ME 480 Introduction To Aerospace: Chapter 2 - PowerPoint Presentation

Slide1

ME 480 Introduction To Aerospace: Chapter 2

Prof. Doug Cairns

Slide2

Forces On a Body

Slide3

Spatial Quantities

pressure, density, temperature, velocity

Slide4

Supersonic flow(oil streak used for visualization)

Slide5

Smoke Injectors to Visualize Streamlines

Slide6

Particles follow Streamlines

Slide7

Basic Parts on an Airplane

Slide8

Basic Controls of an Airplane

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2-9

For the Next Few Slides

Basic Physics of Flight

What’s happening during a flight

Rule of Thumb

airplane

design

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2-10

Basic Forces

Lift

Weight

Drag

Thrust

Trim

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2-11

What’s in Weight?

Lift

Weight

Drag

Thrust

Trim

Payload

Fuel

Airplane

Operating

Empty

Weight (OEW)

Reserves

Operating items

Systems

Propulsion

Landing Gear

Body

Wing & Tails

Food, Supplies

Navigate, control and support life

Generate force to move airplane

Support airplane on the ground

Enclose the payload

Provide lift

Paying Passengers and Cargo

Slide12

2-12

Weight changes during the flight.

Payload

Fuel

Reserves

Operating items

Systems

Propulsion

Landing Gear

Body

Wing & Tails

Food, Supplies

Navigate, control & support life

Generate force to move airplane

Support airplane on the ground

Enclose the payload

Provide lift

Payload

Fuel

Operating empty weight

End of flight

Start of Flight

Burn off fuel

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2-13

Lift

Weight

Drag

Thrust

Trim

How do you make Lift?

Bernoulli:

“The faster the air flows over the surface, the lower the pressure air exerts on the surface.”

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2-14

How to Change Lift

Since Lift is about the same as weight and weight changes, then must be able to change lift.

Increase lift by

increasing the tilt of the wing

increasing the speed of the airplane (actually speed squared)

decreasing the altitude of the airplane above the ground.

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2-15

But there are Limits to Lift

Lift

Airfoil Tilt Angle

“Stall”

The flow no longer can stay attached to the upper surface.

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2-16

Ways around the Limits to Lift

Lift

Airfoil Tilt Angle

“Slats”

“Slats & Flaps”

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2-17

Wings are made up of airfoils

Airfoil

Wing

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2-18

Lift

Weight

Drag

Thrust

Trim

A propeller produces thrust like a wing produces lift except:

The propeller is a wing rotated 90 degrees

The speed over the airfoil comes from rotating the prop.

How to create Thrust

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2-19

How does a jet engine produce thrust?

Propeller (“compressors”)

Propeller (“turbines”)

Fuel Burned

(

Generates

high speed air)

Thrust

A jet engine “sucks, squeezes, burns and blows.”

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2-20

What is “Drag”?

Lift

Weight

Drag

Thrust

Trim

Skin Friction

Excrescence

Induced

“Pressure”

Lift and Span

Aerodynamic details

Smoothness

Outside surface area

Due to the

influence

of an airfoil on those outboard of it

Due to the rapid growth of the boundary layer

Due to roughness, gaps & antennas

Due to the friction in the boundary layer next to the skin to the air flowing over the skin.

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2-21

What & Why Trim?

Lift

Weight

Drag

Thrust

Trim

Trim comes from a wing like surface mounted on the back of the airplane

To change the tilt of the airplane

increase down load - airplane nose goes up

decrease down load - airplane nose goes down

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2-22

Airplane Controls

Flaps

Spoilers

Aileron

Rudder

Elevators

Slats

Fin

Stabilizer (Tail)

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2-23

Airplane Stability

Lift

Weight

A stable system

A stable airplane

Move the ball away from the bottom and it returns to the bottom

Because ball’s center of gravity is above the bottom of the bucket

Move the nose of the airplane up and the airplane’s nose will come back down.

Because airplane’s center of lift is aft of the center of weight

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2-24

How does an airplane turn?

It banks.

Lift

Weight

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2-25

Why do airplanes have rudders?

To balance an inoperative engine and crosswinds.

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2-26

Design Envelope

Takeoff and Landing Distances

Fatigue

Brake Capability

Engine out takeoff

Stall Margins

Pressurization

Speed margins

System redundancy

Flutter

Situation Awareness

Structural Strength margins

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The Plane that Taught America to Fly

Note: Dr. Cairns has around 100 hrs in this make and type, over 200 hours in similar type aircraft

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We will have an opportunity to crawl around one of These!

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The Greatest Fighter Aircraft Ever(according to the Military Channel)

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The Funny Looking X29(forward swept wing for better maneuverability)

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Spacecraft

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More Spacecraft

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The Road Map