Abstract A synergistic effect on low-temperature autoignition reactivity of blending two high-octane compounds, i.e. cyclopentane and diisobutylene, was observed in engine experiments and ignition delay time measurements at 700–880 K and up to 25 bar with a rapid compression machine. Results show that the low-temperature ignition delay and RON of a cyclopentane-diisobutylene blend are inferior to those of its isolated blendstocks, therefore exhibiting an increased reactivity towards ignition at the tested conditions. Sampling and speciation of the reacting mixture during the ignition delay of pure compounds and the most reactive blend was conducted to support discussions focused on the kinetic perspective to this phenomena, which suggest that the separate chain initiation pathways of these potential high-octane blendstocks can interact with each other to help the radical pool growth at the beginning stage of the autoignition chemistry, and finally accelerate the propagation and branching pathways to promote the global reactivity. This result in significant two-stage ignition behavior for the blend, which is not observed at this temperature for both isolated blendstocks. These findings are especially meaningful for designing and blending suitable high-octane fuels for advanced combustion mode engines.

中文翻译：

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高辛烷值燃料：二异丁烯和环戊烷的协同低温反应性、拮抗性 RON 混合的动力学研究

摘要 在发动机实验和点火延迟时间测量中，使用快速压缩机在 700-880 K 和高达 25 bar 下观察到混合两种高辛烷值化合物（即环戊烷和二异丁烯）对低温自燃反应性的协同作用。结果表明，环戊烷-二异丁烯共混物的低温点火延迟和 RON 不如其分离的共混料，因此在测试条件下表现出更高的点火反应性。在纯化合物和最具反应性的混合物点火延迟期间对反应混合物进行采样和形态分析，以支持针对这种现象的动力学观点的讨论，这表明这些潜在的高辛烷值混合原料的单独链引发途径可以相互作用，以帮助自燃化学开始阶段的自由基池增长，并最终加速传播和支化途径以促进整体反应性。这导致混合物具有显着的两阶段点火行为，在此温度下两种分离的混合物都未观察到这种情况。这些发现对于为先进燃烧模式发动机设计和混合合适的高辛烷值燃料特别有意义。在此温度下，两种分离的混合原料都没有观察到这种情况。这些发现对于为先进燃烧模式发动机设计和混合合适的高辛烷值燃料特别有意义。这在此温度下对于两种分离的混合原料都没有观察到。这些发现对于为先进燃烧模式发动机设计和混合合适的高辛烷值燃料特别有意义。