chapter  5
20 Pages

COMBUSTION CHARACTERISTICS OF HIGH-ENERGY-DENSITY FUELS AND SOLID GAS INTERFACE ANALYSES

In order to improve the performance of air-breathing propulsion systems at-

tention has been focused on means of increasing the energy-density of existing

fuels by including energetic metallic/nonmetallic additives, such as aluminum,

boron, or other synthetic formulations. New hydrocarbon fuels, with high-

energy-density content, have been synthesized and their combustion character-

istics assessed under a variety of thermodynamic air ow conditions. These fuels

have the potential to contribute to high-thrust, high-temperature, and reduced-

size combustor technology. Marchand [1], Segal and Shyy [2], and Yang and

Zarko [3] have reviewed various aspects of these research activities. Since the

newly synthesized hydrocarbon fuels owe their high-energy content either to

strained molecular bonds or to densely packed molecular structures, many of

these formulations are solids at normal conditions. It had been found that among

these materials certain solid formulations that dissolve in stable solutions exist

in liquid fuel systems in substantial concentrations [4]. Due to the compact vol-

umes and large heat release rates exhibited, these materials can possibly be used

as additives in existing liquid fuel systems. While their stability is an asset from

the point of view of handling logistics, these fuels exhibited a high-activation

energy for ignition and, due to the large carbon-to-hydrogen ratio, these fuels

have a propensity to soot.