due 10/30/2024 before midnight via Learning Suite 25 possible points
A transport aircraft has the following properties:
| span | 50 m |
| Sref | 300 m\(^2\) |
| CDp | 0.01 |
| Oswald efficiency | 0.7 |
| altitude | 35,000 ft |
| take-off mass | 200,000 kg |
| fuel burned | 60,000 kg |
| specific fuel consumption | 0.55 hr\(^{-1}\) |
| \(M_{cc}\) | 0.75 |
a) Plot the lift-to-drag ratio as a function of flight speed.
b) Plot the range (in km) as a function of flight speed.
For simplicity, we’ll assume constant altitude, and use a constant weight (average between takeoff and landing). Sidenote: this fuel represents that burned during a typical mission, but it would need to carry more for reserves. Because we are varying speed, and are at relatively high Mach numbers, it will be important to include compressibility drag (use 3.41 in the book). Be sure to use a wide enough range of speeds to clearly see the peaks (where each metric is maximized).
Consider two wings. Wing A is elliptically loaded. Wing B has a 5% larger span but with the same lift and same root bending moment (and so will not be elliptically loaded). What is the inviscid span efficiency of Wing B? What is the ratio of induced drag for Wing B divided by Wing A?
Create a flight envelope diagram of true air speed versus altitude for a small electric powered aircraft, i.e., an air taxi, with the specifications provided below.
| mass | 1,500 kg |
| CLmax | 1.1 |
| Sref | 20 m\(^2\) |
| max design speed | 75 m/s (EAS) |
| ceiling | 8,000 ft |