Combustion of Jet Fuels and Corresponding Quality Criteria

As their name implies, these products are used essentially for jet aircraft they can also be used in stationary turbines, which are themselves adaptable to a large variety of fuels such as natural gas, LPG, diesel fuel, and heating oil. 

There are several types of jet fuels according to their civilian or military application, their names can vary from one country to another. 

The most widely used product is TRO (TR for turbo-reactor) or JP8 (JP for Jet Propulsion), still designated by the NATO symbols F34 and F35. In the United States, the corresponding fuel is called Jet Al. The military sometimes still uses a more volatile jet fuel called TR4, JP4, Jet B, F45 or F40. The preceding terms correspond to slight variations and it would be superfluous to describe them here. 

There is finally another type of jet fuel somewhat heavier and less volatile than TRO, which allows safe storage on aircraft carriers. This is the TR5 or JP5. Among these products, TRO or Jet Al have the most widespread acceptance because they are used for almost all the world s civil aviation fleet. The information that follows will concern essentially TRO, and very rarely TR4. 

For optimum combustion, the fuel should vaporize rapidly and mix intimately with the air. Even though the design of the injection system and combustion chamber play a very important role, properties such as volatility, surface tension, and fuel viscosity also affect the quality of atomization and penetration of the fuel. These considerations justify setting specifications for the density (between 0.775 and 0.840 kg/1), the distillation curve (greater than 10% distilled at 204°C, end point less than 288°C) and the kinematic viscosity (less than 8 mm /s at -20°C). 

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