中文摘要：

在环境温度为293K、压力为0．1MPa条件下，采用数字粒子图像速度场仪研究了单孔直喷式柴油喷嘴形成的二甲醚（DME）闪急沸腾喷雾的结构及发展过程．为得到喷雾图像，采用Nd：YAG激光光片将喷雾照亮．喷雾图像采用高分辨率的CCD照相机来记录，通过图像采集卡传输到计算机硬盘进行保存．结果表明，DME闪急沸腾喷雾由初始核区、闪急沸腾主体区和涡环形成区3部分组成；根据涡环结构的形成与发展变化，可将DME闪急沸腾喷雾扩展过程分为涡环结构形成、涡环结构发展与变形、涡环结构破碎和闪急沸腾喷雾充分发展4个阶段．

英文摘要：

At the ambient temperature Ta = 293 K and the ambient pressure pa = 0.1 MPa, the structure and development process of DME flash boiling spray, formed by a single-hole DI diesel injector, were investigated by digital particle image velocimetry （DPW）. The sprays were ilhaninated by a Nd： YAG laser light sheet for getting spray images. The spray images were recorded by using a high-resolution CCD camera and stored on the hard driver of computer through an image acquisition board. The results show that the DME flash boiling spray is composed of three parts, such as spray initial core region, main body region of flash boiling spray and vortex ring formation region. Based on the vortex ring structure formation and variation, the development process of DME flash boiling spray can be divided into four stages： vortex ring structure forming stage, vortex ring structure developing and distoaing stage, vortex ring structure break-up stage, and fully developed stage of flash boiling spray.