In order to improve the performance of engines fueled with diesel fuel or diesel-like e-fuels so as to realize greener transportation, the V-type and Y-type intersecting hole nozzles, in which each hole is formed by the coalescence of two or three subholes, have been designed. In this article, the multiphase flow inside and outside the nozzle was numerically investigated using a volume-of-fluid large eddy simulation (VOF-LES) method to clarify the effects of the nozzle structure on the cavitating flow and primary atomization characteristics. The calculation was carried out at an injection pressure of 150 MPa and a back pressure of 0.1 MPa. Numerical results showed that unlike the L-shape pressure distribution along a cylindrical hole, for intersecting type hole nozzles, the pressure showed a stepped shape drop along the holes due to the overall convergent hole structure, which restrained the inception of cavitation. Consequently, the global loss of the flow over an intersecting type hole nozzle was lower by 24–37% than those of a cylindrical hole nozzle. Additionally, the jets emerging from the intersecting hole nozzles showed 50% wider spreading angles and 27% smaller droplet sizes than those of the cylindrical hole nozzle. Furthermore, the jets emerging from a Y-type intersecting hole nozzle showed enhanced atomization, which was found to be due to the unstable air suction near the outlets of this type of nozzle hole.

中文翻译：

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使用LES-VOF方法对圆柱形、V型和Y型相交孔喷嘴的喷嘴内空化流动和近场雾化进行数值研究

为了提高以柴油或类柴油燃料为燃料的发动机的性能，以实现更绿色的交通，V型和Y型相交孔喷嘴，其中每个孔由两个或两个相结合形成已经设计了三个子孔。本文采用流体体积大涡模拟（VOF-LES）方法对喷嘴内外多相流进行数值研究，以阐明喷嘴结构对空化流和初级雾化特性的影响。计算在150 MPa的注射压力和0.1 MPa的背压下进行。数值结果表明，与沿圆柱孔的 L 形压力分布不同，对于相交型孔喷嘴，由于整体会聚的孔结构，压力沿孔呈阶梯状下降，从而抑制了空化的产生。因此，相交型孔喷嘴的总流量损失比圆柱形孔喷嘴低 24-37%。此外，与圆柱形孔喷嘴相比，从相交孔喷嘴射出的射流显示出宽 50% 的扩散角和小 27% 的液滴尺寸。此外，Y型相交孔喷嘴射出的射流雾化增强，发现这是由于此类喷嘴孔出口附近的空气吸力不稳定所致。相交型孔式喷嘴的总流量损失比圆柱形孔式喷嘴低 24-37%。此外，与圆柱形孔喷嘴相比，从相交孔喷嘴射出的射流显示出宽 50% 的扩散角和小 27% 的液滴尺寸。此外，Y型相交孔喷嘴射出的射流雾化增强，发现这是由于此类喷嘴孔出口附近的空气吸力不稳定所致。相交型孔式喷嘴的总流量损失比圆柱形孔式喷嘴低 24-37%。此外，与圆柱形孔喷嘴相比，相交孔喷嘴射流的扩散角宽 50%，液滴尺寸小 27%。此外，Y型相贯孔喷口出射的射流雾化增强，发现这是由于此类喷孔出口附近的空气吸力不稳定所致。