高压环境下燃料液滴蒸发与燃烧特性

Evaporation and Combustion Characteristics of Fuel Droplet Under High Ambient Pressure Environments

介绍了燃料液滴实验技术现状、高压环境下液滴蒸发与燃烧试验设备现状以及高压环境下液滴蒸发与燃烧特性。单滴燃料的研究是掌握喷雾燃烧机理和计算模型的基础,而高压环境以及超临界环境中燃料液滴蒸发与燃烧特性更是燃烧学领域长期以来备受关注的重要研究内容。液体燃料以亚临界初始温度喷射雾化进入燃烧室,雾化形成的燃料液滴在高于其临界压力和临界温度的环境下经历蒸发、与空气混合、着火和燃烧过程,在此持续期内,液滴从亚临界温度迅速加热升温并有可能发生由亚临界状态至超临界状态的迁移,由于超临界状态下流体的密度、粘度、表面张力、蒸发潜热、传热系数以及溶解度等所有流体的物性会发生急剧变化,使得高压超临界环境下燃料液滴的蒸发与燃烧现象相对于低压环境会发生明显的变化。

The current state of fuel droplet experimental techniques,the status of droplet evaporation and combustion test equipment under high ambient pressure environments,as well as the characteristics of droplet evaporation and combustion in high ambient pressure environments are introduced.Research on single fuel droplet is fundamental to understanding the mechanisms of spray combustion and computational models,while the evaporation and combustion characteristics of fuel droplets in high-pressure and supercritical environments have long been a significant focus in the field of combustion science.Liquid fuels are injected and atomized into the combustion chamber at subcritical initial temperatures,and the resulting fuel droplets undergo evaporation,mixing with air,ignition,and combustion processes in an environment above their critical pressure and temperature.During this period,the droplets are rapidly heated from subcritical temperature and may undergo a transition from subcritical to supercritical states.Due to the dramatic changes in fluid properties such as density,viscosity,surface tension,latent heat of evaporation,heat transfer coefficient,and solubility in the supercritical state,the evaporation and combustion phenomena of fuel droplets in high-pressure supercritical environments exhibit noticeable differences compared to low-pressure environments.