横风环境中燃油雾化的微观特性-《内燃机学报》

文章信息/Info

Title:: Experimental Study on the Microscopic Characteristics of Fuel Atomization Under Cross-Flow Condition

Author(s):: Yang Jiya; Wang Chao; Wang Ye; Long Wuqiang; Institute for Internal Combustion Engines, Dalian University of Technology, Dalian 116023, China

Keywords:: fuel atomization; cross-flow condition; microscopic characteristics; droplet diameter distribution; droplet velocity; Sauter mean diameter

摘要:: 燃油雾化的效果将直接影响发动机的燃烧及排放，掌握不同环境条件下的燃油雾化特性对发动机设计有重要的指导意义.采用粒子图像分析(PIA)系统对无横风、横风风速为20m/s和50m/s条件下的燃油雾化微观特性进行了研究，对喷雾不同区域的液滴直径分布、液滴速度以及索特平均直径(SMD)进行了分析.结果表明：在不同的燃油喷雾区域内，液滴直径分布多呈对数正态分布.在横风条件下，液滴直径分布相比于无横风状态更加集中.横风促进了大液滴的破碎，而对于小尺寸液滴而言，横风仅起到输运作用，不能使其破碎成更小的液滴.现存的多种用于计算液滴SMD的经验公式并不能准确地计算喷雾在横风条件下的SMD.笔者通过对不同横风速度下测量得到的燃油喷雾SMD结果进行拟合，得到了横风条件下燃油喷雾SMD与试验条件、燃油物性参数及横风速度的计算关系式.

Abstract:: Abstract: Fuel atomization characteristics under different environmental conditions are important to engine combustion and emissions. Microscopic characteristics of fuel atomization under conditions of no cross-flow and cross-flow velocities of 20 m/s and 50 m/s were studied by using particle image analysis (PIA) system. Droplet diameter distribution,droplet velocity and Sauter mean diameter (SMD) in different spray areas were analyzed. Experimental results show that droplet diameter distribution in different fuel spray areas presents a logarithmic normal distribution. Droplet diameter distribution under cross-flow condition is more concentrated than no cross-flow condition. The cross-flow promotes large droplets breakage. However, it can only have transport function for small droplets, but can not break up them into the smaller droplets.The existing empirical formulas used to calculate SMD does not accurately calculate the SMD value of spray under cross-flow conditions. By fitting the measured SMD results under different cross-flow velocities, the calculation formula between SMD and test condition, fuel physical parameters and cross-flow velocity under cross-flow conditions were obtained.