A turboshaft engine is a form of gas turbine which is optimized to produce shaft power, rather than jet thrust. In principle a turboshaft engine is similar to a turbojet, except the former features additional turbine expansion to extract heat energy from the exhaust and convert it into output shaft power. Ideally there should be little residual thrust energy in the exhaust and the power turbine should be free to run at whatever speed the load demands.
OverviewThe general layout of a turboshaft is similar to that of a turboprop, the main difference being the latter produces some residual propulsion thrust to supplement that produced by the shaft driven propeller. Another difference is that with a turboshaft the main gearbox is part of the vehicle (e.g. helicopter rotor reduction gearbox), not the engine. Virtually all turboshafts have a "free" power turbine, although this is also generally true for modern turboprop engines. At a given power output, compared to the equivalent piston engine, a turboshaft is extremely compact and, consequently, lightweight.
UsesThe name turboshaft is most commonly applied to engines driving:
HistoryThe first true turboshaft engine was built by the French engine firm Turbomeca, led by the founder, Joseph Szydlowski. In 1948 they built the first French-designed turbine engine, the 100shp 782. In 1950 this work was used to develop the larger 280shp Artouste, which was widely used on the Aérospatiale Alouette II and other helicopters.
Modern enginesToday almost all engines are built so that power-take-off is independent of engine speed, using the free turbine stage. This has two advantages:
- It allows a helicopter rotor or propeller to spin at any speed instead of being geared directly to the compressor turbine.
- It allows the engine to be split into two sections, the "hot section" containing the majority of the engine, and the separate power-take-off, allowing the hot-section to be removed for easier maintenance.
- Jet Engine Performance
- Jet aircraft
- Jet Engine
- Spacecraft propulsion
- Gas turbine
- Kurt Schreckling who built practical jet engines for model aircraft
- MTT Turbine SUPERBIKE, a turboshaft-powered superbike
- Wikibooks: Jet
turboshaft in Arabic: محرك عمود دوران توربيني
turboshaft in Czech: Turbohřídelový motor
turboshaft in Korean: 터보샤프트
turboshaft in Italian: Turboalbero
turboshaft in Dutch: Turboshaft
turboshaft in Polish: Silnik turbowałowy
turboshaft in Chinese: 渦輪軸發動機