Turbomeca Astazou
The Turbomeca Astazou is a shaft turbine from the French manufacturer Turbomeca for driving propeller-driven aircraft with the designation Astazou II. An Astazou IIA version for helicopters was derived from this engine. By 1993, more than 2200 pieces had already been made and it is still in production today (12/2007). The name comes from two mountain peaks in the Pyrenees .
The original version of the engine, Astazou I ran in 1957 and performed at 40,000 min -1 235 kW. It was approved on May 29, 1961 after a 150-hour run. G. Sporer was in charge of the development.
The basic version of the single-shaft engine has a two-stage compressor, the first stage working axially, but the second being radial. The combustion takes place in an annular combustion chamber , from where the hot gas meets a three-stage axial turbine. The maximum permissible speed of the turbine had now been increased to 43,500 min −1 .
In the production engines, the reduction gear is attached in front of the air inlet, which is designed for propeller speeds of 1,800 min −1 , 2,080 min −1 , 2,200 min −1 or 2,400 min −1 . The output speed of the helicopter engines is 6,000 min −1 . The engine regulates itself automatically, so that the pilot only has to specify the speed.
The Astazou II was used on the Potez 840 , the SFERMA Marquis , the Mitsubishi MU-2 and the Pilatus PC-6 A Turbo Porter . For flight tests, individual aircraft Nord 1110 and Dornier Do 27 were also given Astazou engines. With the IIA version, the Aérospatiale 318 C, Alouette II helicopter became a worldwide success.
Starting with the Astazou X version, a second axial compressor stage was installed. This engine was supplied for the Potez 840. The Astazou XIV and XVI were also manufactured by Rolls-Royce Turbomeca International Ltd. sold under the names AZ14 and AZ16 . With the Astazou XVIIIA version, the output could be increased to 783 kW. The Aerospatiale / Eurocopter SA 360 Dauphin is equipped with it.
The XX version has a third axial stage and thus further increased compression. A power of 1075 kW was projected as a turboprop. It was used as XXB in SA 361H Dauphin and made 1043 kW.
Technical execution (Astazou XVI)
The circular air inlet behind the reduction gear has hot air de-icing. The two axial compression stages of the compressor are made of steel using blisk technology. The shaft runs in ball bearings. The flow through the annular combustion chamber is S-shaped. Fuel is supplied in a radial direction through a rotating atomizer disc. The blades of the three-stage turbine, also manufactured as a blisk, are internally cooled by air. The nozzle cannot be moved and has an inner cone. The auxiliary device drives are located on a mounting plate behind the air inlet. There are connections for the starter generator, oil and fuel pump, speed governor and tachometer. There is also the option of attaching an alternator and a hydraulic pump. The engine is suspended at three points, with one bearing journal each on the left and right on the front of the turbine housing and one on the underside in the rear area. The power control takes place by changing the amount of fuel injected with automatic speed control. Brief overload operation is made possible by thermal monitoring. The lubrication is ensured by a pressure oil supply.
Technical specifications
Astazou II IIA III C2/N2 X XIV B/F XIV H/M Leistung kW 390 390 480 465 440 440 Länge mm 1810 1427,50 1433,50 1912 1434 1470/1474 Durchmesser mm 460 Breite mm 516 483 520 500/460 Höhe mm 560 508 623,50 565/570 Gewicht kg 123 142 150,3 128 160 160 Luftmenge kg/s 2,5 Verdichtung 6:1 7,5
