Linked Questions

1
vote
1answer
218 views

Why is subsonic lift at 25% of chord? [duplicate]

I pretty much understand the way a wing works and the different ways of explaining it, what I don´t understand is why the lift on a subsonic wing manifest itself at the 25% chord.... The 50% chord ...
0
votes
1answer
298 views

Why is the Aerodynamic Centre not affected by changes in Angle of Attack? [duplicate]

I understand that the Aerodynamic Centre (AC) is the point in the aircraft where the pitching moment never changes with a change in Angle of Attack (AoA). My understanding of the Centre of Pressure (...
5
votes
1answer
7k views

Where is the best center of gravity?

I'm designing a plane, and I have a question. What is the best place for the center of gravity, relative to the center of lift? I've heard that it's best put just behind the center of lift, but I ...
4
votes
3answers
2k views

Why do tailplanes provide down force, if not for longitudinal static stability?

We can see that most conventional aircraft have their horizontal tail surfaces arranged to provide a down force. This question asks if that is required for static longitudinal stability, and the ...
3
votes
3answers
4k views

What is the physical meaning of Mean Aerodynamic Chord?

I have not been able to find a consistent definition of what it really is. I have come across definitions such as: "Physically, MAC is the chord of a rectangular wing, which has the same area, full ...
3
votes
2answers
7k views

How does centre of pressure change with angle of attack?

I've been given the distance of centre of pressure from the leading edge with a certain angle of attack and was wondering if it's possible to calculate the new position when the angle of attack ...
8
votes
1answer
874 views

Are the vortex generators on the Cessna Caravan necessary and sufficient for safety of flight?

I've been doing some reading about the C208B (Cessna Caravan) in prep for my new job flying cargo; I came across this article which (as far as I can tell) is a transcription of litigation surrounding ...
5
votes
2answers
3k views

Why do we calculate the pitching moment coefficient about quarter chord point?

Why do we calculate the pitching moment coefficient about quarter chord point, when force and moment system can be transferred to any convenient point?
0
votes
3answers
5k 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 ...
4
votes
1answer
841 views

Is setting elevator to certain angle equal to trimming the horizontal stabilizer?

(I was trying to understand the longitudinal stability of aircraft and how it is related to elevator) If I pull the stick back by, say 2 inches, will it have the same affect as trimming the ...
1
vote
1answer
2k views

How can I calculate effective wingspan of a high aspect ratio model airplane?

I've heard of people talking of wingspan and effective wingspan. Considering: L = Lift Coefficient . 1/2 Rho . Velocity ^ 2 . Surface Area, I understand that tip ...
1
vote
1answer
3k views

Why should the centre of mass be ahead of the centre of pressure?

Why is the centre of mass located ahead of the centre of pressure? And what would happen if centre of mass would be too close or too far away from the centre of pressure?
2
votes
2answers
1k 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 ...
0
votes
1answer
769 views

Which moments are acting on a flying airplane?

I would like to ask some clarifying questions regarding the moments acting on a flying airplane. My understanding is that there are following force: Weight (pointing down and applied to the CG of ...
3
votes
1answer
466 views

Why is the numerically determined location of the center of pressure inaccurate near Cl = 0?

I am working on an assignment and I need to calculate the center of pressure of an airfoil, through a numerical method (the panel method). I am getting a weird result because it gives its position on ...

15 30 50 per page