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AER 101 Introduction to Aeronautics Instructor : Prof. Dr. Galal Bahgat Salem. Textbook : John D. Anderson, Jr, Introduction to Flight , 4 th Edition , 2000 . Term Work : 25 +25 = 50 Marks Final Exam: 50 +50 = 100 Marks. AER 101 A Introduction to Aeronautics ( 2 + 1 ). History of Flight
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AER 101 Introduction to AeronauticsInstructor : Prof. Dr. Galal Bahgat Salem Textbook : John D. Anderson, Jr, Introduction to Flight , 4th Edition , 2000 . Term Work : 25 +25 = 50 Marks Final Exam: 50 +50 = 100 Marks Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
AER 101 A Introduction to Aeronautics ( 2 + 1 ) • History of Flight • Nature of Aerodynamic Forces • Airplane components and Configurations • Scope of Aeronautical Engineering • Fluid Properties and Characteristics • Atmosphere • Basic Aerodynamics : Kinematics, Continuity and Bernoulli’s Equations, Boundary Layer Concept, Skin Friction, Pressure Drag, Flow Separation, Streamlining Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
AER 101B Introduction to Aeronautics ( 2 + 1 ) • Geometric and Aerodynamic Characteristics of Airfoils • Dimensional Analysis and Aerodynamic Force Coefficients • Elements of Airplane Performance: Drag-Speed Curve, Cruising Flight Performance, Climbing Performance, Gliding Performance • Elements of Propulsion: Propellers, Piston Engines, Reaction Principle, Jet Engines, Rocket Motors • Elements of Airplane Stability and Control Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Chapter 1History Of Flight What is Flight ? ■ Flight is a motion in air free from ground topography ■ It is a high-speed motion through a low-resistance ( low density ) medium which is air N.B. Compare flight in air, having a density of 1.225 Kg/m3, with shipping in water of density 1000 Kg/m3 Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Short History of Flight1. Imitating Birds • People attempting to fly by using artificial wings strapped to their arms and-or legs • The flapping of wings generate lift • The Greek myth of Daedalus and his son Icarus imprisoned on the island of Crete in the Mediterranean Sea illustrates man’s flight • The idea of strapping a pair of wings to arms fell out of favor • It was replaced by concept of wings flapped up and down by various mechanical devices, Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Powered by human arm, leg, or body movement • These are called Ornithopters • Ornithopters first designed by Leonardo da Vinci ( 1452-1519 ) Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Leonardo da Vinci Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Why Don’t Ornithopters Work? • G. A. Borelli (1680 ) realized the fact that ( power/weight) ratio of a man is much less than that of bird • Hence man will never be able to fly like a bird, by his own power only 2. Lighter-than-Air Balloons[Unpowered Flight] ● Firstly hot air balloons discovered by the Montgolfier Brothers in France (1783) Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Later on gas balloons of Hydrogen/Helium were used by Charles • Charles found that ballooning is based on Archimedes principle of buoyancy Manned Balloon • Unmanned Balloon Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
3. Lighter-than-Air Dirigibles (Airships)[Powered] ●Firstly invented by Count von Zeppelin in Germany (1900) ●They are more rigid (the first airframe) than balloons, controlled and directed (using stabilizing surfaces) and propeller droved ●Large bags of gas inside the rigid airframe ●Count von Zeppelin (1929), flew around the world in 21 days ●Hydrogen fired in “Hindenburg” dirigible in 1937 Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
4.Sir George Cayley (1799) ●First pioneered the concept for the modern airplane configuration in 1799 - Fixed wings, tail, fuselage - Separate mechanism for propulsion “separation of lift and propulsion” ● Recognized that the function of thrust was to overcome aerodynamic drag ●Drew the first lift-drag vector diagram in the history N.B. Beforethis time flapping wings were supposed to provide both lift and propulsion Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Lift Resultant Aerodynamic Force Thrust Drag Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
5.Heavier-than-Air Unpowered Gliders (Sailplanes) • Gliders first designed and flew by Otto Lilienthal, a German mechanical engineer, in 1891 • Lilienthal is known as the glider’s man • Gliders characterized by un-sustained flight Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
He died in 1896, after stalling a glider he was flying Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
6.Heavier-than-Air Powered Airplanes • Samuel P. Langleywas contracted to build a flying machine for the U.S. government • Began a series of aerodynamic experiments in 1887 • Successful in flying several small scale, unmanned, powered aircraft, which he called aerodromes • These were the first steam-powered, heavier-than-airmachines to successfully fly • Langley’s attempt to build a manned aerodrome failed • Lunched and crashed on Oct. 7 and December 8, 1903 Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Langley’s aerodrome shortly after launch Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
The Wright Brothers • Wright brothers (Orville&Wilbur) were the inventors of the first practical manned flight on 17 Dec.,1903 (Flyer I ) • It was a strut-and-wire biplane configuration • Propulsion was achieved by a four-cylinder in-line engine designed and built by Orville Wright • It produced close to 12 hp and weighed 140 Ibs • It drove two propellers via a bicycle-like chain loop Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
The control feature of Wright flyer is one of the basic reasons for its success • Flyer I had a wing span of 12 m , flew a distance of 256 m, and lasting 59 sec Wright Flyer Engine Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Wright Flyer engine Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
■Hydrostatics of Lighter-than-Air Flight • The lifting force is the buoyancy force • The basic laws of hydrostatics (fluid at rest) are: a- fluid pressure p is uniform in horizontal planes, as well as the density b- p varies only with height z according to the Hydrostatic equation z datum Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
dp/dz = -ρg Integrating, in case of constant density: p + ρ g z = constant This is the hydrostatic equation non-uniform p distribution on a body immersed in a fluid at rest p z B p + ρ g z Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
The resultant fluid-pressure force is called the buoyancy force B, acting vertically upward, and equals to the weight of the displaced fluid • B = ρ g V where ρdensity of fluid g acceleration of gravity V volume of immersed body N.B. The basis of Heavier-than-air Flight will discussed later Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Anatomy OF THE AIRPLANE■The Main Components of the Airplane Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
The basic airplane components include: fuselage, wing, tail assembly, control surfaces, landing gear, and power plant(s) 1.The Fuselage ♦ It carries the payload. ♦ It is the central structural member of the airframe to which other members are attached. ♦ It is generally streamlined to reduce drag. ♦ Designs vary with the mission to be performed, as illustrated in figure Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
2.The Wing ● It generates the lift force. • It includes the flaps for lift augmentation during landing and takeoff, and ailerons for banking the airplane during turning. • The wing cross-section is called Airfoil • The airfoil shape, wing planform shape, and placement of the wing on the fuselage depend upon the airplane mission. • The figure illustrates wing shapes and placements Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
3.Tail Assembly and Control Surfaces • The tail assembly (empennage) represents the collection of structures at the rear of the airplane • The tail assembly consists of: 1- The vertical stabilizer (fin) and rudder which provide directional stability in yaw 2-The horizontal stabilizer and elevator which provide longitudinal stability in pitch ● The figure illustrates different forms of tail assembly Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
4.Landing Gear • The landing gear (undercarriage) supports the airplane while it is at rest on the ground and during the takeoff and landing • The gear may be fixed or retractable • The wheels are attached to shock-absorbing struts that use oil or air to cushion the blow of landing • Special types of landing gear include skids for snow and floats for water • For carrier landings, arrester hooks are used Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
4.Power Plants • Power plants used to produce the thrust force necessary to propel the airplane to overcome the drag • The power plant consists of the engine (and propeller, if present) and accessories • The main engine types are: -Reciprocating (or piston type) -Reaction engines such as turbojet, turbofan, turboprop, ram jet, pulse jet, and rocket engine The figure shows several some of engine placements Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
■The Aircraft Structure • The figure shows a cutaway drawing of an aircraft structure Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Basic Elements of Aircraft Structure ■The wing Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Wing structure basically same in all aircraft types • Modern aircrafts have all metal and composite material wings but many older had wood and fabric wings • The wing is a framework composed of spars, ribs and (possibly) stringers (see figure) • Spars are the main members of the wing. They extended lengthwise of the wing (crosswise of fuselage) • Most wing structures have two spars, the front spar and the rear spar Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
Front spar near the leading edge, while the rear spar at about two-thirds the distance to the trailing edge • The ribs are the parts of the wing which support the covering and provide the airfoil shape • A skin covers the wing framework Prof. Galal Bahgat Salem Aerospace Dept., Cairo University
■The Fuselage Prof. Galal Bahgat Salem Aerospace Dept., Cairo University