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The Corvo Precision Payload Delivery System (PPDS) is a small aerial drone originally intended for logistics, weighs 2.4 kg (5.3 lb) empty, and deliveries payloads of up to 3 kilograms (6.6 lb). [1] The airframe is made of waxed foamcore (foamboard) and the drone is supplied as a self-assembly flatpack, complete with a tablet-PC control centre ...
1871 Planophore A Farman MF.11, showing the classic Farman configuration with engine between tail booms Buhl A-1 Autogyro, the first pusher autogyro The post-WWII Convair B-36 was unusual in its size, era, number of engines, and combining both propeller and jet propulsion, with six radial piston and four jet engines Typical of many UAVs, the General Atomics MQ-9 Reaper has a propeller at the ...
Matching the propeller load with motor torque: One of the more difficult design problem of underwater thrusters is to match the propeller load line with the motor power line. If it does not happen the overall efficiency of the thruster will fall well below maximum or only a small percentage of motor power will be used.
A 6-bladed Hamilton Standard 568F propeller on an ATR 72 short-haul airliner. Lowry [27] quotes a propeller efficiency of about 73.5% at cruise for a Cessna 172.This is derived from his "Bootstrap approach" for analyzing the performance of light general aviation aircraft using fixed pitch or constant speed propellers.
A constant-speed propeller is a variable-pitch propeller that automatically changes its blade pitch in order to maintain a chosen rotational speed, regardless of the operational conditions of the aircraft. This is achieved by use of a constant-speed unit (CSU) or propeller governor, which automatically changes the propeller's blade pitch.
It has no moving parts other than the rotors, motors and transmissions, and hence it requires very low maintenance. The use of carbon-fibre has resulted in a light weight of 1.5 kg (3 lb), which makes the Netra very portable. [11] A backpack case allows operators to carry the system to field locations to serve as the base station.
Among the designs he tried was the Oehmichen No. 2, which employed four two-blade rotors and eight propellers, all driven by a single engine. The angle of the rotor blades could be varied by warping. Five of the propellers, spinning in the horizontal plane, stabilized the machine laterally. Another propeller was mounted at the nose for steering.
Turboprop, turboshaft and turbofan engines have additional turbine stages to drive a propeller, bypass fan or helicopter rotor. In a free turbine the turbine driving the compressor rotates independently of that which powers the propeller or helicopter rotor. Cooling air, bled from the compressor, may be used to cool the turbine blades, vanes ...