Linked Questions

14
votes
2answers
12k views

What is the reason for the poor low-speed characteristics of sweptback wings?

I know there are advantages of swept-back wings delaying shock-wave allowing a aircraft to fly faster. However, what are the disadvantages. I know one of them is that they have very poor low speed ...
8
votes
5answers
18k views

What is profile drag?

I know about induced drag, parasite drag, form drag, skin drag, wave drag, and interference drag. But I don't encounter the term profile drag often, and I can't find a good definition of it. Is ...
13
votes
2answers
25k views

What is the method to calculate a finite wing's lift from its sectional airfoil shape?

I am struggling to get my head around a concept that I believe should be fairly simple to understand. Lift versus drag and AoA data of many airfoils are freely available, for instance the NACA 4-...
16
votes
4answers
4k views

Why are swept wings better for breaking the sound barrier?

I'm told that swept wings perform better when an aircraft is trying to break the sound barrier. I was wondering why that would be?
9
votes
2answers
2k views

What causes the reduction in speed across the shockwave?

Wherever I read about shock waves, it is mentioned that there is a reduction in speed across the shock wave. Can someone please explain what happens at the molecular level, i.e. the physics of the ...
7
votes
2answers
3k views

What are the conditions for an airfoil to be a “thin airfoil?”

I know about the theory differences between regular airfoils and thin airfoils, but is there any condition for saying a given airfoil can be analyzed as if it is thin? The extreme case of infinitely ...
12
votes
2answers
2k views

Can a supersonic plane use a subsonic wing if the nosecone shock produces subsonic airflow around the wing?

A supersonic plane will produce shock waves off the nose cone, as seen below: These oblique shocks reduce the speed of the air that the wing experiences. If the plane is at a low enough Mach number, ...
2
votes
2answers
3k views

How can the zero-lift drag coefficient (parasitic drag) be calculated?

Consider a 3-D wing made from an arbitrary airfoil, say a NACA0012 airfoil. The wing has a trapezoidal shape, with a fixed span, root chord, and tip chord. Also, assume that the wing loading is known ...
3
votes
5answers
732 views

Is wing sweep needed on supersonic aircraft?

Area rule states that bodies with the same crossectional area distribution have the same drag. Does that mean I could use a straight wing on mach 1.2 aircraft with performance as high as sweep winged ...
0
votes
3answers
6k views

Why does centre of pressure (drag?) move forward when transitioning from transonic to supersonic?

I am studying aerospace engineering at college and I am wondering why the centre of pressure moves forward when the aircraft changes from transonic flight to supersonic flight? Also, is centre of ...
1
vote
2answers
2k views

What is the pressure distribution around a supersonic wing?

In subsonic flight the lift manifests itself at 25% of chord, but shifts to 50% of chord when the airplane goes supersonic. Wondering about that made me think that the reason might be that there is ...
4
votes
1answer
1k views

Why does the aspect ratio of a wing become less important at supersonic speeds?

My understanding is that an increase in the aspect ratio (AR) of a supersonic wing won't increase the efficiency like it would for a subsonic wing. If the subsonic induced drag is: $C_{D_i} = (C_L^2)...
2
votes
2answers
2k views

What are the effects of camber location in an airfoil?

Am I correct to assume that for a low speed aircraft, the location of the camber in the MAC's airfoil will correspond with the aerodynamic center? Also, does that affect the moment coefficient? And ...
3
votes
1answer
2k views

How does downwash change relative wind? [duplicate]

I have a question regarding the production mechanism of induced drag. I understand the downwash aft of the trailing edge (steaming from wingtip vortices) causes the induced drag by changing the ...
5
votes
1answer
206 views

How does a delta wing deal with supersonic boundary separation?

The question Why most of the supersonic or fighter aircraft use all-moving control surfaces? emphasis the importance of all moving stabilator for supersonic aircraft. Many supersonic aircrafts ...

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