CAREER: Disruption and Vaporization of Superheated Droplets in Compressible Flow

Hermanson, James C.高速气流中液滴的破碎和汽化发生在两相流、喷雾干燥、火箭喷嘴流动、液体燃料喷射和汽轮机叶片侵蚀中。如果能够实现高水平的分散和快速混合，在许多应用中可以实现相当大的实际优势。一种技术是快速汽化，它涉及过热液体的剧烈破坏和汽化。现有的文献大多集中在不可压缩流动上，不适用于超音速燃烧室中的可压缩流动。过热液滴破裂、汽化和燃料/空气混合的物理学还没有很好地建立起来。提出的研究计划是对超音速流动中过热液体燃料破坏和汽化的基本物理进行全面的实验研究，其中液滴的整个体积被带到高水平的过热以促进闪蒸。这项工作将是实现对可压缩流动中过热液体燃料喷雾行为的基本理解的第一步，特别关注影响液滴历史的不同不稳定机制。液滴将被注入到超音速流中，它们的加速和随后的蒸发将主要通过平面激光诱导荧光和激光火花纹影/阴影图来检测。

Abstract - CTS-9733830 Hermanson, James C. The breakup and vaporization of liquid droplets in a high-speed gas stream occurs in two-phase flows, spray drying, rocket nozzle flow, liquid fuel injection, and steam turbine blade erosion. Considerable practical advantages in many applications could be realized if high levels of dispersion and rapid mixing were achieved. One technique is that of flash vaporization which involves violent disruption and vaporization of superheated liquids. Most of the extant literature is focussed on incompressible flows and is not applicable to compressible flows, which are found in supersonic combustors. The physics of superheated liquid droplet disruption, vaporization, and fuel/air mixing are not well established. The proposed research program is a comprehensive, experimental investigation of the fundamental physics of superheated liquid fuel disruption and vaporization in supersonic flow, where the entire volume of the droplet is brought to a high level of superheat to promote flash vaporization. This work will be a first step towards achieving a fundamental understanding of the behavior of superheated liquid fuel sprays in compressible flow, with particular attention paid t the different instability mechanism which affect the droplet history. Droplets will be injected into a supersonic stream and their acceleration and subsequent vaporization will be examined primarily by planar laser-induced fluorescence and laser-spark schlieren/shadowgraphs.