柴油机燃油喷射雾化的PIV测量试验研究

Experimental Study on Fuel Injection Spray of Diesel Engine by PIV Measurement

介绍了先进的粒子图像测速技术(PIV)应用于燃油喷雾过程的试验研究结果,燃油通过多种孔径的单孔和多孔喷油嘴喷入一个定容压力室内,采用高分辨率的CCD摄像机记录整个喷射过程,可以观察到喷雾场内部结构.结果分析显示,高速射流表面存在不稳定扰动波,在气动力作用下,液滴发生分裂破碎,呈现枝状分离表面.瞬态速度矢量图显示,气液界面处存在大尺度的卷吸涡流运动,有助于油气扩散混合.

Some research results on fuel injection spray were introduced by using advanced particle image velocity (PIV) technique. The fuel was injected into a non-combusting environment high-pressure vessel passing through single hole or multihole nozzle. The spray progress was recorded by high-definition CCD camera, which let us observe the detail structures of spray. The experimental results show that many unsteady distribution waves exist on the surface of high-speed jet. The spray will breakup into small droplets with branch-like structures under the action of aerodynamic shear forces. The large-scale vorticity movement on interface between liquid and gas are observed on instantaneous droplet velocity vectorgraph. These movements are a help to improving the mixture between droplets and surrounding gas.