ABSTRACT

This research program seeks to understand how the proportions of the fuel ingredients affect the ignition and decomposition characteristics of a novel solid ramjet fuel. The approach involves an ingredient mixture study that varies the proportions of three fuel components over a 10% range: epoxy cured polysulfide polymer, sulfur, and a perfluoropolyether. The primary objective of this work is to demonstrate the manipulation of the lower flammability limit and the thermal desorption species of the various formulations as a direct result of the doping fractions of sulfur and perfluoropolyether. Laboratory experiments include closed cup flash point testing and pyrolysis gas chromatography mass spectroscopy. The results show that, for the conditions investigated, both sulfur and perfluoropolyether act to decrease the lower flammability limit when added to polysulfide fuel. Low ignition temperature species including hydrogen sulfide are desorbed from sulfur-doped formulations. The mole fractions of diluent species decrease with the addition of either sulfur or perfluoropolyether. These experiments isolate the fundamental fuel properties by decoupling fuel behavior from combustor operating parameters such as geometry, chamber pressure, air temperature, and flux. Understanding relationships between the controlling mechanisms of solid fuel ramjet performance and fundamental fuel properties can aid in design prior to static firings.

摘要

该研究计划旨在了解燃料成分的比例如何影响新型固体冲压喷气发动机燃料的点火和分解特性。该方法涉及成分混合物研究，该研究在 10% 范围内改变三种燃料成分的比例：环氧固化多硫化物聚合物、硫和全氟聚醚。这项工作的主要目的是证明对各种配方的可燃性下限和热解吸物质的操纵是硫和全氟聚醚的掺杂分数的直接结果。实验室实验包括闭杯闪点测试和裂解气相色谱质谱。结果表明，对于所研究的条件，当添加到多硫化物燃料中时，硫和全氟聚醚都会降低可燃性下限。包括硫化氢在内的低点火温度物质从硫掺杂配方中解吸出来。稀释剂物质的摩尔分数随着硫或全氟聚醚的添加而降低。这些实验通过将燃料行为与燃烧器运行参数（例如几何形状、燃烧室压力、空气温度和通量）分离来隔离基本燃料特性。了解固体燃料冲压发动机性能的控制机制与基本燃料特性之间的关系有助于在静态点火之前进行设计。稀释剂物质的摩尔分数随着硫或全氟聚醚的添加而降低。这些实验通过将燃料行为与燃烧器运行参数（例如几何形状、燃烧室压力、空气温度和通量）分离来隔离基本燃料特性。了解固体燃料冲压发动机性能的控制机制与基本燃料特性之间的关系有助于在静态点火之前进行设计。稀释剂物质的摩尔分数随着硫或全氟聚醚的添加而降低。这些实验通过将燃料行为与燃烧器运行参数（例如几何形状、燃烧室压力、空气温度和通量）分离来隔离基本燃料特性。了解固体燃料冲压发动机性能的控制机制与基本燃料特性之间的关系有助于在静态点火之前进行设计。