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How do you calculate the lift to drag ratio of an aircraft?
Lift-to-drag ratio
- In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the amount of lift generated by a wing or vehicle, divided by the aerodynamic drag it creates by moving through air.
- The term is calculated for any particular airspeed by measuring the lift generated, then dividing by the drag at that speed.
How do you calculate lift off distance?
The takeoff distance consists of two parts, the ground run, and the distance from where the vehicle leaves the ground to until it reaches 50 ft (or 15 m). The sum of these two distances is considered the takeoff distance. (Note: sometimes a 35 ft altitude is used).
What is the lift of a vertical takeoff?
When the craft takes off vertically, its C D is high and its C L is zero. “Lift” (vertical takeoff) would be the aircraft weight + drag at the desired rate of ascent. The aircraft will accelerate upwards until thrust (vertically) = weight + drag.
How is the drag coefficient of an aircraft calculated?
The aircraft will accelerate upwards until thrust (vertically) = weight + drag. Drag coefficient can be modelled from flat plate or other appropriate flat shape (top view of the aircraft would be best), but keep in mind the ascent rate will be relatively slow and the majority of engine power will be used to overcome weight.
Can a VTOL aircraft have a fixed wing?
VTOL aircraft simply do not use their wings at all for lift off. Power/thrust requirements considered, a STOL may be a happy compromise. Since you listed it as a quadcopter with a fixed wing, I’m going to assume (at least in the takeoff/landing stage) that the propulsors are perpendicular to your wing.
What should thrust over weight ratio be for VTOL?
On the other hand, some references, 16 suggested to use thrust over weight ratio between 1.2 and 1.5 for VTOL with good results.