ASE 1013 Midterm

Who were the Wright Brothers?

Orville and Wilbur Wright; pioneers of powered flight.

What was significant about the Wright Brothers' first successful flight?

It demonstrated controlled, powered, sustained flight.

What are the four major stages of aircraft development?

Early Years, Jet Age, Space Race, and Modern Age.

Early Years: what was the general aircraft trend?

Rapid development of powered aircraft and basic aircraft technology such as lightweight piston engines and wind tunnels.

Jet Age: what was the major trend?

Emergence of systems engineering, radar, transistors, composite materials, and the introduction of jet engines.

What do jet engines require mastery over?

Compressible flow, turbo machinery, and combustion stability.

Space Race: what was the major trend?

Aerospace expanded from aircraft into rockets and spaceflight.

Modern Age: what is a major trend?

Advanced, highly integrated systems, autonomy, and new aerospace technologies.

Who is Frank Whittle?

British Engineer who is credited for co-creating the jet engine

Who is Hans van Ohain?

Germain Engineer who is credited for co-creating the jet engine?

Theodore von Karman

Pioneered math and science in aeronautics, led/established JPL, and established the Karman line

Who is Richard Whitcomb?

Developed the “area rule” to reduce transonic drag and winglets to also reduce drag and cut fuel use

Who is Robert T. Jones?

Recognized benefits for swept back wings for high-speed aircraft which helped shape the jet age

Who is Chuck Yeager?

Famed flying ace who was credited to be the first person to break the sound barrier (mach 1)

Who is Albert Crossfield?

Famed for flying twice the speed of sound (Mach 2)

Who is Clarence “Kelley” Johnson?

Pioneered revolutionary aircraft such as the U2, led SkunkWorks which pioneered a distinctive way of rapid engineering development

Who is Wenher von Braun?

Pioneered rockets such as the first rocket to reach space (the V2), liquid propulsion, and human spaceflight with rockets such as Saturn V

Who is Juan Trippe?

Pioneered international commercial aviation with Pan American Airlines. Made global air travel possible

Who is Jacqueline Cochran?

Pioneered aviation for women, was the first woman to break the sound barrier.

What made aerospace engineering unique?

It integrates many disciplines into highly complex, tightly coupled systems.

Why can't aerospace components always be optimized independently?

Improving one subsystem can negatively affect the overall system.

What is systems engineering?

Integrating subsystems so the complete aerospace system works together.

What disciplines contribute to aerospace engineering?

Geometry, aerodynamics, propulsion, structures, controls, testing, and more.

What are the three main aerospace employers?

Academia, government, and industry.

Startup vs. large aerospace industry: what is the general difference?

Startups are typically smaller, more fulfilling but riskier; large firms have greater resources, you work a specialized roles, and you have established structures.

What is the first step of the engineering design process?

Identify the problem or need.

What’s the second step of the engineering design process?

Research.

What’s the third step of the engineering design process?

Analysis.

What’s the fourth step of the engineering design process?

Design.

What’s the fifth step of the engineering design process?

Experimentation and testing.

What’s the sixth step of the engineering design process?

Data interpretation.

What is the final step in the basic design flow?

Improvement.

Why is aerospace design an iterative process?

Testing and analysis reveal changes needed to improve the design.

What are degrees of freedom (DOF)?

Independent ways an object can translate or rotate.

How many DOF does a point mass have in 3D?

3: translation in x, y, and z.

How many DOF does a rigid body have in 3D?

6: three translations and three rotations.

What are the three rotational DOF?

Roll, pitch, and yaw.

What axis does roll revolve around?

X

What axis does pitch revolve around?

Y

What axis does yaw revolve around?

Z

What aircraft control produces roll?

Ailerons.

What aircraft control produces pitch?

Elevators.

What aircraft control produces yaw?

Rudder.

What is oscillatory motion?

Motion that repeatedly moves back and forth around an equilibrium position.

Why is pendulum motion important in aerospace?

Pendulums model oscillatory motion in aerospace systems.

What is the small angle approximation and when it is valid?

We can assume that sin(theta) = theta which enables us to view pendulums as simple harmonic motion. This is only valid for angles 10-15 degrees of less.

What happens to pendulum period as length increases?

The period increases.

What does the experimental data section achieve?

Raw measured data from the experiment and observed trends

What does the apparatus description include?

Apparatus details, dimensions, model numbers, and labeled photographs when useful.

What should Results and Discussion accomplish?

Explain trends, compare results, and connect them to engineering concepts.

What should an engineering conclusion contain?

Numerical results, key findings, and significant trends.

What is an Aerostat aircraft and how does it fly?

An aerostat uses buoyancy to fly, blimps and balloons are an example of this

What is an Aerodyne aircraft and how does it fly?

An Aerodyne aircraft uses aerodynamic forces, such as lift, to stay airborne. Airplanes and helicopters and example of this.

What is lift-to-drag ratio (L/D)?

A ratio of lift to drag. Higher L/D usually indicates better aerodynamic efficiency and more lift per each unit of drag.

Why does higher L/D generally mean better range?

More lift is produced relative to drag, allowing more efficient forward travel.

What is wing loading (W/S)?

Aircraft weight divided by wing area.

What does high wing loading mean?

More aircraft weight is carried per unit wing area.

What does a high wing loading have compared to a low wing loading?

More work on the wings requires more airpseed meaning higher stall speeds, higher takeoff/landing speeds and worse lowspeed performance.

What is aspect ratio?

Wingspan squared divided by wing area. Tells you roughly how long/skinny an wing is or how short and stubby it is.

What does higher aspect ratio generally indicate?

A relatively long, slender wing with lower induced drag.

What does a high aspect ratio generally indicate?

Long skinny wings with lower drag, better efficiency and range. However, becomes more structurally challenging and heavier

What is thrust-to-weight ratio (T/W)?

A ratio of how much thrust an aircraft produces per weight.

What is SFC?

Specific fuel consumption; a measure of how much fuel you consume to produce a given amount of useful output. Essentially, fuel consumption per unit of thrust

Is a higher or lower SFC better, why?

A lower SFC is better, indicates that less fuel is needed to produce the same unit of thrust.

What are the components of takeoff weight?

Crew weight + payload weight + fuel weight + empty weight.

What is crew weight?

The weight associated with the aircraft crew.

What is payload weight?

The weight of what’s being carried, excluding the aircraft itself and its fuel. Usually the crew, passangers, and the cargo

What is fuel weight?

The weight of fuel carried for the mission.

What is empty weight?

The aircraft's weight excluding crew, payload, and usable fuel.

When was the MSU aerospace program established?

1933.

Who was August Raspet?

An important figure in MSU aerospace history identified in the review.

What was August Raspet known for?

Aerospace research centered around boundary layer control. His research transformed MSU into a nationally recognized aerospace research institution.

What did Raspet’s work around Boundary Layer Control achieve?

Dramatically improve low-speed aircraft performance and STOL (short takeoff and landing) capacities.

What was MARVEL?

An MSU aerospace project involving an all-composite aircraft.

What is the troposphere?

The atmospheric layer where weather occurs.

What is the general structure of Earth's atmosphere?

It consists of distinct layers with different temperature and physical characteristics.

What is the atmosphere mostly made of?

About 78% nitrogen.

Where does GPS operate?

Medium Earth orbit (MEO).

What is the Kármán Line?

The review identifies it at 100 km altitude.

What is the space environment like?

It includes vacuum, radiation, microgravity, and debris.

What is Max-Q?

The point of maximum dynamic pressure during flight.

Why is atmospheric understanding important to aerospace?

Atmospheric conditions strongly affect vehicle performance and design.

Why is understanding the space environment important?

Spacecraft must operate through vacuum, radiation, microgravity, and debris hazards.

What should engineers do when a model disagrees with an experiment?

Compare the prediction with the data and investigate the difference.

Why are data and analysis important to engineering decisions?

They provide evidence for evaluating designs and choosing among tradeoffs.

What is a tradeoff in aerospace design?

Balancing competing requirements because improving one aspect can affect another.

What does successful aerospace design balance?

Mission requirements, tradeoffs, data, and engineering judgment.

What does the dynamic pressure equation tell us?

Density decreases with altitude

Velocity increases during launch

Max-Q occurs when these two competing effects produce max aerodynamic loading

How much of the atmosphere is composed by oxygen?

21%

What is the troposphere?

Where we live every day, this is where most of Earth’s weather occurs (this is where air is constantly overturning). Contains about 75% of atmospheric mass.

What happens to temperature as you go up the troposphere?

Temperature decreases with altitude

What is the stratosphere?

Contains the ozone layer with relatively smooth and stable air. Temp increases with altitude

What is the Mesosphere?

Little ozone with very low temperatures, this is where meteors burn up

What is the Thermosphere?

Extremely thin air with high temperatures. This is where the ISS is located as well as Low Earth Orbit (LEO) satellites

What is the exosphere?

Extremely low density, transitions into space, mainly hydrogen and helium.

Why don’t commercial airlines go above the Troposphere?

As altitude increases, air density decreases. This means while there will be less drag, there will also be less lift for the aircraft to maintain cruising speed

What is the International Standard Atmosphere?

A globally agreed reference state of temperature, pressure, and density vs altitude.

What’s the hierarchy of temperature, pressure, density and the fundamental aerodynamic forces?

Temperature determines pressure

Pressure and temperature determine density

Density drives lift, drag, engine performance, and dynamic pressure.

What’s a characteristic constant in orbit?

Orbit is free fall! You’re falling when you orbit but are moving fast enough to not fall into the Earth’s atmosphere.