柴油机碰撞分流喷雾方案对比试验研究

Comparative experimental study on impinging flow guide scheme of diesel engine spray

在定容弹试验台上,对2种结构的碰撞分流燃烧室方案的燃油雾化过程进行了对比研究,分析了碰撞分流方案及背压对燃油雾化效果的影响。结果表明:碰撞导向面方案对燃油的剥离作用更为明显,其燃油空间分布范围更大,油气混合更为均匀;油束与碰撞凸缘方案的外凸结构碰撞后迅速向两侧运动,碰撞面对油束来流方向速度的限制作用不大,导致碰撞后燃油大部分堆积在燃烧室壁面位置附近,空间分布范围较小;随着背压升高,碰撞油束的壁面剥离现象及油束锋面的扩散现象均更为明显。

Comparative experimental study of spray characteristics were carried out on a constant volume bomb test bench using spray visualization method. Two schemes of impinging flow guide combustion chamber were employed, and the effect of impinging scheme and ambient pressure on atomization characteristics were analyzed. The results show that the impinging guide surface scheme leads to more obvious stripping effect, much larger distribution area and more homogenous mixture. After impinging with flanged structure, the spray rapidly moves to side and impinging surface has little effect on spray velocity on approaching direction, which results in fuel accumulation around wall location of combustor and smaller distribution range of fuel. Both stripping effect of impinging spray and diffusing effect of beam front become more obvious with the increase in ambient pressure.