Aspect ratio n taper ratio

[Mohit_C]

As for the first question, this is what I recall:

L=1/2*rho*TAS^2*CL*S

Firstly you represent the graph of "coefficient of lift" against "angle of attack" and let's assume that it's a symmetrical aerofoil. In this case the curve starts at the origin. Take the following as an example:


Aspect ratio = wingspan / mean chord.

Now if we increase the aspect ratio (which can be achieved by either increasing wingspan or decreasing mean chord) the gradient of the graph "coefficient of lift" against "angle of attack" is increased, i.e. it becomes steeper, however the maximum coefficient of lift stays constant. As this occurs the critical angle of attack is decreased (i.e. it may fall to 10 degrees or below).

From this you can deduce that if we were to maintain a given angle of attack, say 10 degrees and we'd increase the aspect ratio, assuming all other factors remain constant and the new critical angle is above 10 degrees, we would now have a higher coefficient of lift for that same angle of attack. Therefore referring back to the lift formula, as coefficient of lift increases the overall lift increases.

Bear in mind that: wing surface = mean chord * wingspan
Let's assume that we change both mean chord and wingspan in such a way that the wing surface remains constant, otherwise we would have to consider the change in wing surface in the lift formula too.

Let someone correct me on this if possible.