All Topics  
Turboshaft

 

 
   Email Print
   Bookmark   Link
 

 

Turboshaft
 
 
  Topics Turboshaft Topic Home

A turboshaft engine is a form of gas turbine
Gas turbine

A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between....
 which is optimized to produce shaft power, rather than jet thrust. In principle a turboshaft engine is similar to a turbojet
Turbojet

Turbojets are the oldest kind of general purpose jet engines. Two engineers, Frank Whittle in the United Kingdom and Hans von Ohain in Germany, developed the concept independently into practical engines during the late 1930s, although credit for the first turbojet is given to Whittle who submitted the first proposal and held a UK patent that...
, except the former features additional turbine expansion to extract heat energy from the exhaust and convert it into output shaft power.

Turboshaft engines are commonly used in applications which require a sustained high power output, high reliability, small size and light weight.






Discussion
Ask a question about 'Turboshaft'
Start a new discussion about 'Turboshaft'
Answer questions from other users
Full Discussion Forum



Recent Posts

What is the difference between the piston type engine and the turboshaft engine and why turboshaft e...








Encyclopedia


Turboshaft Operation
A turboshaft engine is a form of gas turbine
Gas turbine

A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between....
 which is optimized to produce shaft power, rather than jet thrust. In principle a turboshaft engine is similar to a turbojet
Turbojet

Turbojets are the oldest kind of general purpose jet engines. Two engineers, Frank Whittle in the United Kingdom and Hans von Ohain in Germany, developed the concept independently into practical engines during the late 1930s, although credit for the first turbojet is given to Whittle who submitted the first proposal and held a UK patent that...
, except the former features additional turbine expansion to extract heat energy from the exhaust and convert it into output shaft power.

Turboshaft engines are commonly used in applications which require a sustained high power output, high reliability, small size and light weight. These include helicopter
Helicopter

A helicopter is an aircraft that is Lift and propelled by one or more horizontal plane Helicopter rotors, each rotor consisting of two or more rotor blades....
s, auxiliary power unit
Auxiliary power unit

An auxiliary power unit is a device on a vehicle whose purpose is to provide energy for functions other than propulsion. Different types of APU are found on aircraft, as well as on some large ground vehicles....
s, boat
Boat

A boat is a watercraft of modest size designed to float or plane on water, and provide transport over it. Usually this water will be inland or in protected coastal areas....
s and ship
Ship

A ship is a large watercraft that floats on water. Ships are generally distinguished from boats based on size. Ships may be found on lakes, seas, and rivers and they allow for a variety of activities, such as the ferry or cargo ships, fishing, cruise ship, Coast guard, and warship....
s, tank
Tank

A tank is a Continuous track, armoured fighting vehicle designed for front-line combat which combines operational mobility and Military tactics Offensive and defence capabilities....
s, hovercraft
Hovercraft

A hovercraft, or air-cushion vehicle , is a craft , designed to travel over any smooth surface supported by a cushion of slowly moving, high-pressure air, ejected downwards against the surface below, and contained within a "skirt." Hovercraft are used throughout the world as a method of specialized transport where ever there is the nee...
, and sometimes stationary equipment.

Overview

A turboshaft engine contains a gas generator section, consisting of the compressor
Gas compressor

A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe ....
, combustion chambers with ignitors and fuel nozzles, and one or more stages of turbine
Turbine

A turbine is a rotary engine that extracts energy from a fluid flow. Claude Burdin coined the term from the Latin turbo, or vortex, during an 1828 engineering competition....
. The gas generator's function is to create the hot expanding gases to drive the power section, which consists of more stages of turbines, a gear reduction system, and shaft output. Depending on the design, the engine accessories may be driven either by the gas generator or by the power section.

In most designs the gas generator and power section are mechanically separate so that they may each rotate at different speeds appropriate for the conditions. This is 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 forego the weight and cost of complex multi-ratio transmissions
Transmission (mechanics)

Using the principle of mechanical advantage, transmissions provide a speed-torque conversion from a higher speed motor to a slower but more forceful output or vice-versa....
 and clutch
Clutch

A clutch is a mechanism for transmitting rotation, which can be engaged and disengaged. Clutches are useful in devices that have two rotating shafts....
es.

The general layout of a turboshaft is similar to that of a turboprop
Turboprop

A turboprop engine is a type of aircraft engine that uses a gas turbine to drive a propeller. The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller....
. The main difference is that a turboprop is structurally designed to support the loads created by a rotating propeller
Propeller

A propeller is a type of fan which transmits power by converting rotational motion into thrust. It can be used to drive an fixed-wing aircraft, ship, or the fluid within a pump....
, as the propeller is not attached to anything but the engine itself. In contrast, turboshaft engines usually drive a transmission which is not structurally attached to the engine. The transmission is attached to the vehicle structure and supports the loads created instead of the engine. However, in practice many of the same engines are built in both turboprop and turboshaft versions, with only minor differences.

History

The first true turboshaft engine was built by the French
France

France , officially the French Republic , is a country whose Metropolitan France is located in Western Europe and that also comprises various Overseas departments and territories of France....
 engine firm Turbomeca
Turbomeca

Turbomeca is a France manufacturer of low- and medium-power gas turbine turboshaft engines for helicopters. The company also produces gas turbine engines for aircraft and missiles, as well as turbines for land, industrial and marine applications....
, led by the founder, Joseph Szydlowski
Joseph Szydlowski

Joseph Szydlowski , was a Jewish-Polish-French-Israeli aircraft engine designer who founded Turbomeca in France....
. 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
Turbomeca Artouste

The Turbomeca Artouste was an early French turboshaft engine, first run in 1947 in aviation. 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....
, which was widely used on the Aérospatiale Alouette II
Aérospatiale Alouette II

The Alouette II is a light helicopter originally manufactured by Sud Aviation and later A?rospatiale, both of France. The Alouette II was the first production helicopter to use a gas turbine instead of a conventional heavier piston engine....
 and other helicopters.

See also


  • Jet engine performance
    Jet engine performance

    This article describes how jet engine performance is estimated during the design phase. Similar techniques are used once the engine has been built and is being tested, except the performance of individual components, rather than being assumed, is inferred from test measurements ....
  • Jet aircraft
    Jet aircraft

    A jet aircraft is an aircraft propelled by jet engines. Jet aircraft fly much faster than propeller-powered aircraft and at higher altitudes -- as high as 10,000 to 15,000 meters ....
  • Jetboat
    Jetboat

    A jetboat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses a propeller in the water below or behind the boat, a jetboat draws the water from under the boat into a pump-jet inside the boat, then expels it through a nozzle at the stern....
  • Turbofan
    Turbofan

    A turbofan is a type of aircraft engine consisting of a ducted fan which is powered by a gas turbine. Part of the airstream from the ducted fan passes through the gas turbine core, providing oxygen to burn fuel to create power....
  • Turbojet
    Turbojet

    Turbojets are the oldest kind of general purpose jet engines. Two engineers, Frank Whittle in the United Kingdom and Hans von Ohain in Germany, developed the concept independently into practical engines during the late 1930s, although credit for the first turbojet is given to Whittle who submitted the first proposal and held a UK patent that...
  • Turboprop
    Turboprop

    A turboprop engine is a type of aircraft engine that uses a gas turbine to drive a propeller. The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller....
  • Jet engine
    Jet engine

    A jet engine is a reaction engine that discharges a fast moving jet of fluid to generate thrust in accordance with Isaac Newton Newton's laws of motion....
  • Ramjet
    Ramjet

    A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of jet engine using the engine's forward motion to compress incoming air, without a rotary compressor....
  • Spacecraft propulsion
    Spacecraft propulsion

    Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research....
  • Supercharger
    Supercharger

    A supercharger is an air Gas compressor used for forced induction of an internal combustion engine. The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally-aspirated engine, which allows more fuel to be provided and more work to be done per cycle, increasing the power output of the engine...
  • Turbocharger
    Turbocharger

    A turbocharger, or turbo, is a gas compressor used for forced induction of an internal combustion engine. Like a supercharger, the purpose of a turbocharger is to increase the mass of air entering the engine to create more power....
  • Gas turbine
    Gas turbine

    A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between....
  • Kurt Schreckling
    Kurt Schreckling

    Kurt Schreckling is a German people who pioneered home constructed turbojet engines for model aircraft.His design was constructed using hand tools, and has a wooden compressor and a bent metal gas turbine....
     who built practical jet engines for model aircraft
  • MTT Turbine SUPERBIKE
    MTT Turbine SUPERBIKE

    MTT Turbine SUPERBIKE, also known as Y2K Turbine SUPERBIKE, is the world's second wheel driven motorcycle powered by a turbine engine, created by Ted McIntyre of Marine Turbine Technologies...
    , a turboshaft-powered superbike


External links

  • Wikibooks: Jet propulsion