In order to sustain applications dealing with various liquid fuels in internal combustion engine (ICE), it is essential to make available prediction methodologies that allow an early evaluation of the potential usefulness of such fuels in terms of favourable mixture preparation process already in realistic configurations. Since the air-mixture formation and subsequent processes are predominantly governed by the fuel injection, a DNS based numerical investigation coupled with VOF as an interface tracking method is carried out in this paper to gain better insight on the fuel injection from an industrial injector "Spray G" configuration. Chosen from Engine Combustion Network (ECN), this is a gasoline direct injector (GDI) featuring 8-holes orifices and operating with high injection pressure (200 bar). Under consideration of the required computational cost associated with DNS, only the 1/8 of the nozzle geometry including one orifice is used. The numerical simulation is accomplished for the quasi-steady injection condition with nozzle needle fully opened. The obtained results are first validated with available experimental data for nozzle mass flow rate and spray spread angle showing a good agreement. Then, a detailed numerical analysis is provided for the in/near nozzle flow evolution especially for flow turbulence, primary and secondary atomization. Furthermore, droplet statistics in terms of droplet shape, and droplet size-velocity distribution together with a breakup regime map are reported. Finally, a 2-D data curation technique is proposed to extract the droplet statistics along selected planes and evaluated by direct comparison with three-dimensional droplet data, which may allow handling of the DNS data in more feasible and economical way especially for time series data with higher frequency. The comprehensive DNS data generated by this DNS-VOF approach enable not only to carry out detailed numerical analysis of in- and near-nozzle physical phenomena for which experimental data are still scarce, but also to provide a hint of more reliable injector boundary conditions useful for lower order spray injection method based on Lagrangian particle tracking.

为了维持内燃机（ICE）中各种液体燃料的应用，有必要提供可用的预测方法，以便尽早评估此类燃料在实际配置中的有利混合物制备过程方面的潜在用途。由于空气混合物的形成和后续过程主要由燃油喷射控制，因此本文进行了基于 DNS 的数值研究，并结合 VOF 作为界面跟踪方法，以更好地了解工业喷射器“喷雾”的燃油喷射。 G”配置。这是从发动机燃烧网络 (ECN) 中选择的汽油直喷器 (GDI)，具有 8 孔孔并在高喷射压力 (200 bar) 下运行。考虑到与 DNS 相关的所需计算成本，仅使用包括一个孔口的喷嘴几何形状的 1/8。对喷嘴针全开的准稳态喷射工况进行了数值模拟。所获得的结果首先用喷嘴质量流量和喷雾扩散角的可用实验数据进行了验证，显示出良好的一致性。然后，对喷嘴内/附近的流动演变进行了详细的数值分析，特别是流动湍流、初级和次级雾化。此外，还报告了液滴形状、液滴尺寸-速度分布以及破碎状态图方面的液滴统计数据。 最后，提出了一种二维数据管理技术来提取沿选定平面的液滴统计数据，并通过与三维液滴数据的直接比较进行评估，这可以允许以更可行和经济的方式处理 DNS 数据，特别是对于时间序列数据以更高的频率。这种 DNS-VOF 方法生成的全面 DNS 数据不仅能够对实验数据仍然匮乏的喷嘴内和近喷嘴物理现象进行详细的数值分析，而且还可以提供更可靠的喷油器边界条件的提示。基于拉格朗日粒子跟踪的低阶喷雾喷射方法