A Basic Experimental Study of Gasoline Direct Injection at Significantly High Injection Pressures
A Basic Experimental Study of Gasoline Direct Injection at Significantly High Injection Pressures
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DOI：
10.4271/2005-01-0098
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发表时间：
2005-04
期刊：
影响因子：
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通讯作者：
A. Nauwerck;J. Pfeil;A. Velji;U. Spicher;B. Richter
中科院分区：
文献类型：
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作者：
A. Nauwerck;J. Pfeil;A. Velji;U. Spicher;B. Richter
在采用分层燃烧策略的汽油直喷发动机中，只有很短的时间可用于混合气制备。因此，进行调查，以评估高达50 MPa的高注射压力的影响，以优化混合物的制备。在压力容器中对两种多孔喷油器在不同压力和温度条件下的性能进行了分析。应用激光片光可视化技术，以确定喷雾特性，如形状，角度，穿透深度和喷雾宽度。为了确定喷雾周围空气的速度，使用PIV（粒子图像测速）测量技术。用相位多普勒风速仪（PDA）在喷雾中心和喷雾边缘的不同位置测量液滴尺寸和速度。喷雾可视化实验表明，在较高的温度下，蒸发对喷雾传播的影响。随着腔室压力的增加，观察到射流变宽，而其长度几乎保持不变。PIV测量表明，在喷雾前端和一个独特的空气夹带到喷雾，这取决于喷射压力和腔室压力的环形流。用PDA对液滴速度和直径的分析表明，在较高的喷射压力下，非常小的液滴的速度很高。然而，液滴速度并不像燃料压力那样在相同的维度上增加。
In gasoline direct injection engines with stratified-combustion strategies only a short time is available for mixture preparation. Therefore, investigations are carried out to evaluate the influence of high injection pressure up to 50 MPa in order to optimize the mixture preparation. Two types of multi-hole injectors are analyzed in a pressure vessel under various pressure and temperature conditions. Laser light sheet visualization technique is applied in order to determine spray characteristics like shape, angle, penetration depth and spray width. To determine the velocity of the air surrounding the spray, a PIV (Particle Image Velocimetry) measurement technique is used. Droplet sizes and velocities are measured with a Phase Doppler Anemometer (PDA) in different positions in the spray center and at the spray edge. Spray visualization experiments show the influence of evaporation on spray propagation at higher temperatures. With increasing chamber pressure, a widening of the jet is observed, while its length remains nearly constant. PIV-measurements show a torus-like flow at the spray front and a distinctive air entrainment into the spray, which depends on injection pressure and chamber pressure. Analyses of droplet velocity and diameter with PDA reveal high velocities of very small droplets at higher injection pressures. However, droplet velocity does not increase in the same dimension as does the fuel pressure.