Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Turboprop shopping experience:
1. Compare - without doubt the biggest advantage that the Turboprop offers shoppers today is the ability to compare thousands of Turboprop at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Turboprop? Wrong! If the Turboprop is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Turboprop then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Turboprop? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Turboprop and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Turboprop wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Turboprop then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Turboprop site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Turboprop, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Turboprop, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
, one of the most popular turboprop engines.A
turboprop engine is a type of
Gas turbine used in aircraft. Most of a turboprop engine's power is used to drive a
propeller, and the propellers used are very similar to the propellers used in
piston or reciprocating engine-driven aircraft (with the exception that turboprops usually use a constant velocity propeller).
A turboprop engine is similar to a
turbojet, but has additional stages in the
turbine to recover more power from the engine to turn the propeller. Turboprop engines are generally used on small or slow subsonic aircraft, but some aircraft outfitted with turboprops have cruising speeds in excess of 500
Knot (speed) (926 km/h, 575 mph).
In its simplest form, a turboprop consists of an intake,
compressor, combustor, turbine and a Air propulsion nozzle. Air is drawn into the intake and compressed by the compressor. Fuel is then added to the compressed air in the combustor. The hot combustion gases expand through the turbine. Part of the power generated by the turbine is used to drive the compressor. The rest goes through the reduction gearing to the propeller. Further expansion of the gases occurs in the propelling nozzle, where the gases exhaust to atmospheric pressure. The propelling nozzle provides a relatively small proportion of the thrust generated by a turboprop, the remainder comes from the conversion of shaft power to thrust in the propeller.
Turboprops are very efficient at modest flight speeds (below 450 mph), because the jet velocity of the propeller (and exhaust) is relatively low. Due to the high price of turboprop engines, they are mostly used where high performance Short-Takeoff and Landing (
STOL) capability and efficiency at modest flight speeds is required. In a civilian aviation context, the most common application of turboprop engines are small commuter aircraft.
turboprop, single engine, two seat
Trainer (aircraft) PZL-130 Orlik TC-I of Orlik Aerobatic Team
Technological aspects
In a turboprop much of the jet thrust is sacrificed in favor of shaftpower, which is obtained by extracting additional power (to that necessary to drive the compressor) from the turbine expansion process. While the power turbine may be integral with the gas generator section, many turboprops today feature a Free Power Turbine, on a separate coaxial shaft. This enables the propeller to rotate freely, independent of compressor speed. Owing to the additional expansion in the turbine system, the residual energy in the exhaust jet is fairly low. Consequently, the exhaust jet produces (typically) less than 10% of the total thrust, including that from the propeller.
Because the propeller is much larger in diameter than the power turbine, the tip speed of the propeller can become supersonic. To prevent this, a speed reduction gearbox is inserted between the power turbine and propeller shafts. The gearbox is part of the engine, whereas in a
turboshaft the (
helicopter) rotor reduction gearbox is remote from the engine.
Residual thrust on a turboshaft is avoided by further expansion in the turbine system and/or truncating and turning the exhaust through 180 degrees, to produce two opposing jets. Apart from the above, there is very little difference between a turboprop and a turboshaft.
While most modern
turbojet and turbofan engines use
axial-flow compressors, turboprop engines, because of their small size, usually contain at least one stage of centrifugal compressor. NOTE: it is difficult to manufacture robust blading for the rear stages of small axial-flow compressors.
Propellers lose efficiency as aircraft speed increases, so turboprops are normally not used on high-speed aircraft. However,
Propfan engines, which are very similar to turboprop engines, can cruise at flight speeds approaching
mach number 0.75. To increase the efficiency of the propellers, a mechanism can be used to alter the pitch, thus adjusting the pitch to the airspeed. The variable pitch propeller, also called controllable pitch propeller can also be used to generate negative thrust while decelerating on the runway. After an engine outage, the pitch can be adjusted to a vaning pitch, thus minimising the drag of the non-functioning propeller.
History
The world's first Turboprop was the 'Jendrassik Cs-1' designed by the
Hungary mechanical engineer
György Jendrassik. It was produced and tested in the Ganz Factory in Budapest between 1939 and 1942. It was planned to fit to the Varga RMI-1 X/H twin-engined reconnaissance bomber designed by László Varga in 1940, but the programme was cancelled. Jendrassik had also designed a small-scale 75 kW turboprop in 1937.
The first British turboprop engine was the
Rolls-Royce Limited Rolls-Royce Trent (turboprop), a converted Rolls-Royce Derwent fitted with reduction gear and a
Rotol 7 foot (length) 11
inch five-bladed propeller. Two Trents were fitted to Gloster Meteor
Serial number — the sole "Trent-Meteor" — which became the first relatively reliable turboprop powered aircraft. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Dart, which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years.
While the Soviet Union had the technology to create a jet powered strategic bomber comparable to Boeing's B-52 Stratofortress, they instead produced the
Tupolev Tu-95, which uses 8 contra-rotating propellers (two per nacelle) with supersonic tip speeds to achieve maximum cruise speeds in excess of 575 mph, faster than many of the first jet aircraft, and comparable to jet cruising speeds for most missions. The Bear would serve as their most successful long range combat and surveillance aircraft and symbol of Soviet power projection throughout the end of the 20th century. The USA would incorporate contra-rotating turboprop engines in two experimental tail-sitting VTOL and fighter aircraft, the
Convair XFY and the
Lockheed XFV, during the 1950s, but none would be adopted into service.
The first American turboprop was the General-Electric T-31. America skipped over turboprop airliners in favor of the Boeing 707, but the technology of the Lockheed L-188 Electra would be used in both the long-lived P-3 Orion as well as the classic C-130 Hercules, one of the most successful military aircraft ever, in terms of length of production. One of the most popular turboprop engines is the Pratt & Whitney Canada PT6 engine.
See also
, one of the most popular turboprop engines.A
turboprop engine is a type of
Gas turbine used in aircraft. Most of a turboprop engine's power is used to drive a propeller, and the propellers used are very similar to the propellers used in
piston or reciprocating engine-driven aircraft (with the exception that turboprops usually use a constant velocity propeller).
A turboprop engine is similar to a turbojet, but has additional stages in the turbine to recover more power from the engine to turn the propeller. Turboprop engines are generally used on small or slow subsonic aircraft, but some aircraft outfitted with turboprops have cruising speeds in excess of 500 Knot (speed) (926 km/h, 575
mph).
In its simplest form, a turboprop consists of an intake,
compressor,
combustor,
turbine and a
Air propulsion nozzle. Air is drawn into the intake and compressed by the compressor. Fuel is then added to the compressed air in the combustor. The hot combustion gases expand through the turbine. Part of the power generated by the turbine is used to drive the compressor. The rest goes through the reduction gearing to the propeller. Further expansion of the gases occurs in the propelling nozzle, where the gases exhaust to atmospheric pressure. The propelling nozzle provides a relatively small proportion of the thrust generated by a turboprop, the remainder comes from the conversion of shaft power to thrust in the propeller.
Turboprops are very efficient at modest flight speeds (below 450 mph), because the jet velocity of the propeller (and exhaust) is relatively low. Due to the high price of turboprop engines, they are mostly used where high performance Short-Takeoff and Landing (
STOL) capability and efficiency at modest flight speeds is required. In a civilian aviation context, the most common application of turboprop engines are small commuter aircraft.
turboprop, single engine, two seat Trainer (aircraft)
PZL-130 Orlik TC-I of Orlik Aerobatic Team
Technological aspects
In a turboprop much of the jet thrust is sacrificed in favor of shaftpower, which is obtained by extracting additional power (to that necessary to drive the compressor) from the turbine expansion process. While the power turbine may be integral with the gas generator section, many turboprops today feature a Free Power Turbine, on a separate coaxial shaft. This enables the propeller to rotate freely, independent of compressor speed. Owing to the additional expansion in the turbine system, the residual energy in the exhaust jet is fairly low. Consequently, the exhaust jet produces (typically) less than 10% of the total thrust, including that from the propeller.
Because the propeller is much larger in diameter than the power turbine, the tip speed of the propeller can become supersonic. To prevent this, a speed reduction gearbox is inserted between the power turbine and propeller shafts. The gearbox is part of the engine, whereas in a
turboshaft the (
helicopter) rotor reduction gearbox is remote from the engine.
Residual thrust on a turboshaft is avoided by further expansion in the turbine system and/or truncating and turning the exhaust through 180 degrees, to produce two opposing jets. Apart from the above, there is very little difference between a turboprop and a turboshaft.
While most modern
turbojet and turbofan engines use axial-flow compressors, turboprop engines, because of their small size, usually contain at least one stage of centrifugal compressor. NOTE: it is difficult to manufacture robust blading for the rear stages of small axial-flow compressors.
Propellers lose efficiency as aircraft speed increases, so turboprops are normally not used on high-speed aircraft. However,
Propfan engines, which are very similar to turboprop engines, can cruise at flight speeds approaching
mach number 0.75. To increase the efficiency of the propellers, a mechanism can be used to alter the pitch, thus adjusting the pitch to the airspeed. The variable pitch propeller, also called controllable pitch propeller can also be used to generate negative thrust while decelerating on the runway. After an engine outage, the pitch can be adjusted to a vaning pitch, thus minimising the drag of the non-functioning propeller.
History
The world's first Turboprop was the 'Jendrassik Cs-1' designed by the Hungary mechanical engineer György Jendrassik. It was produced and tested in the Ganz Factory in Budapest between 1939 and 1942. It was planned to fit to the Varga RMI-1 X/H twin-engined reconnaissance bomber designed by László Varga in 1940, but the programme was cancelled. Jendrassik had also designed a small-scale 75 kW turboprop in 1937.
The first British turboprop engine was the Rolls-Royce Limited
Rolls-Royce Trent (turboprop), a converted
Rolls-Royce Derwent fitted with reduction gear and a
Rotol 7 foot (length) 11
inch five-bladed propeller. Two Trents were fitted to
Gloster Meteor Serial number — the sole "Trent-Meteor" — which became the first relatively reliable turboprop powered aircraft. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Dart, which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years.
While the Soviet Union had the technology to create a jet powered strategic bomber comparable to Boeing's
B-52 Stratofortress, they instead produced the Tupolev Tu-95, which uses 8 contra-rotating propellers (two per nacelle) with supersonic tip speeds to achieve maximum cruise speeds in excess of 575 mph, faster than many of the first jet aircraft, and comparable to jet cruising speeds for most missions. The Bear would serve as their most successful long range combat and surveillance aircraft and symbol of Soviet power projection throughout the end of the 20th century. The USA would incorporate contra-rotating turboprop engines in two experimental tail-sitting VTOL and fighter aircraft, the Convair XFY and the Lockheed XFV, during the 1950s, but none would be adopted into service.
The first American turboprop was the General-Electric T-31. America skipped over turboprop airliners in favor of the Boeing 707, but the technology of the
Lockheed L-188 Electra would be used in both the long-lived P-3 Orion as well as the classic C-130 Hercules, one of the most successful military aircraft ever, in terms of length of production. One of the most popular turboprop engines is the Pratt & Whitney Canada PT6 engine.
See also
- Gas turbine
- Kurt Schreckling who built practical jet engines for model aircraft
- Propfan
- Jet engine
- Jet engine performance
- Jet aircraft
- Jetboat
- Ramjet
- Spacecraft propulsion
- Supercharger
- TP400-D6 a new turbo prop engine being developed for the Airbus A400M
- Turbocharger
- Turbofan
- Turbojet
- Turboshaft
Turboprop - Wikipedia, the free encyclopedia
A turboprop engine is a type of aircraft powerplant that uses a gas turbine engine to drive a propeller. The gas turbine is designed specifically for this application, with almost ...
AskOxford: turboprop
turboprop • noun a jet engine in which a turbine is used to drive a propeller. Perform another search of the Compact Oxford English Dictionary
turboprop - Hutchinson encyclopedia article about turboprop
Engine in which steam, water, gas, or air (see windmill) is made to spin a rotating shaft by pushing on angled blades, like a fan. There are two sets of blades, the stator (does ...
turboprop definition of turboprop in the Free Online Encyclopedia.
turboprop: see turbine turbine, rotary engine that uses a continuous stream of fluid (gas or liquid) to turn a shaft that can drive machinery. A water, or hydraulic, turbine is ...
Turboprop Engine
To move an airplane through the air, thrust is generated with some kind of propulsion system. Many low speed transport aircraft and small commuter aircraft use turboprop propulsion ...
Wren Turbines Ltd: Turboprop Range
Wren Turbines Ltd, World Leaders in Miniature Turbine Technology ... Our turboprop range consists of two engines. The Turboprop and the smaller 44 Turboprop
Charter Flights, Turbo Prop Aircraft, Private Plane Hire
Turboprop plane aircraft hire available for corporate, private charter and large group transfers. Single and twin turbine engine Turboprops available.
Turbo Prop East, Inc. The Northeast's Largest Independent Turboprop ...
The Northeast's largest, independent Turboprop / Citation maintenance facility, servicing Beechcraft, King Air, Cessna, Citation, Cheyenne and Turbine Commander. Complete one-stop ...
Turbo Prop East, Inc. The Northeast's Largest Independent Turboprop ...
PARTS DEPARTMENT: SPECIAL OFFERS: At Turboprop East, Inc. we have a very comprehensive parts inventory. We specialize in Beechcraft/Raytheon parts ...
turboprop - definition of turboprop by the Free Online Dictionary ...
tur·bo·prop (tûr b-pr p) n. 1. A turbojet engine used to drive an external propeller. 2. An aircraft in which a turboprop is used. Also called propjet.
