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.
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 the basics of airfoil design and development. It provides a brief history of airfoil research from the late 1800s through modern times. Key topics covered include [END SUMMARY]
ME 438 Aerodynamics is a course taught by Dr. Bilal Siddiqui at DHA Suffa University. This set of lectures start from the basic and all the way to aerodynamic coefficients and center of pressure variations with angle of attack.
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 discusses high-speed aerodynamics and several key concepts, including that compressibility effects become important at transonic and supersonic speeds. It describes research done on high-speed aircraft like the Bell X-1, which broke the sound barrier in 1947. The document also covers topics like the speed of sound, different flight regimes (subsonic, transonic, supersonic, hypersonic), and shock wave patterns that form at supersonic speeds.
A helicopter is an aircraft that is lifted and propelled by one or more horizontal rotors, each
consisting of two or more rotor blades. The main objective of this seminar topic is to study the basic
concepts of helicopter aerodynamics. The forces acting on helicopter i.e. lift, drag, thrust and weight
are considered for developing analytic equations. The main topics that are discussed include blade
motions like blade flapping, feathering and lead-lag. The effect of stall on helicopter blade flapping is
studied and it was noticed that there is a sudden lift drop at this stall condition. It was also found that
dynamic stall occurs due to rapidly changing angle of attack, which inturn affect the air flow over the
airfoil. Blade flapping angle and induced angle of attack are the main parameters concerned with stall.
The theory behind blade element analysis has been inferred in detail. The importance of all these in the
present scenario are also taken into consideration
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.
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 the basics of airfoil design and development. It provides a brief history of airfoil research from the late 1800s through modern times. Key topics covered include [END SUMMARY]
ME 438 Aerodynamics is a course taught by Dr. Bilal Siddiqui at DHA Suffa University. This set of lectures start from the basic and all the way to aerodynamic coefficients and center of pressure variations with angle of attack.
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 discusses high-speed aerodynamics and several key concepts, including that compressibility effects become important at transonic and supersonic speeds. It describes research done on high-speed aircraft like the Bell X-1, which broke the sound barrier in 1947. The document also covers topics like the speed of sound, different flight regimes (subsonic, transonic, supersonic, hypersonic), and shock wave patterns that form at supersonic speeds.
A helicopter is an aircraft that is lifted and propelled by one or more horizontal rotors, each
consisting of two or more rotor blades. The main objective of this seminar topic is to study the basic
concepts of helicopter aerodynamics. The forces acting on helicopter i.e. lift, drag, thrust and weight
are considered for developing analytic equations. The main topics that are discussed include blade
motions like blade flapping, feathering and lead-lag. The effect of stall on helicopter blade flapping is
studied and it was noticed that there is a sudden lift drop at this stall condition. It was also found that
dynamic stall occurs due to rapidly changing angle of attack, which inturn affect the air flow over the
airfoil. Blade flapping angle and induced angle of attack are the main parameters concerned with stall.
The theory behind blade element analysis has been inferred in detail. The importance of all these in the
present scenario are also taken into consideration
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.
Analysis of wings using Airfoil NACA 4412 at different angle of attackIJMER
This document summarizes wind tunnel testing of the NACA 4412 airfoil at different angles of attack. The testing was conducted to analyze lift and drag forces on the airfoil at varying angles. The results found that lift increases with angle of attack until a maximum is reached, after which drag becomes dominant and stall occurs. Graphs and tables presented in the document compare experimental pressure and friction coefficient data from the wind tunnel tests to computational fluid dynamics simulations using different turbulence models. The models were able to accurately predict flow separation locations and other characteristics.
Naca 2415 finding lift coefficient using cfd, theoretical and javafoileSAT Journals
Abstract In this paper we have studied the experimental characteristic graph of NACA 2415.The experimental graphs were taken from the book, “Theory of wing section” by IRA H. ABBOTT. We used these graphs for the validation of our results. Then we use CFD to simulate the experimental flow conditions and check the results and compare them with the experimental results. We meshed the airfoil in ICEM CFD so that the meshing is very precise. We then calculate the NACA 2415 airfoil’s lift at different angle of attack theoretically and using CFD analysis and compare them with the experimental values. We find the errors between experimental and CFD values as well as experimental and theoretical values. We used another simulation software called Javafoil and used it for comparison. Keywords: Experimental, CFD, Theoretical, Javafoil
This document is a seminar report submitted by Dhanashree Manohar Waghmare on aircraft drag reduction techniques. The report contains an introduction on the importance of reducing aircraft drag. It then provides a literature review on relevant topics like aerodynamics, fluid mechanics, previous studies on drag reduction. The objectives are to study aerodynamic principles, forces on aircraft, types of drag and reduction methods. The body of the report discusses these topics in detail with diagrams. It covers concepts like aerodynamics, aircraft wings, forces, types of drag and techniques to reduce skin friction, lift-induced and wave drag. The report aims to provide a comprehensive overview of aircraft drag and methods to reduce it.
A comparative flow analysis of naca 6409 and naca 4412 aerofoileSAT Publishing House
This document analyzes and compares the flow properties of two airfoil profiles, the NACA 6409 and NACA 4412, using computational fluid dynamics (CFD) modeling in ANSYS. The analysis examines pressure distribution, lift and drag coefficients at varying angles of attack. The NACA 4412 was found to have better lift-to-drag ratio performance and is more efficient for practical applications compared to the NACA 6409.
This document summarizes experiments performed on NACA 4412 airfoils in Cal Poly's low speed wind tunnel. Three experiments were conducted: 1) force balance tests on two finite wings to determine coefficients, 2) pressure measurements on a full-span wing to calculate coefficients, and 3) wake rake tests to determine total drag coefficient. The force balance showed lift coefficient increasing pre-stall and dropping post-stall. Pressure data matched theoretical predictions and a NASA study. Lift was found to increase with angle of attack. The NACA 4412 performed best at low angles of attack, suited for a cruiser aircraft.
EFFECTS OF SUNLIGHT INTENSITY ON TURBO JET ENGINE OF AIRCRAFT IAEME Publication
The reasons behind the raise of the temperature of turbo jet engine of aircrafts was investigated which leads to damaging the engine and costs the government huge expenses in case the plane is on ground and costs lives and expenses in case the aircraft is in flight. My daily study over the course of a year has proved the effect of sunlight on the temperature of turbo jet engine over the city of Kirkuk which lies on longitude 44.4 latitude 35.5.
This is the presentation on flow past an airfoil . An airfoil-shaped body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The component parallel to the direction of motion is called drag. Subsonic flight airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric curvature of upper and lower surfaces.
This document provides an overview of principles of flight, including subsonic, transonic, and supersonic aerodynamics. It discusses properties of fluids, aerodynamic forces, airfoil theory, and airplane performance. A key topic is transonic aerodynamics, explaining how shock waves form as local airflow exceeds the speed of sound. This leads to sudden increases in drag, loss of lift, and control issues. Solutions like supercritical wing sections can raise the critical Mach number and widen the safe speed range.
Estimation of Damping Derivative of a Delta Wing with Half Sine Wave Curved L...IOSR Journals
1) The document analyzes the effect of angle of attack on the damping derivative of a delta wing with a half sine wave curved leading edge for attached shock cases in supersonic flow.
2) A strip theory combined with Ghosh's piston theory is used to relate pressure on the wing surface to equivalent piston Mach number, allowing calculation of stability derivatives.
3) Results show the damping derivative increases linearly with angle of attack up to a Mach-dependent limit, and decreases with increasing Mach number and with the pivot position moving aft.
This document provides an overview of a seminar presentation on supersonic planes. It includes sections on the introduction, history, theories, engine types, and applications of supersonic flight. The presentation was given by Jahani and Abdolzade for a fluid mechanics course taught by Dr. Hoseinalipour in spring 2013.
IRJET-Subsonic Flow Study and Analysis on Rotating Cylinder AirfoilIRJET Journal
This document presents a study on modifying the lift characteristics of a conventional symmetrical airfoil (NACA 0012) by adding a rotating cylinder. A numerical analysis and computational fluid dynamics simulation were conducted. Two cases were considered: a cylinder with 13mm diameter located at the 0.125 chord point, and a 15mm cylinder at the 0.25 chord point. The presence of a rotating cylinder was found to significantly increase the airfoil's lift at zero angle of attack through momentum injection, by up to 100%. It also delayed stall characteristics. The document outlines the methodology, including the airfoil geometry, range of air velocities and cylinder rotation speeds studied, and equations used to model static and total pressure.
This document describes a computational fluid dynamics (CFD) analysis of flow over NACA airfoils conducted using ANSYS. Three airfoils - NACA 6409, NACA 4412, and NACA 0012 - were analyzed. Pressure and velocity distributions, as well as lift and drag coefficients, were computed for the NACA 6409 and NACA 4412 airfoils. The NACA 4412 airfoil was found to have better lift to drag ratio characteristics, making it more efficient. Additionally, the effect of varying angle of attack on the lift and drag coefficients of the NACA 0012 airfoil was investigated.
This document describes a CFD modeling project of flow over a flat plate. It includes an introduction, literature review, experimental setup, observations, results, and conclusions section. The project involves using FLUENT software to analyze parameters like velocity, pressure, and temperature of cold air flowing over a flat plate. Graphs of velocity and pressure variations obtained from the CFD simulations are presented.
15 aerodynamic hazards high speed flight (1)stansellcp
The document discusses transonic flight and issues that can occur when passing through transonic speeds between Mach 0.75 to 1.2. It explains that the Mach number is the ratio of true airspeed to the speed of sound. It describes how shock waves can form when local airspeed exceeds the speed of sound, causing compressibility and potential airflow separation. This can increase drag and reduce lift. Passing the airplane's critical Mach number leads to a large increase in drag called drag divergence. Solutions like vortex generators are used to delay flow separation at transonic speeds and prevent control issues like Mach tuck or Dutch roll.
This report is a simulation for a flow over an airfoil "NACA 0009" at Reynolds number equals 1 million for four angles of attack using three different turbulence models and of cause a grid independence solution.
The goal of this study is to apply the knowledge obtained from studying in the university and self-learning in order to solve a specific task of finding the coefficient of drag and lift for the airfoil.
A youtube video made by me explaining how to simulate a flow over an airfoil: https://goo.gl/9VYRFM
Team members:
Ahmed Kamal Shalaby
Ahmed Gaber Ahmed
Esraa Mahmoud Saleh
The document discusses principles of flight for rotary wing aircraft, specifically focusing on propellers. It defines key terms like blade angle and angle of attack. It explains the aerodynamic forces acting on propeller blades, including lift, drag, thrust, and rotational drag. It also discusses how fixed and variable pitch propellers are affected by changes in airspeed, and factors that can cause take-off swings for nose-wheel and tail-wheel aircraft.
Numerical Investigation of the Perfomance of Convergent Divergent NozzleIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
The document summarizes the development and characteristics of several airfoil series developed by the National Advisory Committee for Aeronautics (NACA). It describes the early 4-digit and 5-digit series which used analytical equations to define airfoil shape based on camber and thickness. Later series like the 6-series used more advanced theoretical methods. The document provides details on naming conventions and equations used to define the geometry of airfoils within each series.
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 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.
Analysis of wings using Airfoil NACA 4412 at different angle of attackIJMER
This document summarizes wind tunnel testing of the NACA 4412 airfoil at different angles of attack. The testing was conducted to analyze lift and drag forces on the airfoil at varying angles. The results found that lift increases with angle of attack until a maximum is reached, after which drag becomes dominant and stall occurs. Graphs and tables presented in the document compare experimental pressure and friction coefficient data from the wind tunnel tests to computational fluid dynamics simulations using different turbulence models. The models were able to accurately predict flow separation locations and other characteristics.
Naca 2415 finding lift coefficient using cfd, theoretical and javafoileSAT Journals
Abstract In this paper we have studied the experimental characteristic graph of NACA 2415.The experimental graphs were taken from the book, “Theory of wing section” by IRA H. ABBOTT. We used these graphs for the validation of our results. Then we use CFD to simulate the experimental flow conditions and check the results and compare them with the experimental results. We meshed the airfoil in ICEM CFD so that the meshing is very precise. We then calculate the NACA 2415 airfoil’s lift at different angle of attack theoretically and using CFD analysis and compare them with the experimental values. We find the errors between experimental and CFD values as well as experimental and theoretical values. We used another simulation software called Javafoil and used it for comparison. Keywords: Experimental, CFD, Theoretical, Javafoil
This document is a seminar report submitted by Dhanashree Manohar Waghmare on aircraft drag reduction techniques. The report contains an introduction on the importance of reducing aircraft drag. It then provides a literature review on relevant topics like aerodynamics, fluid mechanics, previous studies on drag reduction. The objectives are to study aerodynamic principles, forces on aircraft, types of drag and reduction methods. The body of the report discusses these topics in detail with diagrams. It covers concepts like aerodynamics, aircraft wings, forces, types of drag and techniques to reduce skin friction, lift-induced and wave drag. The report aims to provide a comprehensive overview of aircraft drag and methods to reduce it.
A comparative flow analysis of naca 6409 and naca 4412 aerofoileSAT Publishing House
This document analyzes and compares the flow properties of two airfoil profiles, the NACA 6409 and NACA 4412, using computational fluid dynamics (CFD) modeling in ANSYS. The analysis examines pressure distribution, lift and drag coefficients at varying angles of attack. The NACA 4412 was found to have better lift-to-drag ratio performance and is more efficient for practical applications compared to the NACA 6409.
This document summarizes experiments performed on NACA 4412 airfoils in Cal Poly's low speed wind tunnel. Three experiments were conducted: 1) force balance tests on two finite wings to determine coefficients, 2) pressure measurements on a full-span wing to calculate coefficients, and 3) wake rake tests to determine total drag coefficient. The force balance showed lift coefficient increasing pre-stall and dropping post-stall. Pressure data matched theoretical predictions and a NASA study. Lift was found to increase with angle of attack. The NACA 4412 performed best at low angles of attack, suited for a cruiser aircraft.
EFFECTS OF SUNLIGHT INTENSITY ON TURBO JET ENGINE OF AIRCRAFT IAEME Publication
The reasons behind the raise of the temperature of turbo jet engine of aircrafts was investigated which leads to damaging the engine and costs the government huge expenses in case the plane is on ground and costs lives and expenses in case the aircraft is in flight. My daily study over the course of a year has proved the effect of sunlight on the temperature of turbo jet engine over the city of Kirkuk which lies on longitude 44.4 latitude 35.5.
This is the presentation on flow past an airfoil . An airfoil-shaped body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The component parallel to the direction of motion is called drag. Subsonic flight airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric curvature of upper and lower surfaces.
This document provides an overview of principles of flight, including subsonic, transonic, and supersonic aerodynamics. It discusses properties of fluids, aerodynamic forces, airfoil theory, and airplane performance. A key topic is transonic aerodynamics, explaining how shock waves form as local airflow exceeds the speed of sound. This leads to sudden increases in drag, loss of lift, and control issues. Solutions like supercritical wing sections can raise the critical Mach number and widen the safe speed range.
Estimation of Damping Derivative of a Delta Wing with Half Sine Wave Curved L...IOSR Journals
1) The document analyzes the effect of angle of attack on the damping derivative of a delta wing with a half sine wave curved leading edge for attached shock cases in supersonic flow.
2) A strip theory combined with Ghosh's piston theory is used to relate pressure on the wing surface to equivalent piston Mach number, allowing calculation of stability derivatives.
3) Results show the damping derivative increases linearly with angle of attack up to a Mach-dependent limit, and decreases with increasing Mach number and with the pivot position moving aft.
This document provides an overview of a seminar presentation on supersonic planes. It includes sections on the introduction, history, theories, engine types, and applications of supersonic flight. The presentation was given by Jahani and Abdolzade for a fluid mechanics course taught by Dr. Hoseinalipour in spring 2013.
IRJET-Subsonic Flow Study and Analysis on Rotating Cylinder AirfoilIRJET Journal
This document presents a study on modifying the lift characteristics of a conventional symmetrical airfoil (NACA 0012) by adding a rotating cylinder. A numerical analysis and computational fluid dynamics simulation were conducted. Two cases were considered: a cylinder with 13mm diameter located at the 0.125 chord point, and a 15mm cylinder at the 0.25 chord point. The presence of a rotating cylinder was found to significantly increase the airfoil's lift at zero angle of attack through momentum injection, by up to 100%. It also delayed stall characteristics. The document outlines the methodology, including the airfoil geometry, range of air velocities and cylinder rotation speeds studied, and equations used to model static and total pressure.
This document describes a computational fluid dynamics (CFD) analysis of flow over NACA airfoils conducted using ANSYS. Three airfoils - NACA 6409, NACA 4412, and NACA 0012 - were analyzed. Pressure and velocity distributions, as well as lift and drag coefficients, were computed for the NACA 6409 and NACA 4412 airfoils. The NACA 4412 airfoil was found to have better lift to drag ratio characteristics, making it more efficient. Additionally, the effect of varying angle of attack on the lift and drag coefficients of the NACA 0012 airfoil was investigated.
This document describes a CFD modeling project of flow over a flat plate. It includes an introduction, literature review, experimental setup, observations, results, and conclusions section. The project involves using FLUENT software to analyze parameters like velocity, pressure, and temperature of cold air flowing over a flat plate. Graphs of velocity and pressure variations obtained from the CFD simulations are presented.
15 aerodynamic hazards high speed flight (1)stansellcp
The document discusses transonic flight and issues that can occur when passing through transonic speeds between Mach 0.75 to 1.2. It explains that the Mach number is the ratio of true airspeed to the speed of sound. It describes how shock waves can form when local airspeed exceeds the speed of sound, causing compressibility and potential airflow separation. This can increase drag and reduce lift. Passing the airplane's critical Mach number leads to a large increase in drag called drag divergence. Solutions like vortex generators are used to delay flow separation at transonic speeds and prevent control issues like Mach tuck or Dutch roll.
This report is a simulation for a flow over an airfoil "NACA 0009" at Reynolds number equals 1 million for four angles of attack using three different turbulence models and of cause a grid independence solution.
The goal of this study is to apply the knowledge obtained from studying in the university and self-learning in order to solve a specific task of finding the coefficient of drag and lift for the airfoil.
A youtube video made by me explaining how to simulate a flow over an airfoil: https://goo.gl/9VYRFM
Team members:
Ahmed Kamal Shalaby
Ahmed Gaber Ahmed
Esraa Mahmoud Saleh
The document discusses principles of flight for rotary wing aircraft, specifically focusing on propellers. It defines key terms like blade angle and angle of attack. It explains the aerodynamic forces acting on propeller blades, including lift, drag, thrust, and rotational drag. It also discusses how fixed and variable pitch propellers are affected by changes in airspeed, and factors that can cause take-off swings for nose-wheel and tail-wheel aircraft.
Numerical Investigation of the Perfomance of Convergent Divergent NozzleIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
The document summarizes the development and characteristics of several airfoil series developed by the National Advisory Committee for Aeronautics (NACA). It describes the early 4-digit and 5-digit series which used analytical equations to define airfoil shape based on camber and thickness. Later series like the 6-series used more advanced theoretical methods. The document provides details on naming conventions and equations used to define the geometry of airfoils within each series.
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 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.
IRJET- CFD Approach of Joukowski Airfoil (T=12%), Comparison of its Aerodynam...IRJET Journal
The document presents a computational fluid dynamics study comparing the aerodynamic performance of NACA0012, NACA4412, and Joukowski (T=12%) airfoils at a Reynolds number of 3 million using the k-ε turbulence model. Graphs of lift and drag coefficients, pressure distributions, and maximum CL/CD ratios show that the NACA4412 airfoil performed best with higher lift, lower drag, and a maximum CL/CD ratio, indicating it may be better suited than the other airfoils tested for aerodynamic applications. The study also found the Joukowski airfoil results were similar to the NACA
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.
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.
Aerodynamic,rotor design and rotor performance of horizontal axis wind turbin...Sarmad Adnan
- The document discusses the aerodynamic principles governing wind turbines, including axial momentum theory and blade element theory.
- Axial momentum theory models the rotor as having infinite blades and analyzes the changes in wind speed and pressure upstream and downstream. It determines that the maximum power coefficient is 16/27 when the axial induction factor is 1/3.
- Blade element theory models the rotor as discrete blade elements and considers the lift and drag forces on each element based on local airfoil properties and wind velocities. Integrating these forces provides the total torque and power of the rotor.
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.
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.
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.
HydroFoil Simulation Using ANSYS FluentAhmed Gamal
The document discusses computational fluid dynamics (CFD) simulations performed to analyze flow around a hydrofoil. It describes the hydrofoil geometry and meshing process, which involved multiple meshing strategies to generate high quality meshes. It also covers important considerations for the CFD solver setup, such as choosing a pressure-based solver, initializing the solution, and selecting an appropriate turbulence model. The k-epsilon realizable model was used to model the fully turbulent, incompressible flow in 2D simulations of the hydrofoil at different angles of attack.
Hydrofoil Ship simulation Using Ansys FluentAhmed Gamal
This document discusses a CFD workshop report on analyzing hydrofoils for naval applications. It begins with introductions to hydrofoils, their history, and basic terminology. It then describes the specific hydrofoil being modeled, including design considerations. The document outlines the extensive meshing trials conducted to generate the computational mesh for CFD analysis. It discusses important considerations for setting up the fluid solver, including initialization parameters, turbulence models, and mesh quality. Results are then presented for two test cases of the hydrofoil design, analyzing lift and drag forces. The report concludes with notes on further optimizing the hydrofoil design based on the CFD results.
Analysis Of Owl-Like Airfoil Aerodynamics At Low Reynolds Number FlowKelly Lipiec
The document analyzes the aerodynamic characteristics of an owl-like airfoil at a low Reynolds number of 23,000 using computational fluid dynamics simulations. It finds that the owl-like airfoil achieves higher lift coefficients and lift-to-drag ratios than the Ishii airfoil, which was designed for high performance at low Reynolds numbers. The owl-like airfoil's round leading edge, flat upper surface, and deeply concaved lower surface contribute to lift enhancement through mechanisms like a suction peak and laminar separation bubble near the leading edge. However, the owl-like airfoil does not achieve its minimum drag coefficient at zero lift, unlike the Ishii airfoil. The document aims to provide insights that can
Strategic design of aircraft wings have evolved over time for maximum fuel efficiency. One of such ideas involves winglet which has been known
to reduce turbulence at the tip of the wings. This study intends to investigate the
differences in drag and lift forces generated at aeroplane wings with and without winglet at cruising speed using FEM. Simulations were performed in the
SST turbulence model of CFD and the results are compared to that of the experimental and theoretical models. The simulation showed that the lift increased
by 26.0% and the drag decreased by 74.6% for the winglet at cruising speed.
This document describes an ornithopter project created by a group of students. It provides background on ornithopters, including that they are aircraft that fly by flapping wings like birds. It discusses the aerodynamics of flapping flight and how designers seek to mimic birds and insects. The document also outlines the history of ornithopters, current projects worldwide, and details of the students' model including its components, mechanism, and potential applications such as surveillance.
- The document is a seminar paper on aircraft drag reduction techniques presented by Dhanashree M. Waghmare and guided by Prof. V. A. Yevalikar. It includes sections on literature review, aims and objectives, introduction to basic aerodynamic principles, aircraft wing terminology, forces on aircraft, types of drag, factors affecting drag, and methods to reduce drag. The paper discusses drag reduction techniques like increasing wing aspect ratio, wing tip devices, vortex generators, and laminar flow control. It concludes with future areas of research like friction drag reduction at supersonic speeds and circulation control using auxiliary power.
Numerical investigation of fluid flow and aerodynamic performance on a 2D NAC...editorijrei
The performance of an aircraft wing mostly depends on the aerodynamic characteristics i.e. lift force, drag force, pressure distribution, the ratio of lift to drag etc. In this paper, the influence of aerodynamic performance on two dimensional NACA 4412 airfoil is investigated. The computational method consist of steady state, incompressible, finite volume method, spalart-allmaras turbulence model. The flow has been studied with the help of Navier-Stroke and continuity equations. Numerical simulations were performed at Reynolds number (1x106, 2x106, 3x106, and 4x106) at a different angle of attack (00, 30,60, and 90). The results give the satisfactory measure of confidence of fidelity of the simulation. Aerodynamic forces are calculated with different Reynolds number and angle of attack, after analyzing the data it is found that the higher lift coefficient was obtain in Re-4x106 at an angle of attack 9 whereas low drag coefficient obtained in Re-1x106 at AOA-0.
The International Journal of Engineering and Science (IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
This document summarizes the Hess-Smith panel method for analyzing aerodynamic forces on airfoils. It begins with background on aerodynamics and the different types of air flow. It then describes the 2D Hess-Smith panel method, which involves discretizing an airfoil shape into panels and calculating source strengths to model the air flow. The document provides the theoretical equations for calculating velocity potential and solving for source strengths. It concludes by explaining the Python code used to implement the 2D source panel method on a NACA 0010 airfoil.
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Optimisation of the design of uav wing j.alexandersathyabama
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Airfoil Terminology, Its Theory and Variations As Well As Relations with Its Operational Lift Force and Drag Force in Ambient Conditions
1. ISSN 2393-8471
International Journal of Recent Research in Civil and Mechanical Engineering (IJRRCME)
Vol. 2, Issue 1, pp: (268-277), Month: April 2015 – September 2015, Available at: www.paperpublications.org
Page | 268
Paper Publications
Airfoil Terminology, Its Theory and Variations
As Well As Relations with Its Operational Lift
Force and Drag Force in Ambient Conditions
1
Dr V.N. Bartaria, 2
Shivani Sharma
1
H.O.D Mechanical engineering LNCT Bhopal, India
2
B.E. Mechanical engineering Pursuing M.tech
Abstract: It is a fact of common experience that a body in motion through a fluid experiences a resultant force
which, in most cases is mainly a resistance to the motion. A class of body exists, However for which the component
of the resultant force normal to the direction to the motion is many time greater than the component resisting the
motion, and the possibility of the flight of an airplane depends on the use of the body of this class for wing
structure. Airfoil is such an aerodynamic shape that when it moves through air, the air is split and passes above
and below the wing. The wing’s upper surface is shaped so the air rushing over the top speeds up and stretches out.
This decreases the air pressure above the wing. The air flowing below the wing moves in a comparatively
straighter line, so its speed and air pressure remains the same. Since high air pressure always moves toward low
air pressure, the air below the wing pushes upward toward the air above the wing. The wing is in the middle, and
the whole wing is “lifted.” The faster an airplane moves, the more lift there is. And when the force of lift is greater
than the force of gravity, the airplane is able to fly.
Keywords: Airfoil, lift force, Drag Force.
1. INTRODUCTION
An airfoil-shaped body moved through a fluid produces an aerodynamic force. The component of this force perpendicular
to the direction of motion is called lift. The component parallel to the direction of motion is called drag. Subsonic flight
airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric
curvature of upper and lower surfaces. Foils of similar function designed with water as the working fluid are called
hydrofoils.
The lift on an airfoil is primarily the result of its angle of attack and shape. When oriented at a suitable angle, the airfoil
deflects the oncoming air, resulting in a force on the airfoil in the direction opposite to the deflection.
This force is known as aerodynamic force and can be resolved into two components: lift and drag. Most foil shapes
require a positive angle of attack to generate lift, but cambered airfoils can generate lift at zero angle of attack.
This “turning” of the air in the vicinity of the airfoil creates curved streamlines which results in lower pressure on one side
and higher pressure on the other. This pressure difference is accompanied by a velocity difference, via Bernoulli’s
principle, so the resulting flow field about the airfoil has a higher average velocity on the upper surface than on the lower
surface. The lift force can be related directly to the average top/bottom velocity difference without computing the pressure
by using the concept of circulation and the Kutta-Joukowski theorem.
2. ISSN 2393-8471
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Figure: 1 Examples of airfoils in nature and within various vehicles. Though not strictly an airfoil, the dolphin flipper obeys
the same principles in a different fluid medium
Figure: 2 Streamlines around a NACA 0012 airfoil at moderate angle of attack
3. ISSN 2393-8471
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Figure: 3 Lift and Drag curves for a typical airfoil
2. THEORY OF AIRFOIL
Thin airfoil theory is a simple theory of airfoils that relates angle of attack to lift for incompressible, in viscid flows. It
was devised by German-American mathematician Max Munk and further refined by British aerodynamicist Hermann
Glauert and others in the 1920s. The theory idealizes the flow around an airfoil as two dimensional flows around a thin
airfoil. It can be imagined as addressing an airfoil of zero thickness and infinite wingspan.
Thin airfoil theory was particularly notable in its day because it provided a sound theoretical basis for the following
important properties of airfoils in two-dimensional Flow:
(1) On a symmetric airfoil, the center of pressure and Aerodynamic center lies exactly one quarter of the chord behind the
leading edge
(2) On a cambered airfoil, the aerodynamic center lies exactly One quarter of the chord behind the leading edge
(3) The slope of the lift coefficient versus angle of attack Line is 2π units per radian As a consequence of (3), the section
lift coefficient of a Symmetric airfoil of infinite wingspan is:
4. ISSN 2393-8471
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= 2πα
Where is the section lift coefficient α is the angle of attack in radians, measured Relative to the chord line.
(The above expression is also applicable to a cambered Airfoil where α is the angle of attack measured relative to The
zero-lift line instead of the chord line.)
Also as a consequence of (3), the section lift coefficient Of a cambered airfoil of infinite wingspan is:
Thin airfoil theory does not account for the stall of the Airfoil, which usually occurs at an angle of attack between 10°
and 15° for typical airfoils.
4 Derivation of thin airfoil theory: The airfoil is modeled as a thin lifting mean-line (camber line). The mean-line, y(x), is
considered to produce a distribution of vorticity (s) along the line, s. By the
Kutta condition, the vorticity is zero at the trailing edge. Since the airfoil is thin, x (chord position) can be used instead of
s, and all angles can be approximated as small. From the Biot–Savart law, this vorticity produces a flow
field w(x) where
Where x is the location where induced velocity is produced, x′ is the location of the vortex element producing the velocity
and c is the chord length of the airfoil.
Since there is no flow normal to the curved surface of the airfoil, w(x) balances that from the component of main flow V ,
which is locally normal to the plate – the main flow is locally inclined to the plate by an angle α-dy/dx. That is:
3. 4 DERIVATION OF THIN AIRFOIL THEORY
Figure: 4. 4 Derivation of thin airfoil theory
5. ISSN 2393-8471
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From top to bottom:
• Laminar flow airfoil for a RC park flyer
• Laminar flow airfoil for a RC pylon racer
• Laminar flow airfoil for a manned propeller aircraft
• Laminar flow at a jet airliner airfoil
• Stable airfoil used for flying wings
• Aft loaded airfoil allowing for a large main spar and late stall
• Transonic supercritical airfoil
• Supersonic leading edge airfoil
Colors:
Black = laminar flow,
Red = turbulent flow,
Grey = subsonic stream,
Blue = supersonic flow volume
This integral equation can by solved for (x) , after replacing x by
as a Fourier series in with a modified lead
term
That is
(These terms are known as the Glauert integral). The coefficients are given by
By the Kutta–Joukowski theorem, the total lift force F is Proportional to
6. ISSN 2393-8471
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and its moment M about the leading edge to
The calculated Lift coefficient depends only on the first two terms of the Fourier series, as
The moment M about the leading edge depends only on A0;A1 and A2 , as
The moment about the 1/4 chord point will thus be,
From this it follows that the center of pressure is aft of the 'quarter-chord' point 0.25 c, by
The aerodynamic center, AC, is at the quarter-chord point. The AC is where the pitching moment M' does
not vary with angle of attack, i.e.,
Coefficient of Drag and Coefficient of Lift:
The drag equation,
Fd = rn Cd
so co efficient of drag is given by the, Cd= 2Fd / rn^2A
is essentially a statement that the drag force on any object is proportional to the density of the fluid and proportional to the
square of the relative speed between the object and the fluid. In fluid dynamics the cd is a dimensionless quantity that is
used to quantify the drag or resistance of an object in a fluid environment such as air or water. It is used in the drag
equation where a lower drag coefficient indicates the object will have less aerodynamic or drag. The drag coefficients
always associated with a particular surface area. The drag coefficient of any object comprises the effects of the two basic
contributors to fluid dynamics drag: skin friction and from drag. The drag coefficient of a lifting airfoil or hydrofoil also
includes the effects of lift induced drag. The drag coefficient of a complete structure such as an aircraft also includes the
effects of interference drag. The overall drag coefficient defined in the usual manner is The reference area depends on
what type of drag coefficient is being measured. For automobiles and many other objects, the reference area is the
7. ISSN 2393-8471
International Journal of Recent Research in Civil and Mechanical Engineering (IJRRCME)
Vol. 2, Issue 1, pp: (268-277), Month: April 2015 – September 2015, Available at: www.paperpublications.org
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projected frontal area of the vehicle. This may not necessarily be the cross sectional area of the vehicle, depending on
where the cross section is taken and for an airfoil the surface area is a plane form area. The lift equation,
L = rn A CL
so coefficient of lift is given by the,
CL = 2L/rn S =L/qs
A fluid flowing past the surface of a body exerts a force on it. Lift is the component of this force that is perpendicular to
the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the
flow direction. If the fluid is air, the force is called an aerodynamic force.
Relationship between angle of attack, coefficient of drag and coefficient of lift:
Figure 5: Relationship of Different Coefficients
The lift coefficient of a fixed-wing aircraft varies with angle of attack. Increasing angle of attack is associated with
increasing lift coefficient up to the maximum lift coefficient, after which lift coefficient decreases. As the angle of attack
of a fixed-wing aircraft increases, separation of the airflow from the upper surface of the wing becomes more pronounced,
leading to a reduction in the rate of increase of the lift coefficient. The figure shows a typical curve for a cambered
straight wing. A symmetrical wing has zero lift at 0 degrees angle of attack. The lift curve is also influenced by wing
platform. A swept wing has a lower, flatter curve with a higher critical angle. Identically the value of drag coefficient is
zero at the zero AOA and it increase slowly till the stall condition and at the time of stall as well as after stall it increase
readily as shown in figure 3. Particular airspeed, the airspeed at which the aircraft stalls varies with the weight of the
aircraft, the load factor, the center of gravity of the aircraft and other factors. However the aircraft always stalls at the
same critical angle of attack. The critical or stalling angle of attack is typically around 15° for many airfoils.
The process of airfoil design proceeds from a knowledge of the boundary layer properties and the relation between
geometry and pressure distribution. The goal of an airfoil design varies. Some airfoils are designed to produce low drag
(and may not be required to generate lift at all.) Some sections may need to produce low drag while producing a given
amount of lift. In some cases, the drag doesn't really matter - it is maximum lift that is important. The section may be
required to achieve this performance with a constraint on thickness, or pitching moment, or off-design performance, or
other unusual constraints. Some of these are discussed further in the section on previous section of historical examples.
One approach to airfoil design is to use an airfoil that was already designed by someone who knew what he or she was
doing. This "design by authority" works well when the goals of a particular design problem happen to coincide with the
goals of the original airfoil design. This is rarely the case, although sometimes existing airfoils are good enough. In these
cases, airfoils may be chosen from catalogs such as Abbott and von Doenhoff's Theory of Wing Sections, Althaus' and
Wortmann's Stuttgarter Profilkatalog, Althaus' Low Reynolds Number Airfoil catalog, or Selig's "Airfoils at Low
Speeds". The advantage to this approach is that there is test data available. No surprises, such as a unexpected early stall,
are likely. On the other hand, available tools are now sufficiently refined that one can be reasonably sure that the predicted
8. ISSN 2393-8471
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performance can be achieved. The use of "designer airfoils" specifically tailored to the needs of a given project is now
very common. This section of the notes deals with the process of custom airfoil design. Methods for airfoil design can be
classified into two categories: direct and inverse design.
Contours of Static pressure over NACA 0012 Airfoil:
The static pressure of the air is simply the weight per unit area of the air above the level under consideration. For instance,
the weight of the column of air with a cross-sectional area of 1 ft-square and extending upward from sea level through the
atmosphere is 2116 lb. The sea level static level is therefore 2116 psf. Static pressure is decrease as altitude is increased
because there is less air weight above. At 18,000 ft altitude the static pressure is about half that at sea level. The
amalgamation of static pressure and dynamic pressure is known as total pressure. For and angle of attack is zero degree
we obtain that the contours of static pressure over an aerofoil is symmetrical for above and lower sections and the
stagnation point is exactly at the nose of an aerofoil. Hence there is no pressure different Created between two faces of
aerofoil at zero degree of an angle of attack.
Figure 6: Contours of static pressure over NACA 0012 airfoil at 0 degree of AOA
Figure 7: Contours of static pressure over NACA 0012 airfoil at 6 degree of AOA
9. ISSN 2393-8471
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For an angle of attack of 6 degrees, we see that the flow has a stagnation point just under the leading edge and hence
producing lift as there is a low pressure region on the upper surface of the foil as shown in Figure 6. We can also observe
that Bernoulli’s principle is holding true; the velocity is high (denoted by the red contours) at the low pressure region and
vice‐versa. There is a region of high pressure at the leading edge (stagnation point) and region of low pressure on the
upper surface of airfoil.
Contours of Velocity magnitude over NACA0012 airfoil:
As shown in figure 7 and 8 at the 0 degree of AOA the velocity contours are same as symmetrical and at 6 degree of AOA
the stagnation point is slightly shift towards the trailing edge via bottom surface hence it will create low velocity region at
lower side of the airfoil and higher velocity acceleration region at the upper side of the airfoil and according to principle
of Bernoulli's upper surface will gain low pressure and lower surface will gain higher pressure. Hence value of coefficient
of lift will increase and coefficient of drag will also increase but the increasing in drag is low compare to increasing in lift
force. In a symmetrical airfoil at no incidence, the distribution of velocity and thus the pressures along both surfaces
would have been exactly the same, canceling each other to a resulting total lift force of zero
Figure 8: Contours of velocity magnitude over NACA 0012 airfoil at 0 degree of AOA
4. RESULTANT VALUES AND GRAPHS
Figure 9: Graph of coefficient of drag at zero degree AOA
10. ISSN 2393-8471
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Figure 10: Graph of coefficient of drag at zero degree AOA
5. CONCLUSION
Based on the CFD analysis of the flow over NACA 0012 air foil we can conclude that at the zero degree of AOA there is
no lift force generated and if we want to increase amount of lift force and value of lift coefficient then we have to increase
the value of AOA. By doing that obviously amount of drag force and value of drag coefficient also increased but the
amount of increment in drag force and drag coefficient is quite lower compare to lift force. Here we understand the all
about the airfoil and from have some analysis we got some suitable result.
REFERENCES
[1] V. P. Gountis and A. G. Bakirtzis, “Bidding strategies for electricity producers in a competitive electricity
marketplace,” IEEE Trans. Power System, vol. 19, no. 1, pp. 356–365, Feb. 2004.
[2] J. Clerk Maxwell, “A Treatise on Electricity and Magnetism”, 3rd ed., vol. 2. Oxford: Clarendon, 1892, pp.68–73.
[3] R. Benato and A. Paolucci, EHV AC Undergrounding Electrical Power. Performance and Planning. New York:
Springer, 2010.
[4] Angus DC, Linde-Zwirble WT, Lidicker J et al (2001) Epidemiology of severe sepsis in the United States: analysis
of incidence, outcome, and associated costs of care. Crit Care Med 29:1303–1310.
[5] Levy MM, Dellinger RP, Townsend SR, and Surviving Sepsis Campaign et al (2010) The Surviving Sepsis
Campaign: results of an international guideline-based performance improvement program targeting severe sepsis.
Crit Care Med 38:367–374.
[6] CIGRÉ Tech. Brochure # 379, “Update of service experience of HV underground and submarine cable systems,”
2009.
[7] E. E. Reber, R. L. Mitchell, and C. J. Carter, "Oxygen absorption in the Earth's atmosphere," Aerospace Corp., Los
Angeles, CA, Tech. Rep. TR-0200 (4230-46)-3, Nov. 1968.
[8] Wikipedia