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Aerodynamics Aerodynamics Lecture 1 Chapter 1

Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

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Page 1: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

AerodynamicsAerodynamics

Lecture 1

Chapter 1

Page 2: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

What is Aerodynamics?

How does the text define Aerodynamics?

Page 3: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Aerodynamics defined-

• Is the science that deals with the motion of air and the forces on bodies moving through the air.

• The term aerodynamics implies the explanation of why and how airplanes fly.

Page 4: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Why do we need Aerodynamics?

• Pilots, Technicians, and others with an interest in aviation have a need to understand the behavior of the air and its effect on the airplane.

Page 5: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Chapter 1

History of Flight

Page 6: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Greek Mythology

• The story of Daedalus and his son Icarus.– They utilized flight as a means of escape from

the island of Crete where they were imprisoned.– Icarus flew too close to the sun and the heat

melted the wax in his wings.– He fell to the sea and suffered one of the first

fatal crashes in history.

Page 7: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

What famous artist dreamed of flight?

He cut off his ear.

Page 8: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Leonardo da Vinci

• He was obsessed with the idea of transforming the muscle-power of man into lift and thrust through a flapping device called the ornithopter. (figure 1-3 p. 3)

Page 9: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Aerostatics

• How does a balloon fly?– The buoyancy principle discovered by

Archimedes.– The pressure in any fluid, liquid, or gas,

increases in depth. – Explain the phrase,” high to low look out

below?”

Page 10: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Example

• A small chunk of fluid within a larger container of fluid.

– The pressure on the bottom of the surface is greater than the pressure on the top of the surface.

– If the chunk of fluid had no weight , it would be pushed upward by the increased pressure of the bottom; however, the weight of this chunk of fluid added to the pressure force on the top surface balances out the increased pressure.(Static or still)

Page 11: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Example

• Now suppose that this chunk of fluid is replaced by a container filled with a fluid lighter than the surrounding fluid.

• The total weight of the container and the fluid inside it must be considered.

– This total weight must be less than the weight of the amount of fluid displaces in order for it to rise.

Page 12: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Balloons

• The previous example is the principle that causes a balloon to ascend.

– Heated or lighter-than-air gas is placed inside the balloon.

– When the resulting weight of the balloon and the gas inside it is less than the surrounding air, the balloon ascends.

Page 13: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Why does the balloon not rise to the top of the atmosphere?

• The balloon, which has a gas of a certain density inside, rising in the atmosphere.

• Eventually it will reach an altitude where the density of the outside of the balloon and the density inside the balloon are the same.– At this point the forces are again in balance and the

pressure is not great enough to push the balloon upward. (figure 1-7, p.7)

Page 14: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Balloons

• Balloons are referred to as aerostatic vehicles, which means that they will lift in a static air mass.

• The balloon has no mechanism to move horizontally in this air mass. (only velocity and wind direction)

Page 15: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Joseph & Etienne Montgolfier

• The brothers designed and built the first hot air balloon in France in June of 1783.(figure 1-4,p. 4)

• They did not know what caused their balloon to ascend. (they thought burning wood released some unknown gas that mysteriously caused objects to rise.)

• The principles of lighter than air soon became known and both hot-air and hydrogen-filled balloon flights were launched before the end of that year.

Page 16: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Hot Air Vs. Lighter than Air Gas

• Hot air may be used at lower altitudes, however, at higher altitudes the temperature decreases causing the hot air to cool.

• Lighter than Air Gas is used in high altitude flight.

Page 17: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Compressibility

• Remember that air is compressible unlike water.

• Air is compressed by its own weight.

• Because all of the air is above the surface, the highest compression and highest density altitude occurs at the surface.

• As you go up in altitude, there is less air above causing the compression at that altitude; therefore the air is less dense.

Page 18: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Airship

• A lighter-than air craft with propulsive capability.

• Fuel is required only to provide propulsion and not lift, as it is with other types of aircraft.

Page 19: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Heavier-Than Air Flight

• Men attempted to emulate the birds, wing flapping and gliding.– One of the first persons to recognize the fixed-

wing mode of flight was an English nobleman, Sir George Cayley.

– He was the first to recognize the importance of stability and control in an aircraft and designed his tail sections accordingly.

Page 20: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Sir George Cayley

• In 1853 Cayley designed and built a human-carrying glider.– His coachman was pressed into service as the

pilot and made the 1st manned flight of a heavier-than air craft in history.

– The coachman promptly resigned after the experiment.

– Cayley’s work was published however it was not recognized until recently.

Page 21: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Otto Lilienthal

• A German engineer that approached the idea of flight with scientific reasoning and analysis.

• Lilienthal made many successful glider flights but crashed before he was able to achieve his ultimate goal of powered flight.– Figure 1-8 on p. 9 shows Lilienthal’s design.

Page 22: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Octave Chanute

• A Chicago engineer, was experimenting with gliders around the same time as Lilenthal.

• Chanute was also scientific in his approach and contributed significantly to the structural soundness of aircraft design.– Figure 1-9, p. 9 shows Chanute experimenting with

gliders.

Page 23: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

The men who recognized all of the problems involved with

flight?

They worked in a bicycle shop!

Page 24: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Wilbur & Orville Wright

• Their procedure was methodical and scientific in the approach.

• They studied the successes and failures of others especially Lilenthal and Chanute.

• They tackled one problem at a time: construction techniques, devising controls, teaching themselves to fly, & increasing the efficiency of design.

Page 25: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

December 17, 1903

• World’s First Sustained, Controlled, and Powered Flight!

– Where?– Who was the pilot?

• How did they decide who would pilot?

Page 26: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

The Science of Aerodynamics

• Gliders are ______________ machines.

• The study of moving air and the forces that it produces is referred to as ____________, meaning literally, “air in motion”

• Aerostatic means _____ ____ ______.

Page 27: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Classical Theory of Flight

• Scientists began around 1910 to look into the physical principles of winged flight including behavior of wings & airfoils.

• Frederick Lancaster in England

• Ludwig Prandtl in Germany

• Joukowsky in Russia– These men were scientists with the intent to explain

physical behavior; not interested in developing aircraft.

Page 28: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Quiz on Lecture 1

Please take out a sheet of paper. Include today’s date and your name.

Page 29: Aerodynamics Lecture 1 Chapter 1. What is Aerodynamics? How does the text define Aerodynamics?

Quiz on Lecture 1

• Please explain how a balloon ascends to 10,000 feet and remains at this altitude?

• How did Cayley’s approach to achieving manned flight differ from Da Vinci’s?

• What was the key to the Wright brother’s success?

• What did scientists like Lancaster, Prandtl,& Jaoukowsky contribute to the development of the first airplane?

• Why do we need to study aerodynamics?