1. The Physics of Flight

2. Myths and Legends of Flight Icarus and Daedalus –Daedalus- engineer imprisoned by King Minos. –With his son, Icarus, he made wings of wax and feathers. –Daedalus flew successfully from Crete to Naples –Icarus, flew too near to the sun. The wings of wax melted and Icarus fell to his death in the ocean. Pegasus Pegasus –Mythological Winged horse

3. Ancient Dreamers Legends of flight attempts date to 2000 B.C. Legends of flight attempts date to 2000 B.C. –Many believed flying was for the mythical gods –Others tried to copy bird flight-unsuccessfully Chinese invented kites about 200 - 500 B.C. Chinese invented kites about 200 - 500 B.C. –17 th century A.D. kites carried soldiers aloft –WWI – Kites were used to spy on enemies –Buddhists Monks used them to “avert evil spirits and insure rich harvests”

5. Ancient Dreamers Leonardo da Vinci Leonardo da Vinci Engineer, Scientist, Inventor and Artist Engineer, Scientist, Inventor and Artist Italian artist and scientist Leonardo da Vinci (1452- 1519) gathered data on the flight of birds and bats To develop concepts of the propeller, the parachute, and heavier-than-air craft.

6. Leonardo da Vinci Leonardo da Vinci, 15 th century Italian artist Leonardo da Vinci, 15 th century Italian artist –First recorded scientific study of –First recorded scientific study of aeronautics –Experimented to prove feasibility of mechanical flight –Drew approximately 500 sketches and plans to construct flying machines

7. Other Da Vinci Inventions Bicycle Bicycle Armored “Car” Armored “Car” Giant Crossbow Giant Crossbow Boats Boats Water Skis Water Skis Eight Barreled Machine Gun Eight Barreled Machine Gun Anemometer – wind speed Helicopter – “Arial Screw” Helicopter – “Arial Screw” More Accurate Clock More Accurate Clock Robotic Knight Robotic Knight Scuba Gear Scuba Gear Revolving Bridge Revolving Bridge

9. The Quest for Flight By 17th Century, ancient ideas inspired scientific theories and experiments By 17th Century, ancient ideas inspired scientific theories and experiments 1783 – Studies of the atmosphere and the discovery of gases and properties led to balloon experiments 1783 – Studies of the atmosphere and the discovery of gases and properties led to balloon experiments –First balloon - silk balloon with a basket –First passengers - a sheep, a rooster and a duck –Rose up to 6000 feet, traveled for over 1 mile Glider flying increased the understanding of flight forces, wing geometry & controls Glider flying increased the understanding of flight forces, wing geometry & controls

10. Understanding Flight How do Birds Fly??? How do Birds Fly??? How do Birds Fly??? How do Birds Fly??? –Wing Design –Hollow Bones –Large Lungs –Air Sacs – Strong Muscles

11. Aerodynamics? Aero – means Air Dynamics – means Motion Aerodynamics – the study of air in motion Important Point: Air is “Viscous” Uh, that means it’s Sticky

12. Definition: Aerodynamics Aerodynamics A branch of fluid mechanics that deals with the motion of air and other gaseous fluids

13. Airfoil A structure with curved surfaces A structure with curved surfaces – designed to give the best ratio of lift to drag in flight –The basic form of the wings, fins, and horizontal stabilizer of most aircraft.

14. Forces and Vectors A force may be thought of as a push or pull in a specific direction. A force is a vector quantity so a force has both a magnitude and a direction. When describing forces, we have to specify both the magnitude and the direction.

15. Airplane Parts Fuselage (Body) Wing Horizontal Stabilizer Vertical Stabilizer Empennage (Tail) Engine

16. Bernoulli’s Principle As the velocity of a fluid increases the pressure exerted by the fluid decreases. As the velocity of a fluid increases the pressure exerted by the fluid decreases.

17. Air Flow Past a Wing The air speed is greater over the upper surface and the air pressure is lower there and the wing is lifted The air speed is greater over the upper surface and the air pressure is lower there and the wing is lifted When the wing is angled upward, air deflected from its lower surface provides additional lift. When the wing is angled upward, air deflected from its lower surface provides additional lift. If the angle is too great, turbulence reduces lift and increases drag. If the angle is too great, turbulence reduces lift and increases drag.

18. Powered Flight Breakthrough Experiments showed basic ingredients of flight are: sufficient power, lift, control Experiments showed basic ingredients of flight are: sufficient power, lift, control Application of theories of lift and drag to practical use in powered gliders Application of theories of lift and drag to practical use in powered gliders Progress (and a conventional designs) came with lighter materials and drag reduction Progress (and a conventional designs) came with lighter materials and drag reduction

19. Breakthrough Sir Hiram Maxim Sir Hiram Maxim –power, lift, control Wright brothers Wright brothers Glen Curtiss Glen Curtiss –Improved designs, promoted aviation December 17, 1903, near Kitty Hawk, North Carolina, Wilbur and Orville Wright made the world's first successful powered, free, controlled, sustained flights in a heavier-than-air craft. The Main Events

20. World War I War speeds up technology development War speeds up technology development Airplane speed and loads increased Airplane speed and loads increased Large manufacturing base developed Large manufacturing base developed The Main Events

21. After the War Veteran pilots kept interest alive Veteran pilots kept interest alive Commercial aviation catches on Commercial aviation catches on Dramatic design advances Dramatic design advances Beginning of rocket flight Beginning of rocket flight Invention of the jet engine Invention of the jet engine

22. Four Forces of Flight Lift Lift Weight Weight Thrust Thrust Drag Drag Source: NASA Glen Research Center

23. 4 Forces of Flight

24. Weight Center of Gravity (CG)

25. Drag Newton’s 1 st Law Applies

26. Thrust Newton’s 3 rd Law Applies

27. Lift Newton’s 3 rd Law Applies Weight Lift Thrust Drag

28. Think About It It’s “Tug-a-War” The motion of the airplane through the air depends on the relative strength and direction of the forces we’ve discussed. If the 4 forces are balanced, the aircraft cruises at constant velocity and altitude. If the forces are unbalanced, the aircraft accelerates in the direction of the largest force.

30. Lift Lift is an aerodynamic force Lift is an aerodynamic force Lift must exceed weight for flight Lift must exceed weight for flight Generated by motion of aircraft through air Generated by motion of aircraft through air Created by the effects of airflow past wing Created by the effects of airflow past wing The top of an airplane wing is curved, so that air has to travel further to reach the trailing end of the wing. Therefore, the air on the underside of the plane is exerting more pressure, causing the plane to lift.

31. Weight Weight is not constant Weight is not constant –varies with passengers, cargo, fuel load –decreases as fuel is consumed or payload off-loaded Direction is constant toward earth’s center Direction is constant toward earth’s center May be assumed concentrated at the center of gravity May be assumed concentrated at the center of gravity

32. Drag An aerodynamic force An aerodynamic force Drag is also called air resistance. the force that pulls the plane backward. Two broad drag classifications Two broad drag classifications –Parasite drag: drag created by airplane design –Induced drag: by-product of lift generation Acts through the center of pressure Acts through the center of pressure

33. Thrust Forward-acting force opposes drag Forward-acting force opposes drag Direction of thrust depends on design Direction of thrust depends on design Propulsion systems produce thrust Propulsion systems produce thrust Equal to drag in straight, constant speed flight Equal to drag in straight, constant speed flight

34. Stability Basics Center of Gravity Center of Gravity Center of Pressure Center of Pressure –Average location of pressure –Changes with plane movement Longitudinal Stability Longitudinal Stability Lateral Stability Lateral Stability Directional Stability Directional Stability

35. Remember: Center of Gravity for People

36. Definition: Aeronautics Aeronautics is the design and construction of Aeronautics is the design and construction of aircraft and aircraft and The theory and practice of aircraft navigation The theory and practice of aircraft navigation

37. Definition: Aerospace Engineering Aerospace engineering is closely allied to aeronautics and aeronautical engineering but Aerospace engineering is closely allied to aeronautics and aeronautical engineering but Includes the study and development of rocket engines, satellites, and spacecraft Includes the study and development of rocket engines, satellites, and spacecraft

38. What’s Next????