A turboshaft engine is a form of gas turbine that is optimized to produce shaft horsepower rather than jet thrust . In concept, turboshaft engines are very similar to turbojets , with additional turbine expansion to extract heat energy from the exhaust and convert it into output shaft power. They are even more similar to turboprops , with only minor differences, and a single engine is often sold in both forms.
12-451: The Honeywell T55 (formerly Lycoming ; company designation LTC-4 ) is a turboshaft engine used on American helicopters and fixed-wing aircraft (in turboprop form) since the 1950s, and in unlimited hydroplanes since the 1980s. As of 2021, more than 6,000 of these engines have been built. It is produced by Honeywell Aerospace , a division of Honeywell based in Phoenix, Arizona, and
24-604: A gas turbine engine. (Most tanks use reciprocating piston diesel engines.) The Swedish Stridsvagn 103 was the first tank to utilize a gas turbine as a secondary, high-horsepower "sprint" engine to augment its primary piston engine's performance. The turboshaft engines used in all these tanks have considerably fewer parts than the piston engines they replace or supplement, mechanically are very reliable, produce reduced exterior noise, and run on virtually any fuel: petrol (gasoline), diesel fuel , and aviation fuels. However, turboshaft engines have significantly higher fuel consumption than
36-637: The Sikorsky CH-53E Super Stallion uses three General Electric T64 at 4,380 hp each. The first gas turbine engine considered for an armoured fighting vehicle, the GT 101 which was based on the BMW 003 turbojet, was tested in a Panther tank in mid-1944. The first turboshaft engine for rotorcraft was built by the French engine firm Turbomeca , led by its founder Joseph Szydlowski . In 1948, they built
48-445: The 'gas generator' and the 'power section'. The gas generator consists of the compressor , combustion chambers with ignitors and fuel nozzles , and one or more stages of turbine . The power section consists of additional stages of turbines, a gear reduction system, and the shaft output. The gas generator creates the hot expanding gases to drive the power section. Depending on the design, the engine accessories may be driven either by
60-842: The UK, Hindustan Aeronautics Limited in India, and developed by Continental CAE in the US as the Continental T51 . Two major versions of the Artouste were produced. The Artouste II family, mainly used in the Aérospatiale Alouette II helicopter, had a one-stage centrifugal compressor and a two-stage turbine, with gearbox-limited power of 300 kW (400 hp). The Artouste III family, mainly used in Aérospatiale's Alouette III and Lama helicopters, had
72-451: The diesel engines that are used in the majority of modern main battle tanks. Turbomeca Artouste The Turbomeca Artouste is an early French turboshaft engine, first run in 1947. Originally conceived as an auxiliary power unit (APU), it was soon adapted to aircraft propulsion, and found a niche as a powerplant for turboshaft-driven helicopters in the 1950s. Artoustes were licence-built by Bristol Siddeley (formerly Blackburn ) in
84-408: The first French-designed turbine engine, the 100-shp 782. Originally conceived as an auxiliary power unit , it was soon adapted to aircraft propulsion, and found a niche as a powerplant for turboshaft-driven helicopters in the 1950s. In 1950, Turbomeca used its work from the 782 to develop the larger 280-shp Artouste , which was widely used on the Aérospatiale Alouette II and other helicopters. This
96-452: The gas generator or by the power section. In most designs, the gas generator and power section are mechanically separate so they can each rotate at different speeds appropriate for the conditions, referred to as a ' free power turbine '. A free power turbine can be an extremely useful design feature for vehicles, as it allows the design to forgo the weight and cost of complex multiple-ratio transmissions and clutches . An unusual example of
108-458: The power output of the engine. Related development Comparable engines Related lists Turboshaft Turboshaft engines are commonly used in applications that require a sustained high power output, high reliability, small size, and light weight. These include helicopters , auxiliary power units , boats and ships , tanks , hovercraft , and stationary equipment. A turboshaft engine may be made up of two major parts assemblies:
120-736: The turboshaft principle is the Pratt & Whitney F135 -PW-600 turbofan engine for the STOVL Lockheed F-35B Lightning II – in conventional mode it operates as a turbofan, but when powering the Rolls-Royce LiftSystem , it switches partially to turboshaft mode to send 29,000 horsepower forward through a shaft and partially to turbofan mode to continue to send thrust to the main engine's fan and rear nozzle. Large helicopters use two or three turboshaft engines. The Mil Mi-26 uses two Lotarev D-136 at 11,400 hp each, while
132-633: Was following the experimental installation of a Boeing T50 turboshaft in an example of the Kaman K-225 synchropter on December 11, 1951, as the world's first-ever turboshaft-powered helicopter of any type to fly. The T-80 tank, which entered service with the Soviet Army in 1976, was the first tank to use a gas turbine as its main engine. Since 1980 the US Army has operated the M1 Abrams tank, which also has
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#1732854586690144-892: Was originally designed by the Turbine Engine Division of Lycoming Engines in Stratford, Connecticut , as a scaled-up version of the smaller Lycoming T53 . The T55 serves as the engine on several major applications including the CH-47-Chinook, the Bell 309, and the Piper PA-48 Enforcer. The T55 also serves as the core of the Lycoming ALF 502 turbofan . Since the T55 was first developed, progressive increases in airflow , overall pressure ratio, and turbine inlet temperature have more than tripled
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