Turbocharger
A turbocharger (technically a turbosupercharger), colloquially known as turbo, is a turbine-driven, forced induction device that increases an internal combustion engine's power output by forcing extra compressed air into the combustion chamber.[1][2]This improvement over a naturally aspirated engine's power output is because the compressor can force more air—and proportionately more fuel—into the combustion chamber than atmospheric pressure (and for that matter, ram air intakes) alone.
Manufacturers commonly use turbochargers in trucks, cars, trains, aircraft, and construction-equipment engines. They are most often used with Otto cycle and diesel cycle internal combustion engines.
Forced induction dates back to the late 19th century, when Gottlieb Daimler patented the technique of using a gear-driven pump to force air into an internal combustion engine in 1885.[3]
The 1905[4] patent by Alfred Büchi, a Swiss engineer working at Gebrüder Sulzer (now simply called Sulzer) is often considered the birth of the turbocharger.[5][6] This patent was for a compound radial engine with an exhaust-driven axial flow turbine and compressor mounted on a common shaft.[7][8] The first prototype was finished in 1915 with the aim of overcoming the power loss experienced by aircraft engines due to the decreased density of air at high altitudes.[9][10] However, the prototype was not reliable and did not reach production.[9] Another early patent for turbochargers was applied for in 1916 by French steam turbine inventor Auguste Rateau, for their intended use on the Renault engines used by French fighter planes.[7][11] Separately, 1917 testing by the American National Advisory Committee for Aeronautics and Sanford Alexander Moss showed that a turbocharger could enable an engine to avoid any power loss (compared with the power produced at sea level) at an altitude of up to 4,250 m (13,944 ft) above sea level.[7] The testing was conducted at Pikes Peak in the United States using the V12 Liberty aircraft engine.[11]
The first commercial application of a turbocharger was in 1925, when Alfred Büchi successfully installed turbochargers on ten-cylinder diesel engines, increasing the power output from 1,300 to 1,860 kilowatts (1,750 to 2,500 hp).[12][13][14] This engine was used by the German Ministry of Transport for two large passenger ships called the "Preussen" and "Hansestadt Danzig". The design was licensed to several manufacturers and turbochargers began to be used in marine, railcar and large stationary applications.[10]
Turbochargers were used on several aircraft engines during World War II, beginning with the Boeing B-17 Flying Fortress in 1938, which used turbochargers produced by General Electric.[7][15] Other early turbocharged airplanes included the B-24 Liberator, P-38 Lightning, P-47 Thunderbolt and the experimental Focke-Wulf Fw 190 prototypes.
