Need to find L/D ratio for F117

[vchi]

Homework Statement

I was trying to look for an L/D ratio published on the web for the F-117 Nighthawk, and I can't seem to find it; need it for a class project. Since I couldn't find it, I wanted to try calculating myself, but still can't seem to find $$C_l$$ or $$C_d$$ without some sort of paywall on research papers, which I'm not even sure has them in it.

Relevant Equations

$$L = \frac{1}{2} C_{l} \cdot \rho v^2 A$$ ........................ lift equation

$$D = \frac{1}{2} C_{d} \cdot \rho v^2 A$$ ...................... drag equation

I was trying to look for an L/D ratio published everywhere on the web and I can't seem to find it for our project. Since I couldn't find it, I wanted to try calculating myself. Can't seem to find $$C_l$$ or $$C_d$$ though without some sort of paywall on research papers.

So L/D would just be:

$$\frac{L}{D} = \frac{C_l}{C_d}$$

or would the effective area be different for L and D, where L is the area of the top/bottom view of the plane, and D is the area of the front/back view? If this were the case then L and D would have to be determined separately.

The problem is that I'm still missing the C_l and C_d, for the F117, to complete this calculation. Does anyone happen to have access to this? Or is it top secret or something? Been scouring the internet for a couple hours now trying to look for it.

 

[fresh_42]

There are online calculators for it:
https://www.fxsolver.com/solve/
Maybe here (F117 A on page 650):
http://www.ingaero.uniroma1.it/users/ingaero/joomla/attachments/683_filippone.pdf
and Wikipedia has a formula for an estimation:
https://en.wikipedia.org/wiki/Zero-lift_drag_coefficient

 

[Klystron]

Here are the public specs. While officially inactive, F-117A flight data may not be available. For extra credit you can show the Nighthawk is a bomber, not a fighter.

Given the area measurements and flight regime you can estimate average lift. Keep in mind the F-117A was designed for stealth -- reduced radar cross section -- not elegant flight or speed. It is unstable in pitch, roll, and yaw; particularly at low speeds, controlled by on-board computers (fly-by-wire). While calculating lift, remember Lockheed designed the Nighthawk as a 'lifting body' with the fuselage contributing as well as the wings.