Abstract The present contribution falls in the scope of high-frequency combustion instabilities occurring in liquid rocket engines. Under subcritical operating conditions, numerical simulations have to render the effects of acoustic waves on the atomisation of liquid jets since these may impact the stability of the engine. Therefore, the present contribution aims at evaluating the ability of a particular numerical strategy adapted to the simulation of two-phase flows to render these interaction mechanisms. The selected strategy is based on the coupling between a diffuse interface method for the simulation of large liquid structures, and a kinetic-based Eulerian model for the description of droplets. The numerical simulation of an air-assisted liquid jet submitted to a transverse acoustic modulation is performed. The flattening of the liquid core under acoustic constraints is retrieved and induces an intensification of its stripping. In addition, thanks to appropriate coupling source terms, the modification of the spray shape as well as periodic oscillations of droplets are retrieved. The numerical strategy is thus proved to be adapted to deal with atomised liquid jets under transverse acoustic modulation and can be used for future numerical studies of high-frequency combustion instabilities.

中文翻译：

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高频横向声强迫下空气辅助液体射流的大涡模拟

摘要 目前的贡献属于液体火箭发动机高频燃烧不稳定性的范畴。在亚临界运行条件下，数值模拟必须呈现声波对液体射流雾化的影响，因为这些可能会影响发动机的稳定性。因此，目前的贡献旨在评估适用于模拟两相流以呈现这些相互作用机制的特定数值策略的能力。所选策略基于用于模拟大型液体结构的扩散界面方法与用于描述液滴的基于动力学的欧拉模型之间的耦合。执行横向声学调制的空气辅助液体射流的数值模拟。在声学约束下液体核心的扁平化被恢复并引起其剥离的加剧。此外，由于适当的耦合源项，可以恢复喷雾形状的修改以及液滴的周期性振荡。因此，该数值策略被证明适用于在横向声学调制下处理雾化液体射流，并可用于未来高频燃烧不稳定性的数值研究。