Pressure Effects on Flowing Mildly-Cracked n-Decane

It is anticipated that traditional methods of cooling that employ the sensible heat transfer provided by fuels will not be sufficient to meet the cooling requirements of future high-performance aircraft. One potential solution is the use of endothermic fuels, which absorb heat through chemical reactions. However, few studies have analyzed the effects of pressure on a chemically reacting, flowing fuel. An experiment is described that studies the effects of pressure on flowing, mildly cracked, supercritical n-decane. The experimental results are studied with the aid of a unique two-dimensional computational fluid dynamics model that simulates the formation of cracked products from experimentally derived proportional distributions. This model is used to study the effect of pressure on the flow properties of the fuel. The experiments indicate that increasing pressure enhances bimolecular pyrolysis reactions, relative to unimolecular reactions. Increasing pressure also increases the overall conversion rate of supercritical n-decane flowing through a reactor. This is primarily because pressure increases the density, which increases the residence time of n-decane flowing through the reactor.