Supersonic aircraft fuel

Super slurper Supersonic aircraft fuel Supertarget Super three SUPERTRAP Supplies... 

Hill, E. C. and Thomas, A. R., 1975. Microbiological aspects of supersonic aircraft fuel. In Proceedings of the 3rd International Biodegradation Symposium, pp. 157-174. 

Because of tank heating, fuel volatiUty is also more critical in supersonic aircraft. For example, the Concorde tank is pressurized to prevent vapor losses which could be significant at high altitude where fuel vapor pressure may equal atmospheric pressure. The tank can reach 6.9 kPa (1 psi) at the end of a flight. The need to deoxygenate fuel for thermal stabiUty in the HSCT will doubdess require a similar pressurized system. 

Briefly, JP-4 is a wide-cut fuel developed for broad availability in times of need. JP-6 is a higher cut than JP-4 and is characterized by fewer impurities. JP-5 is specially blended kerosene, and JP-7 is a high-flash-point special kerosene used in advanced supersonic aircraft. JP-8 is a kerosene fraction that is modeled on jet A-1 fuel (used in civilian aircraft). For this profile, JP-4 will be used as the prototype jet fuel, due to its broad availability and extensive use. 

TABLE 4. Types of experiments used in the study. For supersonic aircraft, Z (km) indicates the cruising altitude with emission index (EI=g of NO, emitted/kg of burnt fuel). 

Electro-insulation materials. The retention of dielectric properties in a high-temperature environment, coupled with good corrosion resistance in contact with certain reactive chemicals, suggests excellent possibilities of polybenzimidazole use in electrical insulation and other dielectric applications at high operating temperatures and/or in aggressive chemical environments. Typical applications, hence, can be foimd in special cable and wire insulation, in the manufacture of circuit boards and radomes for supersonic aircraft, as battery and electrolytic cell separators, and as fuel cell frame structural materials. Some recent publications in the patent and technical report literature may serve to illustrate such applications. 

Fuel passing through certain hot zones of an aircraft can attain high temperatures moreover it is used to cool lubricants, hydraulic fluids, or air conditioning. It is therefore necessary to control the thermal stability of jet fuels, more particularly during supersonic flight where friction heat increases temperatures in the fuel tanks. 

The first commercial supersonic transport, the Concorde, operates on Jet A1 kerosene but produces unacceptable noise and exhaust emissions. Moreover, it is limited in capacity to 100 passengers and to about 3000 miles in range. At supersonic speed of Mach 2, the surfaces of the aircraft are heated by ram air. These surfaces can raise the temperature of fuel held in the tanks to 80 °C. Since fuel is the coolant for airframe and engine subsystems, fuel to the engine can reach 150°C (26). An HSCT operated at Mach 3 would place much greater thermal stress on fuel. To minimize the formation of thermal oxidation deposits, it is likely that fuel deflvered to the HSCT would have to be deoxygenated. 

The need for thermal stability of jet fuels is based on the following facts. In supersonic flight, the aircraft is subjected to high temperatures. This heat must be removed. Most convenient solution, in many types of jet aircraft, would be to use the fuel as a heat sink for cooling vital aircraft components, such as engine oil... 

Perhaps the biggest thrust for the development of high performance polymers over the next 10 years will be in the aerospace industry where materials will be required for a fleet of high speed civil transports (supersonic transports). At a speed of Mach 2.4, an aircraft surface temperature of about 150 to 180°C will be generated. The life requirement of materials at these temperatures will be about 60000 hours. Many different types of materials such as adhesives, composite matrices, fuel tank sealants, finishes and windows will be needed. These materials must exhibit a favorable combination of processability, performance and price. The potential market for these materials total several billions of US dollars. 

In aircraft jet fuels, for example, especially those for aircraft of the supersonic type, the chief problem so far encountered has been thermal stability prior to combustion. The fuel must be used as a cooling agent, and the resultant exposure to heat accelerates the formation of gum and sediment. These cause plugging of filters and fuel nozzles, and lacquering of heat-exchanger surfaces. Research to date has indicated that some additives are effective in improving jet-fuel stability (52), especially if the fuel has first been rigorously refined, but these additives are not combustion improvers in the sense discussed in this paper. 

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