AERO 1020 - Theory of Flight: Principles of Mass, Energy, and Aerodynamics

Flashcards covering mass, energy conservation, aerostatics, aerodynamics, the Continuity Principle, Bernoulli's Equation, and airfoil lift concepts from AERO 1020.

What is the scientific definition of mass?

Mass is the quantity of inertia or resistance to acceleration.

What unit is used to measure mass when weight or force is in pounds and gravity is $32.2\,\text{ft/sec}^2$?

Slugs

What is Boyle's Law?

"The volume of a gas is inversely proportional to the pressure." Mathematically, $P_1 V_1 = P_2 V_2$ at constant temperature.

What is Newton's Second Law of Motion?

$F = Ma$ (Force equals mass times acceleration)

How is potential energy defined in contrast to kinetic energy?

Potential energy is stored energy in the body, while kinetic energy is working energy.

How is physical "work" defined?

Work is defined as force multiplied by distance ($\text{force} \times \text{distance}$).

What is the formula for total energy ($TE$) when potential, kinetic, and compressed gas pressure-volume energies are combined?

$$mgh + \frac{1}{2}mv^2 + PV = TE$$

What is Bernoulli's mathematical expression for dynamic pressure?

$$\frac{1}{2}\rho v^2$$

According to the principle of conservation of energy, what happens to static pressure when fluid velocity causes dynamic pressure to increase?

Static pressure must go down so that the total pressure remains constant.

What is aerostatics?

Aerostatics is the study of the forces within stationary fluids.

What is the hydrostatic equation?

$$P_1 - P_2 = \rho gh$$

How do you cause a hot air balloon to rise based on the hydrostatic equation $P_1 - P_2 = \rho gh$?

By heating the air to reduce its density ($\rho$), making the pressure differential greater than the weight.

Why can't an airplane wing float statically like a hot air balloon?

An airplane wing lacks sufficient vertical height ($h$) to generate a hydrostatic pressure differential greater than its weight, making it "heavier than air."

What is aerodynamics?

Aerodynamics is the study of moving air.

What is the formula for the Continuity Principle?

$$V_1 A_1 = V_2 A_2$$

Using the Continuity Principle ($V_1 A_1 = V_2 A_2$), if $V_1 = 90\,\text{ft/sec}$, $A_1 = 10\,\text{in}^2$, and $A_2 = 2\,\text{in}^2$, what is $V_2$?

$$V_2 = 450\,\text{ft/sec}$$

Who was Daniel Bernoulli?

An Austrian physicist/mathematician born in 1700 who studied fluid dynamics (water in pipes) in St. Petersburg, Russia.

What is Bernoulli's Equation relating pressure difference to air density and velocities?

$$P_1 - P_2 = \frac{1}{2}\rho (V_2^2 - V_1^2)$$

What is the standard air density ($\rho$) value based on ICAO standards?

$0.00238\,\text{slugs/ft}^3$ (slugs per cubic foot)

What standard atmospheric pressure values are used in imperial units for calculations in the lecture?

$14.7\,\text{lbs/in}^2$ or $2,117\,\text{lbs/ft}^2$

How is lift defined?

Lift is the net differential pressure between the upper and lower surfaces on an airfoil.

What type of wind tunnel design is shown in this diagram, and what are its four main internal sections?

An Open Return Wind Tunnel, consisting of the Contraction, Test Section, Diffuser, and Fan.

What pressure conditions and flow characteristics around an airfoil are depicted in this diagram?

It shows low pressure on top, high pressure on the bottom, center of lift, camber, upwash, downwash, and net Lift.