Fuel aviation

According to the type of propulsion (turbines, piston engines), the aircraft burn various types of fuels.

Fuels based on the kerosene

The engines of aviation to turbine (Turbojet S, Turbopropeller S) use fuels containing Kérosène. In civil aviation, the fuel of this most widespread type is the Jet A-1 , defined by the international standard AFQRJOS ( Aviation Fuel Quality Requirements for Jointly Operated Systems ), which freezes to the maximum with -47 °C. With the the United States, there exists also containing hydrocarbon a Jet has , whose manufacture is a little less expensive but which freezes with an higher temperature (- 40 °C). The American military fuel standard JP-8 is close to the Jet A-1, except for some additives. For a use in cold environment, in particular in Canadian north, there exists also a specification Jet B ; this fuel includes to kerosene in addition a fraction of gasoline (cut naphtha), which enables him to remain liquid at lower temperatures. However, the use of this fuel is falling in disuse. In addition to the higher price of such a fuel with broad cut of distillation, one can also quote a higher risk of ignition because of the more important volatility of the gasoline. The Russians have them also a specific standard for the use in the cold zones TS 1 .

Because of particular constraints of use, there was a certain variety of fuel standards of military aviation. Let us quote an exceptional fuel, the JP-7, developed for the reconnaissance aircraft American SR-71 ; this very expensive special mixture, almost without impurities, had in particular a temperature of very high ignition and a good stability in temperature. The new generations of engines asking as for them for a fuel resisting the high temperatures better, one saw appearing these last years a fuel JP 8 +100 but whose utility remains discussed. The specific use of the embarked aircraft requires as for it a fuel having a higher flash point, called JP 4 . One of great specificities of jet fuels of military use is the quasi systematic use of fuels containing an additive anti-ice (various names: FSII , AL-41 or S-1745 ). Indeed the military aircraft not being always equipped with heaters on the level of the filters, there exists a risk of filling related to the appearance of interstitial water following the fall in temperature in high-altitude. The role of this additive is to prevent the agglomeration of the microphone-ice floes thus formed, maintaining in on this side performances of the filters of edge and thus avoiding any risk of extinction of the engine.

Gasoline aviation and diesel

The piston engine of planes function traditionally with gasoline aviation ( avgas 100LL and 110LL also in the past 115), a fuel similar to the automobile gasoline but with more extremely Number octane, containing tetraethyl lead, of a formulation far from aggressive (not of solvent alcohols nor) and drained perfectly (to avoid icing). Because of the high cost of the gasoline aviation, certain not very powerful engines of small apparatuses can, with restrictions of use, to function with automobile gasoline ( mogas ). In addition, of the manufacturers currently develop diesel engine accepting the kerozene Jet-HAVe, near to the gas oil but less fatty and deprived of paraffins, particularly economic and enduring, but very expensive with the purchase, a little noisier especially for the diesel 2 times (ex: Wilksch) and heavier with power equalizes for 4 times (SMA Morane-Renault or Thielert).

The diesel engines in aviation are not an innovation: Clerget built radial engines in the Thirties as Junkers-Jumo which equipped with the piston engines opposed in particular the bomber S German and Dirigeable S.

The oil companies proposing of the gasoline aviation are traditionally the same ones as for the car: Total Air and BP Air for example.

References

Rafter, Aviation fuels technical review , 2000

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