Chapter 3: Aerodynamic Forces

Question 1

What is the term used to describe force over a certain area

Answer 1

Normal force, or preassure

Question 2

What is the definition of a fluid

Answer 2

A substance, either liquid or gas, that readily changes shape when acted in by forces

Question 3

What are two major features of air as expressed in this chapter

Answer 3

Air is viscous and compressable

Question 4

What is fluid compressability

Answer 4

The ability of a fluid to change density when it flows

Question 5

What is a good way to describe viscosity

Answer 5

The intramolecular stickiness of a molecule

Question 6

What is dFt/dS

Answer 6

Shear stress

Question 7

What is dFn/dS

Answer 7

Normal preassure

Question 8

What are the forces involved in air flow over an aircraft

Answer 8

Density, p
Constant if viscosity, Mu
Velocity, V
Length, i think that this is the length that air must flow over a surface
The speed of sound, a
Shape, maybe surface area

Question 9

Once the forces have been accounted for and evaluated through dimensional analysis, what is the equation we have

Answer 9

F=Cf(p/2)V^2S

Question 10

Cf

Answer 10

Coefficient of Force

Question 11

What is the equation for coefficient of lift, keep in mind that this replaces Cf and can also account for drag and pitch

Answer 11

Cl=(2lift)/(pV^2S)

Question 12

What is the expression for Reynolds number

What is it saying

Answer 12

RN=(pVl/Mu)

How many molecules are hitting the surface and how fast, and we must consider how well they stick to eachother

Question 13

What is dynamic pressure, and its equation

Answer 13

The kinetic energy per unit of air

(p/2)V^2

Question 14

What appears to be the least amount of lift a glider can get

Answer 14

6.8 pounds per square foot

Question 15

What is a form of experimental analysis to evaluate the Force expression

Answer 15

Wind tunnels, where forces, shape of aircraft, and pressure can be controlled