Choose four to read about in some detail. Write a brief summary (one paragraph max for each) and compare/contrast some of their key performance metrics and intended use cases.
Consider a commercial transport with the following parameters:
| wing span (\(b\)) | 61 m |
| reference wing area (\(S_{ref}\)) | 325 m\(^2\) |
| mass | 200,000 kg |
| Mach number | 0.82 |
| zero lift (parasitic) drag coefficient (\({C_D}_p\)) | 0.01 |
| Oswald efficiency factor (\(e\)) | 0.7 |
Find the optimal altitude to fly at that will maximize specific range, which is the distance flown per unit weight of fuel burn. Assume a constant Mach number and steady, level flight. Later in the semester we will learn more about propulsion, but for now we will ignore changes in propulsive efficiency with altitude. Using that assumption implies that we should maximize the following metric:
\[V \frac{L}{D}\]where \(V\) is the flight speed.
We haven’t covered all of drag yet, so for now here is the equation you should use (the relevant symbols are noted in the table above):
\[D = {C_D}_p q S_{ref} + \frac{L^2}{q \pi b^2 e}\]