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In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under given flight conditions. The L/D ratio for any given body will vary according to these flight conditions.
This vehicle can be considered an AAMV, since it has two planing sponsons separated by a wing section. Therefore, it is a vehicle with aerodynamic and hydrodynamic surfaces, designed to obtain aerodynamic and hydrodynamic lift. In his article Ward presented the results of some trials: the KUDU II was able to run at 78 knots (144 km/h).
The term drag area derives from aerodynamics, where it is the product of some reference area (such as cross-sectional area, total surface area, or similar) and the drag coefficient. In 2003, Car and Driver magazine adopted this metric as a more intuitive way to compare the aerodynamic efficiency of various automobiles.
For conventional fixed-wing aircraft with moderate aspect ratio and sweep, Oswald efficiency number with wing flaps retracted is typically between 0.7 and 0.85. At supersonic speeds, Oswald efficiency number decreases substantially. For example, at Mach 1.2 Oswald efficiency number is likely to be between 0.3 and 0.5. [1]
Thus, a long, narrow wing has a high aspect ratio, whereas a short, wide wing has a low aspect ratio. [ 1 ] Aspect ratio and other features of the planform are often used to predict the aerodynamic efficiency of a wing because the lift-to-drag ratio increases with aspect ratio, improving the fuel economy in powered airplanes and the gliding ...
By proper shaping of the car's underside, the air speed there could be increased, lowering the pressure and pulling the car down onto the track. His test vehicles had a Venturi-like channel beneath the cars sealed by flexible side skirts that separated the channel from above-car aerodynamics. He investigated how flow separation on the ...
Automotive aerodynamics differs from aircraft aerodynamics in several ways: The characteristic shape of a road vehicle is much less streamlined compared to an aircraft. The vehicle operates very close to the ground, rather than in free air. The operating speeds are lower (and aerodynamic drag varies as the square of speed).
The aerodynamic setup for a car can vary considerably between race tracks, depending on the length of the straights and the types of corners. Because it is a function of the flow of air over and under the car, downforce increases with the square of the car's speed and requires a certain minimum speed in order to produce a significant effect.