Flight Dynamics Chpt 3

Front 1

Standard atmosphere

Back 1

A model of the atmosphere based on the aero-
static equation, the perfect gas law, an assumed temperature distribu-
tion, and standard sea level conditions

Front 2

Temperature

Back 2

Property of the atmosphere (tau). Function of altitude

Front 3

pressure

Back 3

Property of the atmosphere (p). Function of altitude

Front 4

density

Back 4

Property of the atmosphere (rho). Function of altitude

Front 5

troposhpere

Back 5

Atmosphere from sea level to the tropopause (h =36,089
ft).

Front 6

Standard sea level conditions

Back 6

Conditions at sea level used to dene
the standard atmosphere.

Front 7

Stratosphere

Back 7

Atmosphere between h=36,089 ft and h=105,000 ft

Front 8

Tropopause

Back 8

Dividing line between the stratosphere and the tropo-
sphere, h=36,089 ft

Front 9

Speed of sound

Back 9

Property of the atmosphere (a). Function of tempera-
ture

Front 10

Viscosity

Back 10

Property of the atmosphere (mu). Function of temperature.

Front 11

Exponential atmosphere

Back 11

An approximate standard atmosphere based
on the assumption of constant temperature. rho= rhos*exp(-h/lambda)

Front 12

Isothermal atmosphere

Back 12

A constant temperature atmosphere. Same as
exponential atmosphere

Front 13

Lift coefficient

Back 13

Nondimensional lift, CL = L/qS

Front 14

Drag coefficient

Back 14

Nondimensional drag, CD = D/qS

Front 15

Wing planform area

Back 15

From the top view of an airplane, it is the area S of
the wing extended from the fuselage centerline to the wing tip (outside
of tip tanks if present).

Front 16

Mach number

Back 16

Ratio of airplane velocity to speed of sound at the alti-
tude the airplane is operating, M = V=A.

Front 17

Reynolds number

Back 17

Ratio of inertia forces to viscous forces, Re = rho*V*L/mu

Front 18

Drag polar

Back 18

The relationship between CD and CL, CD = CD(CL,M,Re)

Front 19

Lift-to-drag ratio

Back 19

Ratio of lift to drag E = L/D. Also called aerodynamic efficiency.

Front 20

Aerodynamic efficiency

Back 20

Lift to drag ratio, E = L/D

Front 21

Zero-lift angle of attack

Back 21

The angle of attack alpha0L at which CL = 0,alpha0L

Front 22

Lift-curve slope

Back 22

The slope of the CL versus alpha curve, CLalpha

Front 23

Basic symmetric airfoil

Back 23

The thickness distribution of the airfoil without camber

Front 24

Camber line

Back 24

the line between the upper and lower sides of a cambered airfoil.

Front 25

Center of pressure

Back 25

The intersection of the airfoil aerodynamic force line of action and the chord

Front 26

Peak suction

Back 26

The point on the chord where the minimum pressure occurs, xps.

Front 27

Ideal lift coefficient

Back 27

Lift coefficient of an airfoil where the minimum drag occurs

Front 28

Thickness ratio

Back 28

Ratio of the maximum thickness to the chord of an airfoil

Front 29

Root chord

Back 29

The chord of the wing at the body reference line, cr.

Front 30

Tip chord

Back 30

The chord at the tip of the wing (outside the tip tank if present), ct

Front 31

Semi-span

Back 31

The distance b/2 between the root chord and the tip chord

Front 32

Sweep

Back 32

The angle capital lambda that a particular chord line makes with the y axis.

Front 33

aspect ratio

Back 33

A nondimensional quantity which indicates the slenderness of a wing, A = b^2/S

Front 34

taper ratio

Back 34

The nondimensional quantity ct/cr of a wing.

Front 35

mean aerodynamics chord

Back 35

The chord of an equivalent rectangular wing, c.

Front 36

equivalent rectangular wing

Back 36

A rectangular wing which has the same lift and the same moments about the x and y axes.

Front 37

wing incidence

Back 37

Angle iW between the wing chord plane and the body x axis.

Front 38

wing chord plane

Back 38

For a wing with no twist and the same airfoil shape along the span, the surface formed by the chords is a plane.

Front 39

friction drag coefficient

Back 39

The friction drag is the part of the drag caused by skin friction acting over the surface of the airplane, also called parasite drag.

Front 40

Wave drag coefficient

Back 40

The wave drag is the part of the drag caused by the appearance of shock waves on a wing. The shock waves cause the boundary layer to separate

Front 41

Induced drag coefficient

Back 41

The induced drag is the component of the drag induced by the rotational
ow about the wing tip vortices.

Front 42

Equivalent parasite area method

Back 42

The parasite area is the area touched by the air flow over an airplane. Equivalent parasite area is parasite area corrected for Mach number, interference, thickness, etc

Front 43

Skin friction coefficient

Back 43

The equivalent parasite area divided by the planform area

Front 44

Compressibility factor

Back 44

Gives the effect of Mach number on the equivalent parasite area.

Front 45

Interference factor

Back 45

Gives the effect of interference effects on the equivalent parasite area.

Front 46

Form factor

Back 46

Gives the effect of wing and body thickness on the equivalent parasite area

Front 47

Fineness ratio

Back 47

For a body shape, it is the length of the body divided by the maximum diameter

Front 48

Wetted area

Back 48

The wetted area is the surface area of an airplane which is touched by the air
flow, Swet

Front 49

Mach number for drag divergence

Back 49

The Mach number at which the drag
begins to increase rapidly do to the appearance of shock waves, MD

Front 50

Oswald's efficiency factor

Back 50

It gives the increase in induced drag due to the dierence between an elliptic planform and another planform, e

Front 51

Parabolic drag polar

Back 51

The drag polar that has the shape of a parabola,
CD = CD0(M) + K(M)CL^2

Front 52

Zero-lift drag coefficient

Back 52

It is the drag coefficient CD0 associated with the parabolic drag polar when CL = 0.

Front 53

Induced drag coefficient

Back 53

It is the drag coefficient K*CL^2 associated with the parabolic drag polar

Front 54

Induced drag factor

Back 54

It is the term K in the parabolic drag polar

Front 55

Corrected thrust

Back 55

A non-dimensional thrust used to represent thrust data.

Front 56

Corrected specic fuel consumption

Back 56

A non-dimensional specificc fuel consumption used to represent specific fuel consumption data.

Front 57

Corrected engine speed

Back 57

A non-dimensional engine speed used to represent engine speed data

Front 58

Ideal subsonic airplane

Back 58

A subsonic jet airplane characterized by a parabolic
drag polar with constant coefficients, thrust independent of velocity, and specific fuel consumption independent of velocity and power setting

Front 59

Ideal SBJ

Back 59

The ideal representation of the airplane (SBJ) in App. A.