and other devices.
- Functions, as wings generate lift through Bernoulli's principle and critical angle of attack. Wing design factors like aspect ratio and camber also affect lift.
- Types based on position (fixed or movable) and structure (cantilever or strut-braced). Stability devices like ailerons and flaps are also described.
- Unconventional designs that
Support de cours pour la formation à la variante EFIS (Electronic Flight Instruments System) pour Glass Cockpit Garmin G1000.
Attention, ce support de formation peut contenir des erreurs éventuelles. Je vous recommande de vous rapprocher de votre FI attitré pour vos cours théoriques.
Certaines images et photographies sont issues de captures écrans depuis Google. Certains contenus sont issus de la documentation officielle de Garmin.
1) O documento descreve os principais componentes e classificações de helicópteros, incluindo os rotores, grupo motopropulsor, estrutura e tipos de rotores.
2) Os três tipos principais de giroaviões são o helicóptero, o autogiro e o giródino. O helicóptero pode voar verticalmente e em voo estacionário enquanto os outros não.
3) Os helicópteros são classificados de acordo com a configuração dos rotores, como rotor simples, rotor co-axial e rotor lado a lado.
This document discusses aircraft structural design limits and flight envelopes. It explains that flight envelopes graphically show the speed and load factor limits an aircraft can withstand based on factors like stall speed and maneuvering capabilities. The curves account for factors like altitude and critical Mach number. Load factors in the flight envelope are determined based on expected maneuvering loads and gust loads, with statistical analysis used to estimate extreme loads the aircraft may encounter over its operational life. Structural design limits like limit load, proof load, and ultimate load are set to ensure the aircraft can withstand expected loads with safety margins.
The document discusses solar powered aircrafts. It provides an introduction to solar powered planes, explaining that they use solar panels on their wings to gather solar energy and recharge batteries that power propellers, allowing the planes to stay airborne for up to 26 hours. It then covers various topics related to solar aircrafts, including their concept and working, evolution over time, types that exist, challenges they face, and specifics of the Solar Impulse aircraft including its specifications and flight achievements. Advantages are renewable energy source and lack of emissions, while disadvantages include inefficiency of solar panels and reliance on sunlight.
The document discusses various techniques for reducing vibration in helicopters, including passive, active, and semi-active methods. Passive techniques like tuned mass absorbers and blade design optimization provide moderate vibration reduction but with a significant weight penalty. Active concepts like higher harmonic control and individual blade control generate unsteady loads to cancel vibrations, but require external power. Semi-active systems modify structural properties using small amounts of power. The most successful current method is active control of structural response, which places actuators throughout an airframe to reduce vibrations measured by sensors.
Morphing Aircraft Technology – New Shapes for Aircraft Wing DesignMani5436
Morphing aircraft are multi-role aircraft that change their external shape substantially to adapt to a changing mission environment during flight.
Morphing poses several unique challenges when the wing loading is high. Very flexible materials are the designer’s first choice because they are easily reshaped.
he current use of multiple aerodynamic devices (such as flaps and slats) represents a simplification of the general idea behind morphing. Traditional control systems (with fixed geometry and/or location) give high aerodynamic performance over a fixed range and for a limited set of flight conditions.
This document discusses various aerodynamic characteristics of airfoils and wings. It describes how aerodynamic forces are generated by pressure and shear stress distributions on surfaces. It also defines key terms like lift, drag, angle of attack, center of pressure, aerodynamic center. Methods to increase lift or reduce drag like high-lift devices, supercritical airfoils, and winglets are explained. Different types of airfoils and their characteristics are also summarized.
Morphing of Aircraft Wings
This document discusses morphing technology for aircraft wings. Morphing allows wings to change shape to better match flight conditions. It can improve performance, efficiency, and adaptability. Wing morphing technologies include folding, sweeping, extending wings, and changing camber. This allows control of wing area, aspect ratio, and sweep angle. Shape memory alloys are used for actuation components. Advantages of morphing wings include improved performance, control, stealth, reduced drag and weight. Challenges remain in developing morphing wing technologies that can withstand flight conditions.
A Good Effect of Airfoil Design While Keeping Angle of Attack by 6 Degreepaperpublications3
Abstract: Airfoil is a shape of wing or blade of (a propeller, rotor or turbine) by which a fluid generates an aerodynamic force. The component of this force perpendicular to the direction of its speed is called lift force and the component parallel to its speed is called drag forces. Here we see that if we set the angle of attack by 6 degree in fluid NACA0012 we found the aerodynamic forces with suitable positive result our research is totally based on iterations method and based on the help of cfd software.
The document discusses aerodynamic analysis of the NACA 0012 airfoil using computational fluid dynamics (CFD). CFD simulations were performed in ANSYS Fluent to analyze flow behavior and calculate aerodynamic forces at varying angles of attack from 0 to 20 degrees. The results obtained from the CFD analysis matched theoretical predictions and experimental data. Key parameters like pressure and velocity distributions, lift and drag coefficients, and lift to drag ratios were evaluated to understand airfoil performance.
Aerodynamic Analysis of the Liebeck L2573 High-Lift AirfoilTodd Ramsey
The document analyzes the L2573 high-lift airfoil using computational fluid dynamics software to determine lift, drag, and moment coefficients and compare to previous published results. Flow separation was visualized beginning around 14 degrees angle of attack. Coefficient values matched closely with the original published data. The airfoil was designed to generate a lift coefficient of 0.68 near 5 degrees angle of attack, avoiding flow separation at the design point through boundary layer control.
This document summarizes an experimental study that investigated the effect of multiple wings on lift and drag forces. Researchers constructed a model with three symmetric airfoils spaced 12cm apart and tested it in a wind tunnel at various angles of attack up to 20 degrees. Results showed that lift and pressure coefficients generally increased with angle of attack for each airfoil, while drag coefficient slightly decreased. The multiple wing configuration was found to increase lift compared to a single airfoil.
1. An airfoil produces both lift and drag when placed in an airstream. Lift is many times greater than drag and is produced partly due to lower pressure over the upper surface of the wing according to Bernoulli's theorem.
2. The pressure distribution around an airfoil changes with angle of attack. At low angles, minimum pressure is further aft while at high angles it moves forward, increasing the adverse pressure gradient. Beyond a critical angle, the airflow separates, reducing lift.
3. Stall occurs when the adverse pressure gradient becomes too great for the airflow to overcome, causing it to separate from most of the wing surface. This reduces lift and increases drag sharply. Stall can be alleviated by
This document analyzes the aerodynamic performance of three different wing configurations for unmanned air vehicles (UAVs) using computational fluid dynamics (CFD). The three wings analyzed are a hybrid wing, joined wing, and tailless wing. CFD simulations were run at varying Mach numbers and angles of attack. Results show the tailless wing generates the lowest vortices and has the highest lift-to-drag ratio and stall angle, indicating it provides the best aerodynamic performance of the three wings analyzed for UAV applications.
This document discusses the four main forces that act on an aircraft in flight: thrust, weight, lift, and drag. It provides descriptions of each force and how they relate to one another. It also examines concepts like the aerodynamic resultant, lift and drag coefficients, and the lift to drag ratio. Angle of attack and its effect on lift and drag generation are explored. Finally, the different types of drag are defined and described in more detail.
AbstractGenerally, the wind tunnel experiment is used to gauge .docxbartholomeocoombs
Abstract
Generally, the wind tunnel experiment is used to gauge the drag and lift forces affecting an aircraft. The current experiment measured the drag and lift forces of a small wing at different angles of attacks with an increment of 2 degrees from -10. The results indicated a minimum and maximum lift coefficient of 0.14 and 0.65 respectively. Likewise, the maximum and minimum drag force was 0.24 and 0.05 respectively. On the calculation of the drag and lift coefficients, the stall angle occurred during the 12th angle of attack at a lift force of 0.38 and drag force of 0.17
Introduction
Generally, all atmospheric flying objects such as aircraft, ships, and vehicles need to undergo several Computational Fluid dynamics (CFD) simulations and wind tunnel tests in order to improve their designs. Accordingly lift and drag force tests are some of the most critical tests that such bodies go through. The phenomenon of Lift and drag is quite complicated and is hypothesized for better understanding by potential flow and boundary layer theory which has good agreements with experimental results. Generally, lift and drag forces are derived from two equations:
Lift Force FL= CL A V2/2
Drag force FD = CD A V2/2
Where, A is the projected area of the object, V is the freestream air velocity, ρ is the air density, and Cl and CD are the lift coefficients and drag coefficients respectively. Notably, the lift and drag of a wing is a function of multiple variables such as the angle of attack, airspeed, and cross-sectional geometry. An increase in the angle of attack raises the lift and drag up to a critical value upon which any increase leads to a sharp decrease in lift. Typically, this is referred to a stalling. Accordingly, this experiment measures the lift and drag of a model wing in order to determine its lift and drag coefficients at a specific speed.
Description of Work
In completing the experiment, three main pieces of equipment were used: the wind tunnel (see figure 1), pilot tube, and a small wing. Accordingly, the experiment was designed to gauge the lift and drag that were measured using the gauges. On the other hand, the pilot tube was used to measure the dynamic pressure. Typically, the pilot tube uses a manometer to measure pressure as air pushes the wing. Prior to beginning the experiment, the wing was mounted in the wind tunnel and the lift and scale readings confirmed to be zero. The wind tunnel was then adjusted for maximum velocity. The dynamic pressure was then measured changing the angle of attack with +/- 2 degrees after each measurement. This step was repeated until the stall angle was exceeded.
Figure 1. Wind Tunnel Device
Results and Discussion
Following the completion of the experiment, all the data was tabulated in excel for the purposes of calculating the lift coefficient and drag coefficient. Table 1 below summarizes the values for lift and drag coefficients for each angle of attack used in .
Airfoil Terminology, Its Theory and Variations As Well As Relations with Its ...paperpublications3
This document discusses airfoil terminology, theory, and variations in lift and drag forces. It begins with definitions of key airfoil terms like lift, drag, angle of attack, and pressure distributions. It then covers thin airfoil theory, relating angle of attack to coefficients of lift and drag. Derivations of thin airfoil theory and the relationship between various aerodynamic coefficients are provided. Finally, it examines static pressure and velocity contours around sample airfoils at different angles of attack. In summary, the document provides an overview of airfoil aerodynamic fundamentals including terminology, theoretical models, and illustrative computational fluid dynamics results.
The document summarizes a computational fluid dynamics study of flow over clean and loaded wings using ANSYS Fluent. It describes simulating flow over an airfoil at angles from 0-20 degrees both with and without a missile model attached. The results show that boundary layer separation begins around 15 degrees for the clean wing and occurs at a lower angle for the loaded wing. However, issues with meshing prevented analysis of the loaded wing case. Increasing angle of attack was found to increase lift forces until stall occurred due to vortex shedding beyond 20 degrees.
The document analyzes the effect of adding dimples to the surface of an airfoil wing. It discusses how dimples can delay flow separation and transition the boundary layer from laminar to turbulent, reducing pressure drag. The study models a wing with and without dimples using design software to analyze lift and drag at different angles of attack. The results show that a wing with dimples has an increased critical angle of stall and variations in lift and drag compared to a smooth wing. Future work could include building prototypes to validate the numerical analysis.
CFD Analysis of Delta Winged Aircraft – A ReviewIRJET Journal
This document reviews computational fluid dynamics (CFD) analysis that has been conducted on delta wing aircraft and airfoils with surface modifications like dimples. Several studies are summarized that used CFD to analyze how dimples affect lift and drag on airfoils at various angles of attack. Dimples function similarly to vortex generators by creating vortices that delay flow separation and reduce pressure drag. Researchers have found that dimples can increase an aircraft's aerodynamic performance characteristics and maneuverability by reducing drag and stall. The document reviews multiple studies that analyzed different dimple shapes and configurations on symmetric and asymmetric airfoil profiles.
Analysis of Ground Effect on a Symmetrical AirfoilIJERA Editor
A Detailed Study and Computational Fluid Dynamics investigation was conducted to ascertain and highlight the
different ways in which ground effect phenomena are present around a symmetrical aerofoil-NACA 0015- when
in close proximity to the ground. The trends in force and flow field behaviour were observed at various ground
clearances, for different angle of attack. The analysis was carried out by varying the angle of attack from 00 to
100 and ground clearance of the trailing edge from minimum possible value to one chord length. It was found
that high values of pressure coefficient are obtained on the lower surface when the airfoil is close to the ground.
This region of high pressure extended almost over the entire lower surface for higher angles of attack. As a
result, higher values of lift coefficient are obtained when the airfoil is close to the ground. The flow accelerates
over the airfoil due to flow diversion from the lower side and higher mean velocity is observed near the suction
peak location. The pressure distribution on the upper surface did not change significantly with ground clearance
for higher angles of attack. The lift was found to drop at lower angles of attack at some values of ground
clearance due to suction effect on the lower surface as the result of formation of a convergent–divergent passage
between the airfoil and the ground plate. The values of drag coefficient were also noted for different ground
clearance, which is found to be decreasing as the airfoil is approaching to a closer ground clearance. This ground
effect is analyzed using FLUENT 5/6 code.
Swept wings reduce wave drag at transonic and supersonic speeds due to a reduced relative airflow velocity. However, swept wings also generate less lift due to this reduced velocity. Delta wings are used for transonic and supersonic aircraft to reduce wave drag through vortex lift, providing high maximum lift despite a small lift slope. For wing-body combinations, the lift can be approximated as the wing lift alone, including the portion masked by the fuselage. Drag on airfoils and wings is caused by pressure and skin friction. Pressure drag results from boundary layer separation and skin friction drag from shear stresses. Formulas are provided for estimating profile drag on laminar and turbulent flat plates in incompressible flow.
For Video Lecture of this presentation: https://youtu.be/NAjezfbWh4Y
The topics covered in this session are, drag, categories of drag, drag polar equation and drag polar graph, drag polar derivation, induced drag coefficient.
Attention! "Gate Aerospace Engineering aspirants", A virtual guide for gate aerospace engineering is provided in "Age of Aerospace" blog for helping you meticulously prepare for gate examination. Respective notes of individual subjects are provided as 'Embedded Google Docs' which are frequently updated. This comprehensive guide is intended to efficiently serve as an extensive collection of online resources for "GATE Aerospace Engineering" which can be accessed free of cost. Use the following link to access the study material
https://ageofaerospace.blogspot.com/p/gate-aerospace.html
L2 Unit 101 Aircraft Flight Principles & TOF Master 2022 04 Oct 22.pptxMarkWootton9
This document provides an overview of aerodynamics theory and aircraft flight principles. It discusses:
1) Bernoulli's principle and how it explains the relationship between pressure and velocity of fluid flow, generating lift over an airfoil.
2) The four main forces acting on an aircraft in flight - lift, drag, thrust, and weight. It also explains how control surfaces like elevators, ailerons, and rudders control the aircraft's pitch, roll, and yaw.
3) Characteristics of subsonic, transonic, and supersonic airflow and how air behaves at different speeds in relation to the speed of sound.
4) Key aerodynamic terms like angle of attack
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
The flow velocity over airfoils increases over the convex surface resulting in lower average pressure on the 'suction' side of the airfoil compared with the concave or 'pressure' side of the airfoil.
Meanwhile, viscous friction between the air and the airfoil surface slows the airflow to some extent next to the surface.
Airflow over an airfoil produces a distribution of forces over the airfoil surface.
Passive Bleed & Blow System for Optimized AirfoilsTyler Baker
This document summarizes a project investigating a passive bleed and blow system for optimized airfoils. A team of 5 students from different California universities designed, modeled, 3D printed, and tested different airfoil designs in a wind tunnel. Computational fluid dynamics simulations of airfoils with and without bleed and blow holes were performed. Preliminary 2D simulations showed reductions in drag of around 50% for an airfoil using the system, though with around a 20% reduction in lift. Further 3D simulations and physical testing are still needed to fully understand the benefits of the passive bleed and blow system.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
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The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
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1. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
MAE 123 : Mechanical Engineering Laboratory II - Fluids
Laboratory 7: Lift and Drag of an Airfoil
Dr. J. M. Meyers | Dr. D. G. Fletcher | Dr. Y. Dubief
2. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
2
Basic Forces of an Aircraft
Four main forces act on an aircraft in flight: Thrust (if the aircraft is powered), Drag, Lift, and Weight
We are concerned only with Lift and Drag at the moment.
The main contribution to lift (and substantial drag at times) comes from the wing which has a certain
airfoil shape or airfoil section (see above)
Airfoils shapes are designed to provide high Lift values at low Drag for given flight conditions
Conventional aircraft wings often use moving surfaces (flaps and slats) to adapt to different
conditions however our study will just focus on baseline airfoil shape
Airfoil Section
Side-view shape of wing
3. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
3
Flow Over an Airfoil
The drawing above illustrates a common incorrect description of lift for an airfoil, which is the basic
shape of an air vehicle wing or a helicopter blade.
It basically states that owing to the longer flow path on the top surface, the flow reaches higher
velocity, which corresponds to lower pressure (remember Venturi effect?)
The pressure difference over the area of the airfoil provides a net upward force that is called Lift…
this is true
This is a typical shape for a subsonic airfoil - it is not symmetric but symmetric airfoils also produce
lift
4. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
4
Flow Over an Airfoil
The flow over the top of a lifting
airfoil does travel faster than the
flow beneath the airfoil.
But the flow is much faster than the
speed required to have the
molecules meet up at the trailing
edge.
In fact it is the turning of the flow
that's important, not the faster flow
owing to longer distance.
Circulation!!!!
5. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
5
Other Applications
6. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
6
Terminology for Airfoils
Airfoils have a leading edge and a trailing edge, and are usually designed with different top and
bottom surface curvatures to promote the flow induced pressure difference that causes lift.
The chord is defined as the line connecting the leading edge and the trailing edge
Camber is defined as the maximum distance from the chord to either surface
Chord length, , is the overall airfoil length
Angle of attack, , is defined as the angle between the extended chord and the relative fluid flow
direction (usually horizontal)
7. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
7
Basic Forces on a Wing
• Aerodynamic forces result from the pressure
distribution over the surface
• One useful way to evaluate the aerodynamic forces is
to use pressure taps to record the distribution and to
integrate the distribution to find the net force
• For lift this integration is concerned with the pressure
distribution in the vertical direction, while for drag
the horizontal pressure distribution is important
• You can see from the image how the surface “pushes
back” with a force against the pressure, which always
acts normal to the surface
• Surface curvature is IMPORTANT
8. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
8
Angle of Attack and Stall
• Two mechanisms are used to generate Lift
• The first is an asymmetric profile (about the chord –
defined in previous slide). This is often used for subsonic
flight applications.
• The second is to incline the airfoil at an angle relative to
horizontal, which is usually the “relative wind angle”
• For low values of this angle (angle of attack) the flow
remains attached on both surfaces
• For higher angles of attack separation occurs that
increases drag and reduces lift.
• Eventually, the airfoil (and vehicle!) reaches a stall
condition, where the pressure distribution on the top
and bottom are equal
9. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
9
Surface Pressure Distribution Measurement
• As we have stated, one way to evaluate the aerodynamic forces is to measure the surface
pressure distribution and integrate that over the airfoil area
• Taps can be placed at various locations on the surface and tubes run out the side of the airfoil to
bring the pressure information to a transducer
• Pressure acts normal to the surface, so the curvature must be known at the tap location, and the
tap samples the pressure over a finite area surrounding the tap
• The angle represents the angle between the chord normal and the surface normal at the tap
• NOTE that the angle relative to the wind influences the pressure distribution
The aerodynamic performance of airfoil sections can be studied most easily by
reference to the distribution of pressure over the airfoil
10. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
10
Surface Pressure Distribution Measurement
• Recall that the wind tunnel has a reference pressure tap located upstream of the test section and
that the pressure there is
= ℎ − ℎ
• From the Bernoulli relation we can find the corresponding velocity along a horizontal stream line:
=
2 ℎ − ℎ
• The 16 pressure taps provide pressure values determined from the manometer as:
= ℎ − ℎ
• The total force the pressure distribution exerts on the wing is:
= −( ∙ )
• The surface normal angle, , varies with pressure tap location!!!
• As the wind is traveling in the x-direction, we can decompose this force into horizontal and
vertical components to recover the aerodynamic forces:
= =
Lift: Drag:
The aerodynamic performance of airfoil sections can be studied most easily by
reference to the distribution of pressure over the airfoil
11. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
11
Surface Pressure Distribution Measurement
• Taking account of both the angle of the surface normal relative to the chord normal at each tap
and the angle of attack, the force evaluation in the vertical direction is:
= = ! − cos(% + )
• As we do not have a continuous pressure distribution, we evaluate this with a numerical
summation:
= = ' − cos(% + ) Δ
• A similar expression can be derived for the Drag Force:
= = ' − sin(% + ) Δ
12. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
12
Surface Pressure Distribution Measurement
To handle different wind conditions, non-dimensional (unitless!) representations are used based on the
pressure coefficient:
+,-
=
−
1
2
/
=
−
0 0 =
1
2
/
Here we will define the
dynamic pressure as:
Pressure Coefficient
+, is the difference between local static pressure and free-stream (at ∞) static pressure, non-
dimensionalized by the free-stream dynamic pressure.
What does an airfoil pressure coefficient distribution look like? We generally plot +, vs. 3/5.
+, at the airfoil stagnation point is unity. Why is this? Think of Bernoulli relation and definition of the
stagnation point (67 8 = 0).
It then rapidly decreases on both the upper and lower surfaces and finally recovers to a small positive
value of +: near the trailing edge
positive
pressure
negative
pressure
13. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
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Surface Pressure Distribution Measurement
Pressure Coefficient
The upper surface pressure is lower (plotted higher on the usual scale) than the lower surface +, in this
case… but it doesn't have to be.
The lower surface sometimes carries a positive pressure, but at many design conditions is actually
pulling the wing downward.
The pressure at the trailing edge is related to the airfoil thickness and shape near the trailing edge.
Large positive values of +: at the trailing edge imply more severe adverse pressure gradients.
Pressure recovery region: Pressure increases from its minimum value to the value at the trailing edge.
This adverse pressure gradient is associated with boundary layer transition and possibly separation, if
the gradient is too severe… which occurs at higher angles of attack!!!
14. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
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Surface Pressure Distribution Measurement
• It is common to also common to represent Lift and Drag non-dimensionally (no units!) as the Lift
and Drag coefficient:
+; =
0 <
+= =
0 <
< is known as the wing
planform area
Lift and Drag Coefficients
Wing Planform Area, >
15. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
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Flow Separation
16. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
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Surface Pressure Distribution Measurement
+,-
=
−
0
+; =
0 <
+= =
0 < 0 =
1
2
/
Reynolds number
dependent
Critical Angle
of Attack
?@ ?@
?A
17. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
17
Surface Pressure Distribution Measurement
+,-
=
−
0
+; =
0 <
+= =
0 < 0 =
1
2
/
18. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
18
Experiment
Objectives
• Understand the principles of Lift and Drag on an aerodynamic surface
• Acquire a pressure distribution over a body and approximate Lift and Drag
• Understand the importance of pressure, lift, and drag coefficient non-dimensional parameters
• Understand the behavior of flow separation
• Understand how flow separation behavior leads to stall (loss of lift)
19. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
19
Experiment
Procedure
• Experiment will make use of a NACA 2415 airfoil mounted into the Flowtek 1440 1’x1’ wind
tunnel
• Start the wind tunnel
• Set the desired angle of attack and adjust the RPM to obtain the desired upstream air velocity,
(consult your data from the Venturi lab)
• Record the pressure readings for the 16 taps
• Rotate airfoil and readjust speed.
• Determine the airfoil stall angle for both positive and negative angle
• Use tufts as a visual tool for stall.
20. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
20
Experiment
Results
• Determine the pressure coefficient distribution over the airfoil for various air speeds and angles
of attack
• Determine the lift and drag coefficients for various air speeds and angles of attack
• Determine Reynolds number for all flow conditions… this will be used to compare with existing
experimental data
21. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
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Experiment
Pressure Tap B (%c) C (%c) D [rad] EF [m2]
Leading Edge 0 0
1 1.193 2.657 0.9006 0.002577
2 5.688 5.374 0.3688 0.003374
3 14.89 7.944 0.1838 0.004548
4 25.40 9.185 0.05831 0.00561
5 39.44 9.278 -0.03975 0.006633
6 54.25 8.155 -0.1037 0.006633
7 68.64 6.308 -0.1503 0.006785
8 84.16 3.628 -0.2111 0.01107
Trailing Edge 100 0
Pressure Tap B (%c) C (%c) D [rad] EF [m2]
Leading Edge 0 0
9 1.451 -2.213 0.7282 0.002502
10 6.730 -4.301 0.2264 0.002994
11 14.11 -5.353 0.08516 0.003411
12 21.70 -5.688 0.00835 0.00474
13 35.08 -5.467 -0.03805 0.006444
14 49.93 -4.673 -0.06709 0.006595
15 63.99 -3.585 -0.08428 0.00705
16 80.72 -2.083 -0.1027 0.01251
Trailing Edge 100 0
Upper
Surface
Lower
Surface
NACA 2415
Airfoil
22. ME 123: Mechanical Engineering Lab II: Fluids
Laboratory 7: Lift and Drag of an Airfoil
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References
1. J.D. Anderson, “Fundamentals of Aerodynamics”,
2. Kuethe and Chow, “Foundations of Aerodynamics: Bases of Aerodynamic Design,” 4th edition, John Wiley and
Sons, 1986
3. Abbott and von Doenhoff, “Theory of Wing Sections: Including a Summary of Airfoil Data,”