Turboprop Engines

Turboprop engines are gas turbine engines which is used in aircraft. The gas turbine is designed in such a manner that it drives aircraft propeller using a reduction gear. Turboprops have their origin in the first half of the 20th century.  Gvorgy Jendrassik is considered to be the father of the turboprop, with his first small scale design for the engine appearing in 1937.

The United Kingdom was the site of the production and sale of the earliest mass marketed turbo prop engines. The Rolls Royce Company developed and marketed the RB.50 Trent, considered by many to have set the standard for later developments in turboprop technology. Rolls Royce made use of the knowledge acquired during the development of the Trent and later produced a highly reliable turboprop engine known as the Dart. The design and function of the Dart was such that production of the engine continued for over fifty years.

Turboprop engines are generally used on small subsonic aircraft, but some aircraft outfitted with turboprops have cruising speeds in excess of 500 knots (926 km/h). Large military and civil aircraft, such as the Lockheed L-188 Electra and the Tupolev Tu-95, have also used turboprop power. The Airbus A400M is powered by four Europrop TP400 engines, which are the third most powerful turboprop engines ever produced, after the Kuznetsov NK-12 and Progress D-27.

The turboprop engine is a simple device that includes a turbine, intake, combustor, compressor, and a propelling nozzle. Air flow is processed by the intake and then passed to the compressor. Fuel is added to the compressed air as it passes into the combustor, creating the energy as the mixture passes into the turbine. It is within the turbine that the power used to drive both the propellers and the engine proper is created. A portion of the power keeps the compressor functioning and continuing to pass air into the combustor. The remainder is passed through the propelling nozzle and helps to create the thrust generated by the propeller.

Turboprops are very efficient at flight speeds below 390 knots (725km/h) 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 capability and efficiency at modest flight speeds are required.