AERO 20] Test 3 Fall 2005 Name 59 «A or}
1. 5% Sketch drag coefcient vs Mac for an airfoil, showing subsonic, transonic and supersonic
trends. Show Mcr and Mad. Also, indicate the prole and wave drag components.
2. 10% A sonic boom is heard due t
CHAPTER 7 Principles of Stability and Control
7.1 INTRODUCTION
PAGE 587
While airplane performance is governed by forces along and perpendicular to the flight
path, airplane stability and control is governed by moments about the center of gravity,
with th
7.4 ABSOLUTE ANGLE OF ATTACK
PAGE 598
L 0
Absolute Angle of Attack: a
o When the absolute angle of attack is not, then the lift is not, no matter what the
camber of the airfoil.
7.5 CRITERIA FOR LONGITUDINAL STATIC STABILITY
PAGE 600
Longitudinal stabili
7.7 CONTRIBUTION OF THE TAIL TO Mcg
PAGE 609
Two interference effects influence the tail aerodynamics:
o The airflow at the tail is deflected downward by the downwash due to the finite
wing; that is, relative wind seen by the tail is not in the same direc
7.12 CONCEPT OF STATIC LONGITUDINAL CONTROL
PAGE 621
In order for an airplane to change its velocity and still remain balanced, the only way for
this to be accomplished is to effectively change the moment coefficient curve for the
airplane.
Effect of elev
Chapter 8 Space Flight (Astronautics)
8.3 LANGRANGES EQUATION
x g
q1 coordinate:
d B B
0
dt q1 q1
q2 coordinate:
d B B
0
dt q2 q2
q3 coordinate:
d B B
0
dt q3 q3
8.4 ORBIT EQUATION
PAGE 655
PAGE 658
GmM
2
, with G 6.67 1011 m3 kg s
2
r
Because Lagranges
8.6 KEPLERS LAWS
Keplers First Law: A satellite describes an elliptical path around its center of attraction.
Keplers Second Law: In equal times, the areas swept out by the radius vector of a satellite
are the same.
Keplers Third Law: The periods of any t
8.8 SOME ORBITAL MANEUVERS
PAGE 681
The orbit or trajectory of a spacecraft is uniquely determined by the conditions at burnout
of the rocket booster. The motion of a spacecraft after burnout is at the mercy of
gravitational force, and its flight path bec
CHAPTER 9 - Propulsion
9.2 PROPELLER
PAGE 753
The net thrust of a propeller engine is defined as T L cos Dsin where .
PA
TV
or A
P
P , where P is the shaft brake power, and PA is the
Propeller Efficiency:
power available from the propeller.
o 1 always be
W
b2
4
spe
Work:
, where b is the bore (girth) size and s is the shaft (length) size.
o Girth is more important than length.
d
b2
sN
PA
mech rpm dpe
120
4
Displacement:
A supercharger compresses the incoming air before it reaches the intake manifold,
i
9.6 TURBOFAN ENGINE
PAGE 781
A turbofan is a turbojet engine that has a large ducted fan mounted on the shaft ahead of
the compressor. The turbine drives both the fan and the compressor.
o The ducted fan accelerates a large mass of air that flows between
9.8 ROCKET ENGINE
PAGE 788
Rocket engines are different than other engines because they carry both the fuel and the
oxidizer, and so it is completely independent of the atmosphere for combustion, which
means it can operate in the vacuum of space.
T m fuel
CHAPTER 5 Airfoils, Wings, and Other Aerodynamic Shapes
5.2 AIRFOIL NOMENCLATURE
PAGE 290
Airfoil The cross-sectional shape obtained by the intersection of the wing with a
perpendicular plane.
Mean Camber Line The locus of the points halfway between the u
Disadvantages of solid propellants compared to liquid propellants:
o The specific impulse of solid propellants is considerably less than that of liquid
propellants. Generally the specific impulse of solid rockets ranges from 200 to 300 s.
o Once a solid r
CHAPTER 6 Elements of Airplane Performance
6.1 INTRODUCTION: THE DRAG POLAR
PAGE 440
The airplane is considered a rigid body on which four natural forces are exerted: lift, drag,
propulsive thrust, and weight.
6.2 EQUATIONS OF MOTION
PAGE 447
Four physica
5.9 CRITICAL MACH NUMBER AND CRITICAL PRESSURE COEFFICIENT
PAGE 327
Critical Mach Number The free-stream Mach number at which sonic flow is first
obtained somewhere on the airfoil surface.
o Important because at some Mach number greater than the critical
5.14 CALCULATION OF INDUCED DRAG
PAGE 363
Induced Drag The difference in the actual drag and the imaginary drag component
resulting from the force directly perpendicular to the free-stream velocity.
Di L sin i Li because the values of i are generally smal
5.16 SWEPT WINGS
PAGE 381
When the wings of subsonic aircraft are swept, we delay drag divergence to higher
Mach numbers.
M for airfoil
M cr for airfoil < Actual M cr for swept wing < cr
, where is the degree of sweep.
cos
o
This is caused by the fact th
o Dynamic Deals with the time history of the vehicles motion after it initially
responds to its static stability.
When an airplane is flying at an angle of attack such that its moments
about the center of gravity are zero, the airplane is therefore in eq
FOR A PULL-UP MANEUVER
R
Turn Radius:
V2
g n 1
g n 1
V
Turn Rate:
FOR A PULL-DOWN MANEUVER
R
Turn Radius:
V2
g n 1
g n 1
V
Turn Rate:
Airplanes with lower wing-loadings will have smaller turn radii and larger turn rates.
Rmin
Minimum Turn Radius:
max g
M
AERO 201
Test 2
Fall 2004
Name _
(all problems are valued at 10% unless otherwise noted)
1. Consider a wing at an arbitrary angle of attack, . The lift, L, and drag, D, forces are perpendicular and parallel to the freestream velocity, respective
um: 191 Test: FIJI 1005 Hum: '51:" Lia-H can.
I. {I'M-H Consider a rectangular wing at (I: = 10. Th:
span is I II. Th: chard in! ft. Th1: Hui-mat {N} v
and Axial ML} [mm are Hl lb and 5 ll'l " I
1perpmdlcu|l and parallcl to IE1: wing I:th respect
0.0683 slug (= 2.2 lbm) = 1 kg 1.8 R = 1.0 K
o o
3.281 ft = 1 m ( _ ) R = ( _ ) F + 460
o o
0.224 lb (= 0.102 kgf) = 1 N ( _ ) K = ( _ ) C + 273
o o
pS = 2116 lb/ft2 = 1.013 x 105 N/m2 = 1 atm s = 0.002378 lb sec /ft = 1.225 kg/m as = 1116 ft/s = 340 m/s
0.0683 slug (= 2.2 lbm) = 1 kg 1.8 R = 1.0 K
o o
3.281 ft = 1 m ( _ ) R = ( _ ) F + 460
o o
0.224 lb (= 0.102 kgf) = 1 N ( _ ) K = ( _ ) C + 273
o o
pS = 2116 lb/ft2 = 1.013 x 105 N/m2 = 1 atm s = 0.002378 lb sec /ft = 1.225 kg/m as = 1116 ft/s = 340 m/s
Note: be aware of notations. For example, the variable "a" has multiple uses think of the context. Also, c p is the "specific heat" of a gas, but C p is the "pressure coefficient" - be aware of the units and the contextual use of each.
0.0683 slug (= 2.2
0.0683 slug (= 2.2 lbm) = 1 kg 1.8 R = 1.0 K
o o
3.281 ft = 1 m ( _ ) R = ( _ ) F + 460
o o
0.224 lb (= 0.102 kgf) = 1 N ( _ ) K = ( _ ) C + 273 TS = 59oF = 15oC = 519oR = 288oK
o o
pS = 2116 lb/ft2 = 1.013 x 105 N/m2 = 1 atm = 0.002378 lb sec /ft = 1.225
0.0683 slug (= 2.2 lbm) = 1 kg 1.8 R = 1.0 K pS = 2116 lb/ft2 = 1.013 x 105 N/m2 = 1 atm = 0.002378 lb sec /ft = 1.225 kg/m s
0 (h - h1 ) p = e RT p1
3.281 ft = 1 m ( _ ) R = ( _ ) F + 460
o o
0.224 lb (= 0.102 kgf) = 1 N ( _ ) K = ( _ ) C + 273
o o
o
o
T
0.0683 slug (= 2.2 lbm) = 1 kg 1.8 R = 1.0 K pS = 2116 lb/ft2 = 1.013 x 105 N/m2 = 1 atm = 0.002378 lb sec /ft = 1.225 kg/m s
0 (h - h1 ) p = e RT p1
3.281 ft = 1 m ( _ ) R = ( _ ) F + 460
o o
0.224 lb (= 0.102 kgf) = 1 N ( _ ) K = ( _ ) C + 273
o o
o
o
T