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Aerodynamics Final
Elliott's Aerodynamics Final WMU
83
Aviation
Undergraduate 2
12/15/2010

Additional Aviation Flashcards

 


 

Cards

Term
the densisty of water cahnges with depth (T/F)
Definition
False
Term
airplanes were developed primarily by
Definition
trial and error method
Term
Did Bernoulli experiment with flight?
Definition
no
Term
The first successful flight of an aircraft was accomplished with a balloon(T/F)
Definition
True
Term
Aerodynamics is the study of
Definition
air in motion
Term
A balloon that is filled with air that is lighter than the surrounding air rises to a point where the internal air density is equal to the external air density is based on what principle?
Definition
buoyancy
Term
the density of air changes depending on altitude because it is compressible (T/F)
Definition
True
Term
what part of the atmosphere does all weather occur and also most flight operations?
Definition
Troposphere
Term
air density at sea level is ____ dense than air at 10,000ft of altitude
Definition
more
Term
balloons that are navigable are called
Definition
air ships
Term
Sir George Cayley, Otto Lilenthal and Octave Chanute all had what in common
Definition
experimented with gliders in the 1800s
Term
lighter than air aircraft are reliant of what for lateral (as opposed to vertical) movement
Definition

-movement of an air mass

-velocity and direction of the wind

Term
man's first attempt at heavier than air flight was to create birdlike vehicles with wings that flapped (T/F)
Definition
True
Term
Birds are successful fliers because they can achieve lift and thrust with their feathered wings. Airplanes require 
Definition
an engine to develop forward thrust and controls to maneuver in pitch, roll, and yaw, and stability in their design and knowledgeable pilots.
Term
gliders and airplanes are 
Definition
heavier than air machines
Term
who was/were the first to achieve sustained, controlled and powered flight
Definition
Wright Brothers
Term

A chunk of fluid that is suspended in a container of fluid will ________ due to the weight and pressure above the chunk balancing out the higher pressure below the chunk.

Definition
remain still
Term

A small contained bubble of fluid that is lighter than the surrounding fluid ________ due to the higher pressure on the bottom of the bubble.

Definition
rises to the surface
Term

A piece of lead placed in a container of water will ________ due to the weight of the lead being _______ than the fluid that is displaced.

Definition
sink to the bottom, heavier
Term
how are balloons made to be lighter than air
Definition

-filled with lighter than air gas (helium)

-filled with heated air which is less dense than cooler air

Term

Pressure=

(formula)

Definition
force/area
Term
symbol for density
Definition
ρ
Term
approx. temp at tropopause
Definition
-56°C
Term
Air pressure at sea level is ________  than air at 30,000 feet altitude.
Definition
more
Term

The temperature of air decreases on average by how much per 1000ft

Definition
2˚C
Term
the chordline of an aerofoil is 
Definition
a straight line from the leading edge of the trailing edge equidistant from the upper and lower surfaces.
Term
A cambered aerofoil set at 0˚ angle of attack in an air stream will produce
Definition
lift and drag
Term
the angle between the chord line and the aerofoil and the relative airflow is called
Definition
the angle of attack
Term
dynamic pressure is equal to (formula):
Definition
                  ½ ρv²
Term
the thickness:chord ratio of an aerofoil is 
Definition
the ratio of the max thickness of an aerofoil section to it chord.
Term
the center of pressure of an aerofoil is
Definition
the point on the chordline where the resultant lift force acts
Term
If the angle of attack is increased slightly from 0˚, the center of pressure will
Definition
move forward slightly
Term
A symmetrical aerofoil section of a wing which is set at zero degrees angle of incidence will produce in level flight
Definition
zero lift
Term
the air on top of a cambered wing producing lift
Definition
velocity increases, static pressure decreases
Term
aspect ratio
Definition
the ratio of the wingspan to the mean chord
Term
density of a gas (formula)
Definition
mass/volume
Term

The diagram shows the Static pressure and velocity of the airflow around a wing section producing lift.  Which of the below is correct?

Definition
P1 is less than P2, V1 is greater than V2.
Term

The diagram shows the lift curves for two aerofoil sections.  Which of the below is an accurate description of the diagram?

Definition
Airfoil A is symmetrical, but airfoil B is cambered.
Term

The critical angle of attack at which a given aircraft stalls (CL(MAX)) is dependent on the:

Definition
design of the wing (camber etc)
Term
what will result in a stall every time
Definition
exceeding the critical angle of attack
Term
an aircraft stalls when
Definition

The airflow over the top surface of the wing separates which results in a large increase in drag and a large loss of lift.

Term

If an aircraft’s wings are slightly angled upwards from horizontal as you look at it from the front forming a shallow V, this is called:

Definition
dihedral
Term
high aspect ratio wing
Definition
long span and short chord
Term
wing span
Definition
length wingtip to wingtip
Term
a wing is tapered if
Definition
the tip chord is less than the root chord
Term
the stalling angle of an aerofoil of a training aircraft is approximately
Definition
16 degrees
Term
an aircraft's wing has a mean chord of 6m and a span of 30 m. the aspect ratio is 
Definition
5
Term
aspect ratio (formula)
Definition
span2/area
Term
an aerofoil will give a ____force because the angle of attack is negative.
Definition
down
Term
to maintain level flight at a steady airspeed
Definition
thrust must be exactly equal to drag
Term
the stall warning vane on an aircraft wing is located
Definition
just below the leading edge
Term
at positive angles of attack, a wing produces most lift at
Definition
just before the stall
Term
an airplane is in steady-state level flight, therefore:
Definition

thrust equal drag

 

lift equals weight

Term
angle of attack
Definition
angle between the wing chord line and the relative wind
Term
weight acts
Definition
always in line with gravity
Term
when a fowler flap moves back
Definition
wing area increase, camber increases
Term
where does lift act on a wing
Definition
center of pressure
Term
what does "S" represent in the lift equation
Definition
wing area
Term
Bernoullis Theorem
Definition
when dynamic pressure increases, static pressure decreases
Term

For a typical light training aircraft, the optimum angle of attack producing most lift for least drag is approximately:

              

 

Definition
  +4°
Term
wash out of a wing
Definition
a decrease in angle of incidence from root to tip
Term

An antenna of 0.05 sq. ft. of a cross-sectional area (S) produces 1 pound of drag in an airflow with a dynamic pressure (½ρv²) of 25 lbs/sq. ft. What is its drag coefficient?                                                                       

Drag = ½ρv² S Cd

Definition
.80
Term
what happens when landing gear is lowered
Definition
total drag increases
Term
the minimum total drag of an aircraft in flight occurs
Definition
at the speed where parasite drag and lift induced drag are equal
Term
lift induced drag (lift dependent drag) of an aircraft would be increased with
Definition
increased weight
Term
the boundary layer of a body in a moving airstream is
Definition
a thin layer of air over the surface in which the air is retarded by the effects of friction
Term
skin friction drag resulting from a laminar boundary layer will be
Definition
less than from a turbulent boundary layer
Term
A landing gear leg has a drag of 30 lbs at a speed of 100 kts.  Its drag at 200 kts would be
Definition
120lbs
Term
If speed is increased from 150 kts to 300 kts, the Pressure or wake drag due to shape will be
Definition
quadruple 
Term
the drag of an aircraft will ___with an increase in air pressure
Definition
increase
Term

Floating on landing due to ground effect will be most likely during an approach when at:

                                    

Definition

Less than the length of the wingspan above the surface.

 

Term
frost on an aircraft wing will result in
Definition
a decrease in lift and an increase in drag
Term
what phenomena causes lift induced drag
Definition
wing tip vortices
Term
what effect on lift induced drag does entering ground effect have
Definition
it decreases
Term
when the undercarriage is lowered in flight
Definition
form drag will increase and the aircraft will pitch nose down
Term
the point where the boundary layer changes from laminar flow to turbulent flow is called the 
Definition
transition point
Term
laminar flow has
Definition
less friction than turbulent
Term
a high aspect ratio wing (high span to chord ratio, like a glider) decreases ____ _____ ____
Definition
lift induced drag
Term
in straight and level flight, how does parasite drag vary with airspeed
Definition
V2 (directly with the square of the velocity)
Term

The pressure gradient on the rear side of a shape where the air is flowing from Low static pressure to High static pressure is called;

Definition
adverse pressure gradient
Term
the point where the air stops sticking to the shape of an object is called
Definition
separation point
Term

 With regard to "P.L.A.N.n.", the acronym used to determine the capacity of a reciprocating engine to produce power, the "A" refers to what?

Definition
cross secitonal piston area
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