5
$\begingroup$

What would you expect the typical lift force and coefficient of lift and drag to be for a A320 at cruise?

Considering flight at 36,000 ft, mass approximately 72 tons, velocity 230 m/s with a surface area of 122.6 m² and density 0.366 kg/m³.

The results I've calculated seem a little high, CL=0.666 and L=724 kN

Improve this question
$\endgroup$
5
$\begingroup$

In s/l flight, weight and lift are practically equal, so –if those are metric tons– the lift will be 72000 x 9,8 = 705600 N. Now, concerning the CL, we may solve for CL the expression for lift:

$C_L = \frac{2 · L}{\rho V^2 S } $

$C_L = \frac{2\cdot9.8\cdot72000} { 0.366 · 230^2 · 122.6 }$

$C_L = 0.595$

Now, assuming a L/D of 15, the CD = 0,594/15 = 0,039

Improve this answer
$\endgroup$
3
  • $\begingroup$ DeltaLima, I used newtons... Concerning the '2', perhaps I forgot to put it, but the end calculation was right... $\endgroup$ – xxavier Mar 30 '17 at 13:12
  • 1
    $\begingroup$ You're right. It was my mistake, if only when writing the answer down... Thanks... $\endgroup$ – xxavier Mar 30 '17 at 13:41
  • $\begingroup$ Firstly, thanks you for your reply. It's starting to become more clear now. From my CFD analysis, my modelled wing (only starboard hand) generates 369,000n of lift, which seems more plausible if the entire airframe is producing approximately 705600n. My model of course omits the flap cowlings and engine, so I'd expect the lift to be slightly higher. $\endgroup$ – simon ferguson Mar 30 '17 at 22:24

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.