POF Q7 - 3D Flow Flashcards

1
Q

The directional flow of the trailing tip vortex is as follows….

a.When viewed from behind, the vortex is anti- clockwise around the left wing tip and clockwise around the right wing tip

b.When viewed from behind, the vortex is clockwise around the left wing tip and clockwise around the right wing tip

c.When viewed from behind, the vortex is anti- clockwise around the left wing tip and anti-clockwise around the right wing tip

d.When viewed from behind, the vortex is clockwise around the left wing tip and anti-clockwise around the right wing tip

A

d.When viewed from behind, the vortex is clockwise around the left wing tip and anti-clockwise around the right wing tip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which statement best describes the cause of span wise flow?

a.The adverse pressure gradient causing flow separation

b.The laminar boundary layer being accelerated rearward

c.The changing pressure gradient along the wing span

d.The changing flow speeds along the wing span

A

c.The changing pressure gradient along the wing span

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which combination is likely to give way to the strongest tip vortices?

a.constant lift production, constant airspeed, high aspect ratio

b.Low aspect ratio, low airspeed, high lift production.

c.low lift production, low aspect ratio, high airspeed

d.High aspect ratio, low airspeed, high lift production.

A

b.Low aspect ratio, low airspeed, high lift production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What can be said about the effective angle of attack on a wing section with strong vortices.

a.The effective angle of attack will remain unaffected

b.The effective angle of attack will increase compared to a weaker vortex section

c.The effective angle of attack will only change with a change in speed

d.The effective angle of attack will reduce compared to a weaker vortex section

A

d.The effective angle of attack will reduce compared to a weaker vortex section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The direction of movement of Span Wise Flow on top of the wing is from…

a.Wing tip to Wing root

b.Trailing edge to leading edge

c.Leading edge to trailing edge

d.Wing root to wing tip

A

a.Wing tip to Wing root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The induced angle of attack is the result of:

a.change in direction of flow due to the effective angle of attack

b.downwash due to flow separation

c.a large local angle of attack in a two dimensional flow

d.downwash due to tip vortices

A

d.downwash due to tip vortices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Wake turbulence is most severe when caused by a large, heavy, clean aircraft?

Select one:
True
False

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The angle between Relative Airflow (RAF) and Effective Airflow (EAF) is known as?

a.Induced Drag

b.Effective Angle of Attack

c.Effective Drag

d.Induced Angle of Attack

A

d.Induced Angle of Attack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

As alpha increases, the differential pressure between the upper and lower surfaces of the wing [ ]. In turn this [ ] strength and
[ ] of the tip vortices.

A

[increases] [increases] [size]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Wing tip vortices have a secondary effect of creating wake turbulence. Wake turbulence migrates downwards due to downwash. At what distance below the aircraft is this said to stabilise?

a.900ft

b.500ft

c.300ft

d.1200ft

A

a.900ft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly