运用数字粒子图像测速技术测量柴油瞬态喷雾

Experimental Study on Spray Characteristic of Diesel Fuel by Digital Particle Image Velocimetry

分析了数字粒子图像测速(DPIV)技术的基本原理,建立了一套柴油喷雾激光测量试验系统,运用DPIV技术对柴油喷雾结构进行了可视化测量,并测量了柴油的瞬态喷雾特性.研究结果表明,燃油喷雾速度随着喷雾时间的推延逐步降低,在喷雾后期喷雾速度降低尤为迅速;柴油瞬态喷雾具有典型的“树枝”状拟序结构;油粒速度沿轴线方向增加,外围油粒速度远小于核心油粒;喷雾与周边空气发生了“卷吸”作用,在喷雾内部形成了复杂的涡旋运动,涡度沿喷雾轴线方向增大.

This paper introduced the principle of digital particle image velocimetry （DPIV） and developed a device for the measurement of diesel fuel spray by laser technique,which is used for the DPIV measurement of the structure of diesel fuel spray.The velocity of fuel spray decreases with the delay of the injection time, and reduces rapidly at the evening of the injection.The unique branch-like structures of fuel spray are clearly observed. The droplet velocity increases along the axial direction, and the velocity of amblent droplet is less than that of core region.The spray droplets interact with the surrounding gas. The active vortical motions appear within the spray, and increase along the axial direction.