Morphology of Deposits in Aircraft and Engine Fuel Systems 700258
Deposits produced in a wide variety of fuel system simulators and fuel test rigs were found to be remarkably consistent in their microstructure. The deposits were built from soft particles measuring about 1000 Angstrom units in diameter. These microspheres form random three-dimensional structures on the deposit face, which become more closely packed in the deposit substrate, and undergo fusion on heated surfaces.
It is postulated that thermal stressing generates micelles in the fuel, and that deposits are formed by the collection of these particles from the fuel. Therefore, it is proposed that a standard method of test for fuel quality control should evaluate the deposit potential of fuels, free from the collection efficiency of physical systems. The 5 ml Bomb Procedure, which is based on the decrease in light transmittance through the fuel when thermally stressed, appears to be suitable for this purpose.