問題一覧
1
stall
is the inability of the air to travel over the surface of the wing against the adverse pressure gradient behind the point of minimum pressure.
2
Friction drag can be reduced by
delaying the point at which laminar flow becomes turbulent.
3
The aero foil produces zero lift at a certain
negative angle of attack
4
Vortex generators
move the transition point forwards towards the leading edge of the wing.
5
●An increase in aircraft weight
will increase the stall speed.
6
As an incompressible fluid flows through a duct of varying cross sectional area, the mass flow rate remains constant. this is defined as
the principle of continuity.
7
Drag acts in a direction parallel with the relative airflow, and is therefore
always perpendicular to lift (where generated).
8
Profile drag
increases with the square of the IAS
9
●symmetrical aeorfoil, with all other things being equal, will stall
at higher angle of attack as a cambered aerofoil, but will produce less lift at any given angle of attack bellow th
10
●when trailing edge flaps are deployed, the camber and the angle of attack are both
increased
11
Angle of attack is
the angle between oncoming air (or relative airflow) and the chord line of the wing.
12
An increase in the angle of attack will cause
the centre of pressure to move forward
13
●The resultant airflow that affects the wing is made
by the relative horizontal and vertical airflow components.
14
Wing tip vortices on conventional aeroplanes create
additional drag and reduce lift.
15
the aspect ratio of a wing is the ratio of
its span to its aerodynamic chord
16
The chord line of a wing is a line that
runs from the centre of the leading edge of the wing to the trailing edge.
17
Ground speed can be determined
by the vector sum of the aircraft's true airspeed and the current wind speed and direction.
18
Longitudinal dihedral angle is defined as
the difference the angle of incidence of the mainplane and tailplane.
19
●Wing loading is calculated by
weight divided by gross wing area.
20
Skin friction drag increases with
increasing turbulent boundary layer.
21
Induced drag
is greater at low aspect ratio wing.
22
If the weight of an aircraft is increased,
minimum drag speed will increase