Aero 1 CH 1 Flashcards
1
Q
Scalar
A
Quantity that represents only magnitude. Time, Temp, Volume.
2
Q
Vector
A
Quantity that represents magnitude and direction. Displacement, Velocity, Acceleration
3
Q
Displacement(s)
A
Distance and direction
4
Q
Velocity(V)
A
Speed and direction
5
Q
Speed
A
Scalar equal to the magnitude of the velocity vector.
6
Q
Acceleration(a)
A
Rate and direction of a boy’s change of velocity.
7
Q
Force(F)
A
Push or pull exerted on a body. F=m·a
8
Q
Mass(m)
A
Quantity of molecular material that comprises an object
9
Q
Volume(v)
A
Amount of space occupied by an object.
10
Q
Density(ρ)
A
Mass per unit volume ρ=mass/volume
11
Q
Weight
A
Force with which a mass is attracted towards the center of the earth by gravity
12
Q
Moment(M)
A
Vector quantity equal to a force(F) times the distance(d) from the point of rotation that is perpendicular to the force.
13
Q
Work(W)
A
When a force acts on a body and moves it. W=F·s
14
Q
Power(P)
A
Work done per unit of time. P=W/t
15
Q
Energy
A
Scalar measure of a body’s capacity to do work. TE=PE+KE
16
Q
Potential energy(PE)
A
Ability of a body to do work because of its position or state of being. PE=weight·height=mgh
17
Q
Kinetic energy(KE)
A
Ability of a body to do work because of it’s motion. KE=½ mV²
18
Q
Newton’s first law
A
Equilibrium
A body in rest tends to remain in rest and a body in motion tends to remain in motion in a straight line at a constant velocity unless acted upon by some unbalanced force.
19
Q
Equilibrium
A
absence of acceleration either linear or angular.
20
Q
Equilibrium flight
A
Sum of all forces and sum of all moments around the center of gravity are equal to zero.
Straight line constant velocity
thrust, drag, lift, and weight acting equally.
21
Q
Trimmed flight
A
Sum of all moments around the center of gravity is equal to zero.
22
Q
Newton’s second law
A
Acceleration
An unbalanced force(F) acting on a body produces an acceleration (a) in the direction of the force that is directly proportional to the force and inversely proportional to the mass(m) of the body. a=F/m a=Vout-Vin/time
23
Q
Newton’s third law
A
Interaction
For every action, there is an equal and opposite reaction.
24
Q
Atmosphere Composition
A
78% nitrogen, 21% oxygen, 1% other gasses(argon and carbon dioxide). To be considered uniform mixture of these gasses.
25
Static pressure (Ps)
The pressure particles of air exert on adjacent bodies.
26
Ambient static pressure
Equal to the weight of a column of air over a given area.
27
Air density (ρ)
Total mass of air particles per unit of volume.
28
Temperature (T)
Measure of the average random kinetic energy of air particles.
29
Average lapse rate
Rate of temperature change. 2°C (3.57°F) per 1000ft
30
Isothermal layer
36,000-66,000ft the air remains a constant -56.5°C (-69.7°F)
31
Humidity
Amount of water vapor in the air. As humidity increases, air density decreases.
32
Viscosity (μ)
Measure of air's resistance to flow and shearing. Liquids- as temp increases viscosity decreases
Air-air temp increases viscosity increases
33
Local speed of sound
Rate at which sound travels through a particular air mass. As temperature increases, the speed of sound increases.
34
Standard atmosphere
Average zero humidity conditions at middle latitudes.
35
Static Pressure Pso
29. 92 inHg
| 1013. 25 mbar
36
Temperature To
59°F
| 15°C
37
Average Lapse Rate
3.57°F/1000ft
| 2°C/1000ft
38
ρo
.0024 slugs/ft³
| 1.225g/l
39
Local speed of sound
661. 7 knots
| 340. 4 m/s
40
General gas law
P=ρRT
| R is a constant for any given gas
41
Altitude
Geometric height above a given plane reference.
42
True altitude
Actual height above mean sea level.
43
Pressure altitude(PA)
Height above the standard datum plane. 29.92 inHg
44
Density altitude(DA)
The altitude in the standard atmosphere where the air density is equal to local air density. Found by correcting pressure altitude for temperature or humidity deviations from the standard temp.
45
Aircraft
Any device used or intended to be used for flight in the air.
46
Airplane
heavier than air fixed wing aircraft that is driven by an engine driven propeller or a gas turbine jet and is supported by the dynamic reaction of airflow over its wings.
47
Fuselage
structure of the airplane to which all other components are attached. 3 types- truss, full monocoque, and semi monocoque
48
Truss
Consists of a metal or wooden frame over which a light skin is stretched. strong and easy to repair, but heavy
49
Full monocoque
Extremely light and strong because it consists of only a skin whell which is highly stressed but almost impossible to repair if damaged.
50
Semi-monocoque
a modified version of monocoque having skin, transverse frame members, and stringers, which all share in stress loads and may be readily repaired if damaged.
51
Wing
An airfoil attached to the fuselage and is designed to produce lift.
52
Ailerons
control surfaces attached to the wing to control roll.
53
Flaps
High lift devices attached to the wing to increase lift at low airspeeds.
54
Full cantilever
internal bracing
55
Empennage
assembly of stabilizing and control surfaces on the tail of an airplane.
Consists of the aft part of the fuselage, the vertical stabilizer, and the horizontal stabilizer.
56
Rudder
Upright control surface attached to the vertical stabilizer to control yaw.
57
Elevators
Horizontal control surfaces attached to the horizontal stabilizer to control pitch.
58
Landing gear
Permits ground taxi operations and absorbs the shock encountered during takeoff and landing.
59
Engine
Provides the thrust necessary for powered flight.
60
Center of gravity (CG)
is the point at which all weight is considered to be concentrated and about which all forces and moments(yaw, pitch, and roll) are measured.
61
Longitudinal axis
Passes from the nose to the tail.
62
Roll
Movement of the lateral axis around the longitudinal axis.
63
Lateral axis
wingtip to wingtip.
64
Pitch
Movement of the longitudinal axis around the lateral axis.
65
Vertical Axis
Passes through the CG
66
Yaw
Movement of the longitudinal axis around the vertical axis is called yaw.
67
Wingspan(b)
Length of a wing, measured from wingtip to wingtip.
68
Chordline
infinitely long, straight line which passes through the leading and training edges of the wing.
69
Chord
Measure of the width of an airfoil.
70
Root chord Cr
Is the Chord at the wring centerline.
71
Tip chord Ct
measured at the wingtip.
72
Average chord(c)
Is the average of every chord from the wing root to the wingtip.
73
Wing area(S)
Apparent surface area of a wing from wingtip to wingtip.
| S=bc
74
Taper
Reduction in the chord of an airfoil from root to tip.
75
Taper Ratio (λ)
Ratio of the tip chord to the root chord λ=Ct/Cr
76
Sweep Angle (Λ)
Is the angle between the lateral axis and a line drawn 25% aft of the leading edge.
77
Aspect ratio (AR)
Ratio of the wingspan to the average chord. AR=b/c
78
Wing Loading (WL)
Ratio of an airplanes weight to the surface area of its wings.
WL=W/S
79
Angle of incidence
The angle between the airplane's longitudinal axis and the chordline of the wing.
80
Dihedral angle
The angle between the spanwise inclination of the wing and the lateral axis. Upward slow of the wings when viewed from the front.
81
Anhedral
Negative dihedral.
82
Steady Airflow
Exists if at every point in the airflow static pressure, density temperature and velocity stay the remain constant over time.
83
Streamline
Path that air particles follow in steady state.
84
Streamtube
A collection of many adjacent streamlines.
85
Continuity Equation
Amount of mass passing any point by multiplying area by velocity and then the density.
ρ1A1V1=ρ2A2V2
Simplified as: A1V1=A2V2
86
Bernoilli's Equation
Gives the relationship between pressure and velocity of steady airflow.
Pt=Ps+q
q=½ ρV²
87
Dynamic pressure (q)
Pressure of a fluid resulting from its motion
| q=½ ρV²
88
Total pressure (Pt)
Sum of static and dynamic pressure.
89
Dynamic pressure
Cannot be measured directly, but can be derived using bernoulli's equation. q=Pt-Ps
90
Pitot static system
Consists of a pitot tube that senses total pressure (Pt), a static port that senses ambient static pressure (Ps), and a mechanism to compute and display dynamic pressure.
91
KIAS
Airspeed indicated
92
Instrument error
Caused by the static pressure port accumulating erroneous static pressure.
93
Calibrated airspeed (CAS)
Indicated airspeed is corrected for instrument error.
94
Compressibility error
Ram effect of air in the pitot tube resulting in higher than normal airspeed indications at airspeeds approaching the speed of sound
95
Equivalent airspeed (EAS)
True airspeed at sea level on a standard day that produces the same dynamic pressure as the actual flight condition. Found by correcting calibrated airspeed for compressibility error.
96
True airspeed (TAS)
is the actual velocity at which an airplane moves through the air mass.
TAS is EAS corrected for the difference between the local air density (ρ) and the air density of the air at sea level on a standard day (ρo)
½ ρ(TAS)²= ½ ρo(EAS)²
TAS=√(ρo/ρ)EAS or TAS=√(ρo/ρ)IAS
97
Ground speed
Airplanes actual speed over the ground. TAS corrected for wind.
GS=TAS-HEADWING
GS=TAS+TAILWIND
98
Mach Number
Ratio of the true airspeed to the local speed of sound.
| M=TAS/LSOS
99
Critical Mach number (Mcrit)
is the free airstream Mach number
that produces the first evidence of local sonic flow. Simply put, an airplane exceeding MCRIT
will have supersonic airflow somewhere on the airplane.
100
Pitch attitude (θ)
is the angle between an airplane’s longitudinal axis and the horizon.
101
Flight path
the path described by its center of gravity as it moves through an air
mass.
102
Relative wind
the airflow the airplane experiences as it moves through the air. It is
equal in magnitude and opposite in direction to the flight path.
103
Angle of attack (α)
is the angle between the relative wind and the chordline of an airfoil.
Angle of attack is often abbreviated AOA.
104
mean camber line
a line drawn halfway between the upper and lower surfaces
105
positive camber
If the mean camber line is above the chordline
106
negative camber
mean camber line is below the
| chordline.
107
symmetric airfoil
mean camber line is coincident with the
| chordline.
108
aerodynamic center
the point along the chordline around which all changes in the aerodynamic force take place. On a subsonic airfoil, the aerodynamic center is located approximately one-quarter (between 23% and 27%) of the length of the chord from the leading
edge.
109
Spanwise flow
airflow that travels along the span of the wing, parallel to the leading edge.Spanwise flow is normally from the root to the tip. This airflow is not accelerated over the wing
and therefore produces no lift.
110
Chordwise flow
air flowing at right angles to the leading edge of an airfoil. Since chordwise flow is the only flow that accelerates over a wing, it is the only airflow that produces lift.
111
aerodynamic force (AF)
is the net force that results from pressure and friction distribution over an airfoil, and comes from two components, lift and drag.
112
Lift (L)
the component of the aerodynamic force
| acting perpendicular to the relative wind.
113
Drag (D)
the component of the aerodynamic force acting parallel to and in the same direction as the relativewind.
114
Lift(L)
L=qScl=½ ρV²SCl
| Cl=coefficent of lift
115
Drag(D)
D=qSCd=½ ρV²SCd
| Cd=Coeffiecent of drag
116
Aerodynamic force AF
AF=qScf=½ ρV²SCf
| Cf=Coeffiecent of force
