汽油缸内直喷多孔喷油器喷雾碰壁特性试验

Experiment on impingement spray characteristics of multi-hole injector in gasoline direct injection engine

为了研究缸内直喷汽油机多孔喷油器的碰壁喷雾特性,建立了定容碰壁喷雾试验装置,对不同喷油压力和不同环境压力条件下的碰壁喷雾过程进行了拍摄,同时考虑壁面与喷嘴的距离和壁面倾角对碰壁喷雾特性的影响.结果表明:增加喷油压力可以使碰壁喷雾高度和半径增大,但是碰壁喷雾高度的增加率随喷油压力的增加而减小;随着环境背压的增大,碰壁喷雾高度和半径均减小,进一步增大环境背压,则碰壁喷雾高度增大;加大撞击壁面与喷嘴的距离和壁面倾角,碰壁喷雾高度和喷雾半径均增大,当壁面倾角进一步增大,碰壁液滴总动能减少,而且受到喷雾油束边缘的运动阻力,碰壁喷雾半径减小.

To investigate the impingement spray characteristics of multi-hole injector in gasoline direct injection engine, the capacity impingement spray experiment device was established. The impingement spray was carried out under the conditions of different ambient pressure and injection pressure. The in- fluences of wall inclination and wall distance from injector orifice were considered. The results show that the spray height and the spray radius are increased by the increase of injection pressure. The increasing rate of spray height is decreased with the increase of injection pressure. With the increasing of ambient pressure, the spray height and the spray radius are decreased. However, if ambient pressure rises fur- ther, the spray height increases too. The larger the distance from wall to injector orifice and wall inclination is, the greater the spray height and the spray radius will be obtained. The wall inlcination is further increased, the total momentum of impingement droplets is decreased with decreased spray radius due to the spray resistance of outgoing droplet edges.