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应用相位多普勒测量技术(PDA)对压电晶体控制的外开轴针式喷油器的喷雾场内粒子速度及直径大小进行测量与分析.结果表明,常压条件下,喷雾路径上的粒子速度和粒径都要明显大于喷雾外侧相邻的测量点.环境压力变化影响了气体回流进入喷雾内部的位置,从而使Z=16,mm上的所有测点在两个背压条件下得到了速度方向完全相反的结果.喷油结束后,气体回流不仅使喷雾内部的粒子具有较高的速度,也使喷雾内部的粒子平均粒径明显大于喷雾外侧的粒子平均粒径.采用时间分割法将喷雾划分为4个区域进行分开比较.在喷射过程中,喷雾前端粒子速度较高,粒径较大,但随着喷油结束,喷雾场内的粒子速度接近于零,粒子算数平均直径(AMD)和索特平均直径(SMD)也分别达到了稳定水平.
The velocity and diameter of particles in the atomization field of a piezo-electric controlled open-axial needle injector were measured and analyzed by using phase-doppler measurement (PDA). The results showed that under normal pressure conditions, Particle velocity and particle size should be significantly greater than the adjacent measuring point outside the spray.The ambient pressure changes affect the gas back into the spray inside the position so that all the points on the Z = 16, mm in two back pressure conditions The results of the opposite direction of speed.After the injection, the gas reflux not only make the particles inside the spray have a higher velocity, but also make the average particle size of the particles inside the spray is obviously larger than the average diameter of the particles outside the spray.Using time segmentation The spray was divided into four regions for comparison.During the spraying process, the particle velocity was higher at the front of the spray and the particle size was larger, but with the end of the injection, the particle velocity in the spray field was close to zero and the average particle diameter AMD) and Soter mean diameter (SMD) also reached a stable level.