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Schlumpf Drives are primarily used as an alternative to multiple chainrings. Four models are currently produced, with differing ratios from pedal revolutions to chainwheel revolutions. Speed Drive, this allows a 65% increase in the final drive (ratio 1.65). High Speed Drive, this allows a 150% increase in the final drive (ratio 2.5).
The efficiency of internal combustion engines depends on several factors, the most important of which is the expansion ratio. For any heat engine the work which can be extracted from it is proportional to the difference between the starting pressure and the ending pressure during the expansion phase.
In mechanical engineering, mechanical efficiency is a dimensionless ratio that measures the efficiency of a mechanism or machine in transforming the power input to the device to power output. A machine is a mechanical linkage in which force is applied at one point, and the force does work moving a load at another point.
The capstan equation [1] or belt friction equation, also known as Euler–Eytelwein formula [2] (after Leonhard Euler and Johann Albert Eytelwein), [3] relates the hold-force to the load-force if a flexible line is wound around a cylinder (a bollard, a winch or a capstan).
The advance ratio is critical for determining the efficiency of a propeller. At different advance ratios, the propeller may produce more or less thrust. Engineers use this ratio to optimize the design of the propeller and the engine, ensuring that the vehicle operates efficiently at its intended cruising speed, see propeller theory .
Low aspect ratio compressor blades, with their better efficiency both aerodynamically and structurally, were introduced in the 1950s turbojet the Tumansky R-11, and subsequently examples of wide chord fan blades introduced in 1983 in the Garrett TFE731-5 [72] and in 1984 in the RB211-535E4 [73] and Pratt & Whitney Canada JT15D-5. [74]
Vehicle Liftoff Mass Payload Mass to LEO Mass ratio Payload fraction Falcon 9 Block 5: 549,054 kg + 22,800 kg 22,800 kg 25.1 3.99% Proton-M: 705,000 kg + 23,000 kg
A consumption map or efficiency map [1] is a chart that displays the brake-specific fuel consumption of an internal combustion engine at a given rotational speed and mean effective pressure, in grams per kilowatt-hour (g/kWh). The map contains each possible condition combining rotational speed and mean effective pressure.