柴油机直喷压燃工作模式具有热效率高的突出优点，但柴油碳氢燃料的碳链长，难以形成良好的可燃混合气，不是理想的压燃清洁燃料。汽油类燃料有潜力在较宽工况实现高质量的压缩着火燃烧，但目前多采用市场汽油或蒸馏直接得到的石脑油等成品油作为燃料，难以最大限度发挥高效压燃模式的优势。本项目提出一种由C5~C8链烷烃、环烷烃及高碳醇构成的适合压燃的混合燃料。相比于汽油类成品油，该混合燃料具有辛烷值低但敏感度高、挥发性好、粘度高等特点，是直喷压燃发动机可能的理想燃料。基于定容弹、快速压缩机和可视化发动机，采用可视化和模拟方法重点研究这种混合燃料在不同温度和压力条件下喷雾和自燃着火特性，在此基础上建立该混合燃料的自燃化学反应动力机理，提出适合直喷压燃模式的理想燃料的理化特性要求以及燃料组分构成原则和方法。研究工作可以为低碳饱和烃和高碳醇等单组分提供基础的理化特性数据库，具有重要的理论意义和学术价值。

Direct injection compression ignition mode of diesel engines has an outstanding advantage of high thermal efficiency, but the carbon chain length of diesel hydrocarbon fuel is very long with a difficulty to form high quality combustible mixture, which means that diesel fuel is not the clean fuel for compression ignition. Gasoline fuel has potential to achieve high quality compression ignition combustion in a wide range of operation, but at present, most of the gasoline-like fuels directly obtained from market or distillation are used which are difficult to maximize the advantage of compression ignition mode. In this project, a blended fuel of C5~C8 paraffinic hydrocarbons, naphthenic hydrocarbons and high carbon alcohols is proposed for the compression ignition mode. Compared with market gasoline, the blended fuel has the characteristics of low octane number, high sensitivity, good volatility and high viscosity. It might be an ideal blended fuel for direct injection compression ignition engines with a high efficiency and clean combustion. A constant volume bomb, rapid compression machine and transparent visualization engine are utilized to research the blended fuel's spray and ignition characteristics under different temperature and pressure conditions. The chemical reaction mechanism of the blended fuel will be established on the basis of the experimental research results. And the requirements of the physicochemical properties of the ideal fuel and its composition will be proposed for the direct injection compression ignition . The research work can also provide the basic physical and chemical properties database for the single component of low carbon saturated hydrocarbons and high carbon alcohols, which has important theoretical significance and academic value.