Aerospace Engineering EOC Review

-Wood

-Steel

-Aluminum alloys

-Titanium alloys

-Magnesium alloys

-Nickel alloys

-Fiber-reinforced composites

Commonly used aerospace materials

What are the factors for selecting materials?

Function, Material properties, production

What is the lifespan of an average commercial aircraft?

30 years/60,000 hours/20,000 flights/100,000 miles of taxiing

Total typical commercial aircraft maintenance and service cost are usually _____ the original purchase price.

Double

Pressure differential between fuselage and outside, temperature, and impact load of landing are all examples of _____.

Flight stresses

_____ most effectively reduces airframe weight and improves performance in terms of fuel efficiency + climb rate + G-force loading.

Reducing material density

What did the Wright brothers use to build their aircrafts?

Spruce

-Sensitive to moisture

-Rot and insect damage

-Natural product lower consistency than manmade

-Rarely used today in production aircraft

-Used today in homebuilt and specialty, low-volume productions

-Good strength-to-weight ratio

Wood

Metal alloy that is <0.250 in thick. Often used for the skin of fuselage, wings, control surfaces, etc.

Sheet

Metal alloy that is >0.250 in thick.

Plate

The metal alloy material form where material is plastically deformed into non-uniform cross-sectional parts by large compressive forces in closed dies.

Forging

The metal alloy material form where liquid material is solidified in a mold.

Casting

The metal alloy material form where material is forced through dies to create a uniform cross section. Uses include stiffeners and ribs.

Extrusion

-Most abundant metal in the Earth's crust

-Pure form is relatively soft

-Most widely used, currently

-Readily formed (good with heat treating and tempering), moderate cost

-Excellent resistance to chemical corrosion

-Excellent strength to weight ratio

-Strength and stiffness affected by form (STRONGER = MORE BRITTLE)

Aluminum

What is the most common aluminum alloy?

2024 aka 24ST (93% Al, 4.4% Cu, 1.5% Mn, 0.6% Mg)

Aluminum alloys have high strength applications. Sheet aluminum is often clad with a thin layer of pure aluminum for _____. Aluminum lithium _____ saves weight and can be formed by standard techniques.

Corrosion protection; fuel

-Cheap and easy to make

-First used to construct fuselage

-High strength, temperature, fatigue resistance

Steel alloy

Properties of Steel Alloys are influenced by _____ and _____. Heat treatments result in moderate strength + good ductility OR high strength + brittleness. At 1400-1600°F, carbon goes into _____ solution with Fe.

Heat treating; tempering; solid

-Almost as strong/light as Al

-Almost as temp resistant as steel

-Corrosion-resistant

-Hard to make --- need high temp and stresses, high cost

-Seriousy affected by impurities (H, O, N)

Titanium

Titanium elements are used for jet-engine components, _____ speed aircraft, _____ stress airframe components, landing gear beams, and spindles for all moving tails.

Lower; high

Extreme temperature and pressure causes titanium to flow into the shape of the mold.

Separate pieces of titanium are diffusion-bonded at the same time, forming a joint that is indistinguishable from the original metal.

Super Plastic Forming/Diffusion Bonding

-Good strength to weight ratio

-Tolerates high temperatures

-Easily formed --- casting, forging, and machining

-Prone to corrosion - must have a protective finish

-Flammable

-Should not be used in areas that are difficult to inspect or where the protective finish could erode away

Magnesium

Magnesium is often used for various _____.

Aircraft parts

-Inconel, Rene 41, Hastelloy

-Suitable for hypersonic aircraft and reentry vehicles

-Hallestoy is used primarily in engine parts

-Heavier than aluminum and titanium

-Difficult to form

High temperature nickel alloys

-Used in the empennages of the F-14 and F-15

-Boron/epoxy --- horizontal stabilizers, rudders, and vertical fins

-Mid-1970s carbon fibers --- carbon and epoxy speed brake

1980s saw a boom in composites use (2% on the F15 --> 27% on the AV-8B Harrier)

-Primarily used in wing (skins and substructure), forward fuselage, and horizontal stabilizer

Composites

What are the two necessary and basic parts of composites?

Reinforcement (fiber) and matrix (resin)

Provides the majority of the strength in a composite

Reinforcement

Holds the reinforcement in a specific orientation, improves environmental properties, and provides some strength in a composite

Matrix

Fiberglass - Most common

Graphite - Good strength-to-weight ratio

Kevlar - Toughest

Boron - Strongest

Silicon Carbide - Ceramics reinforcement

Common composites

-High temperature resistance

-Used in engine exhaust nozzles

-Space shuttle uses aluminum structure with heat-protective tiles

Ceramic

The original use for gunpowder in China was:

Entertainment (fireworks)

DaVinci based his Flying Machine design on:

Birds

The person responsible for the first hot air balloon flight was:

The Montgolfier Brothers - they even built one for King Louis XVI

The Wright Brothers completed their first successful flight in:

Kitty Hawk, NC

The pilot of the first commercial flight was:

Tony Jannus

The person who invented the airboat used for the first commercial flight was:

Thomas Benoist

Charles Lindbergh named his aircraft the "Spirit of St. Louis" because:

His investors were based in St. Louis

The first helicopter was developed by:

Igor Sikorsky

The pilot who first flew faster than the speed of sound was:

Chuck Yeager

How large was Sputnik I, the first artificial satellite successfully launched into space?

About 2 ft. diameter

The first human in space was:

Yuri Gagarin on Vostok 1 of the USSR

What were the names of the 2 crafts used in the first successful lunar mission, Apollo 11?

Eagle and Columbia

The first space station:

Salyut 1 of the USSR

The first Mars landing was completed by:

Pathfinder

The first Space Shuttle launched was:

Columbia

Which launched first: Voyager 1 or 2?

Voyager 2, but Voyager 1 overtook it because it was faster

What is one advantage of space telescopes like Hubble?

Less debris from the atmosphere

The main purpose of the International Space Station is/was:

Scientific research

What are the types of UAVs (unmanned aerial vehicles/drones)?

Altair (research), predator (military), mariner (military - border and ocean)

SpaceX's ultimate goal is:

Colonize Mars

How does rocket propulsion produce thrust?

By ejecting stored matter - combustion

Which is more stable: solid rocket fuel or liquid rocket fuel?

Solid rocket fuel

What is the correct orientation for optimal stability of a rocket (from nose to fins)?

CG before CP

A rocket engine has a rating of C4-10. Please interpret.

C - Total impulse code

4 - Average thrust (N)

10 - Delay time (sec)

This space propulsion system utilizes both solid and liquid fuel technologies:

Hybrid Rocket Engine

This space propulsion system utilizes electromagnetic induction to create kinetic energy from electrical energy:

Electrodynamic Tethers

This space propulsion system is super big and is powered by sunlight:

Solar Sails

This space propulsion system uses a nuclear reactor to produce electricity, heat propellant, and create thrust:

Nuclear Propulsion

This space propulsion system uses electrical power to accelerate a propellant:

Electrical Propulsion System

This space propulsion system is the most simple and reliable of them all, with CO2 and N2 connected to a nozzle to propel you forward:

Cold Gas

This space propulsion system utilizes monopropellant during orbit and bipropellant during launch:

Dual Mode

This space propulsion system uses both an oxidizer tank and a fuel tank and is very powerful and efficient:

Bipropellant

This space propulsion system utilizes the conservation of angular momentum:

Reaction Wheels

The four operations of an engine are:

Intake, Compression, Combustion, Exhaust (ICCE)

An engine that utilizes two airstreams:

Turbofan

The main advantage of turbofan engines is:

Efficiency

An engine that uses a turbojet to power a propeller (as the main means of propulsion):

Turboprop

An engine that uses the aircraft's velocity to compress air at speeds under mach 5:

Ramjet

An engine that uses the aircraft's velocity to compress air at speeds over mach 5:

Scramjet

An engine that burns fuel during exhaust in order to push through increased drag near mach 1:

Afterburning turbojet

An engine that mixes fuel and air:

Carburetor

What is a potential problem when using a carburetor?

Icing

An engine that uses blades to push air via the process inlet, compressor, shaft, burner, turbine, nozzle:

Turbojet

An engine that spins a propeller to pull the aircraft forward:

Radial Engine

An engine where four operations occur in one revolution and exhaust and intake happen at the same time:

Two-Stroke Engine

An engine where four operations occur in two revolutions and there are separate pistons for intake and exhaust:

Four-Stroke Engine

The type of engine you are most likely to see on a small private aircraft or automobile would be:

Reciprocating 4-stroke

The type of engine you are most likely to see on a small machine would be:

Reciprocating 2-stroke

The front of the aircraft + where the engine is; responsible for thrust

Power Plant

The end of the aircraft, where the vertical and horizontal stabilizers are

Empennage

The part of the aircraft where passengers sit, the frame is most prevalent, the pilot sits, and to which the skin and aircraft components are attached:

Fuselage

The parts of the aircraft that are responsible for lift:

Wings

The part of the aircraft where the pilot sits:

Cockpit

The inner panels on the wings:

Flaps

What are flaps used for?

Changing lift and drag

The outer panels on the wings:

Ailerons

What are ailerons used for?

Roll control

The main panels on the horizontal stabilizers:

Elevators

What are elevators used for?

Pitch control

The main panel on the vertical stabilizer:

Rudder

What is the rudder used for?

Yaw control

The small panels on the elevators, ailerons, and rudder:

Trim tabs

What are trim tabs used for?

Stable flight

Once an aircraft is stable, the trim tabs go which direction to decrease stress on the pilot yoke?

Opposite the elevators/ailerons/rudder

What is a wing strut?

The part that connects the fuselage to the wing

What does a winglet do?

Increase efficiency, decrease wing drag

What are wing ribs?

The structure that holds up wing layers (look like ribs)

What is stability a trade off of?

Maneuverability and controlability

What is maneuverability?

Aircraft's ability to handle stress of maneuvers

What is Controlability?

Aircraft's ability to react to pilot inputs