1
$\begingroup$

I am aware what the area rule states - my question is what is defined as "as smooth as possible area distribution" - Is there a formula for the curve?

$\endgroup$
4
$\begingroup$

Since Drag is proportional to S'', the key is to derive a shape that has a minimum S''.

The result is the Sears-Haack body.

The Sears–Haack body is the shape with the lowest theoretical wave drag in supersonic flow, for a given body length and given volume.

The area is given by:

$$ S(x) = \frac {16V}{3L\pi}[4x(1-x)]^{3/2} = \pi R_\text{max}^2[4x(1-x)]^{3/2}$$

And the radius is given by:

$$ r(x) = R_\text{max}[4x(1-x)]^{3/4} $$

enter image description here Image source

| improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.