This paper focuses on developing and applying a drop-wall interaction model for high ambient pressure conditions. In an internal combustion engine, the high-speed fuel spray can impinge on the piston surface, particularly for early injection and cold start. Drop-wall interactions can cause a wall film that adversely affects combustion and emissions performance. The present drop-wall model is derived from the numerical results obtained using the smoothed particle hydrodynamics (SPH) method, a high-fidelity method for simulating fluid flows. The current model is comprehensive as it considers the effects of wall temperature and ambient pressure. The model predicts four different impact outcomes (i.e., deposition, rebound, contact splash, and film splash) for dry wall impact, and two impact outcomes (i.e., deposition and splash) for wet wall impact. The model provides the mass distribution of the resulting wall film and secondary droplets, the latter with proper velocities. The present model was used to simulate diesel spray-wall interactions in a high-pressure constant-volume chamber. Various operating conditions were simulated, including different injection pressures and ambient densities. Predicted spray patterns and droplet distributions were compared with the experimental data. Good levels of agreement were obtained. With its ability to consider the effects of wall temperature and ambient pressure, the present model has the potential to predict drop-wall interactions accurately at extreme conditions.

中文翻译：

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高压环境下落墙相互作用模型的开发与应用

本文的重点是开发和应用高环境压力条件下的落壁相互作用模型。在内燃机中，高速燃油喷射会撞击活塞表面，特别是对于早期喷射和冷启动。落壁相互作用会产生对燃烧和排放性能产生不利影响的壁膜。目前的落壁模型源自使用平滑粒子流体动力学 (SPH) 方法获得的数值结果，这是一种模拟流体流动的高保真方法。当前模型是全面的，因为它考虑了壁温和环境压力的影响。该模型预测了干壁冲击的四种不同的冲击结果（即沉积、回弹、接触飞溅和薄膜飞溅），以及湿壁冲击的两种冲击结果（即沉积和飞溅）。该模型提供了所得壁膜和二次液滴的质量分布，后者具有适当的速度。本模型用于模拟高压定容室中的柴油喷射壁相互作用。模拟了各种操作条件，包括不同的注射压力和环境密度。预测的喷雾模式和液滴分布与实验数据进行了比较。获得了良好的协议水平。由于能够考虑壁温和环境压力的影响，本模型有可能在极端条件下准确预测落壁相互作用。本模型用于模拟高压定容室中的柴油喷射壁相互作用。模拟了各种操作条件，包括不同的注射压力和环境密度。预测的喷雾模式和液滴分布与实验数据进行了比较。获得了良好的协议水平。由于能够考虑壁温和环境压力的影响，本模型有可能在极端条件下准确预测落壁相互作用。本模型用于模拟高压定容室中的柴油喷射壁相互作用。模拟了各种操作条件，包括不同的注射压力和环境密度。预测的喷雾模式和液滴分布与实验数据进行了比较。获得了良好的协议水平。由于能够考虑壁温和环境压力的影响，本模型有可能在极端条件下准确预测落壁相互作用。