PRIME: Unresolved fluid mechanics at liquid/gas interfaces for PRIMary brEakup of atomizing sprays

有效的喷雾雾化在社会中发挥着关键作用，从有效的医疗到更清洁的推进系统。初级破碎-将液体流破碎成大的（初级）液滴的过程-是雾化的第一步，但也是雾化喷雾最不了解的。这个长期存在的问题是由于缺乏实验工具，可以测量的基本流体动力学，管理的主要破碎过程中的液-气界面（LGI）在喷雾的核心。PRIME是为解决这个问题而设计的。我们开发了一套独特的先进诊断工具，提供测量液体射流和初始液滴LGIs处流体速度和加速度的独家能力。这些工具是脉冲群弹道成像与基于小波的光流（wOF）的独特组合。在PRIME中，我们建立了我们的概念验证工具，并利用双光子激光诱导荧光为原始应用开发了wOF，以提供突破性的测量，帮助解决未解决的初级分裂问题。PRIME将开发两个喷雾设施，这为我们提供了一个独特的平台，用于诊断从基本到技术相关的复杂喷雾的一系列喷雾的新基础知识。这些设施将包括定制的透明喷嘴，以在喷嘴内进行成像测量。先进的诊断将与一套成熟的成像诊断（阴影，纹影，微型PIV）相结合，以关联的主要破碎流动力学与其相应的破碎发生在喷嘴内。PRIME将在知识方面提供实质性突破，并将生成一个全面的喷雾数据库，旨在为更广泛的喷雾界开发和验证计算模型。因此，PRIME旨在取得长期成功。

Efficient spray atomization plays a critical role within society, ranging from effective medical treatment to cleaner propulsion systems. Primary breakup - the process of disintegrating a liquid stream into large (primary) drops - is the consequential first step of atomization, but is also the least understood for atomizing sprays. This long-standing problem exists due to a lack of experimental tools that can measure the fundamental fluid dynamics that govern the primary breakup processes at liquid-gas interfaces (LGI) at the core of the spray. PRIME is uniquely designed to address this problem. We have developed a unique set of advanced diagnostic tools that provide the exclusive capability to measure fluid velocity and acceleration at LGIs of the liquid jet and primary drops. These tools are a unique combination of pulse-burst Ballistic Imaging combined with wavelet-based Optical Flow (wOF). In PRIME, we establish our proof-of-concept tools, and develop wOF for original applications with two-photon laser induced fluorescence, to provide ground-breaking measurements that help resolve unanswered questions of primary breakup. Two spray facilities will be developed in PRIME, which provide a unique platform to apply our diagnostics for new fundamental knowledge for a range of sprays from basic to technically-relevant complex sprays. These facilities will include custom-built transparent nozzles to perform imaging measurements inside the spray nozzle. Advanced diagnostics will be combined with a suite of established imaging diagnostics (shadowgraphy, schlieren, micro-PIV) to correlate the primary breakup flow dynamics with its corresponding breakup genesis occurring inside the spray nozzle. PRIME will provide substantial breakthroughs in knowledge, and will generate a comprehensive spray database designed for the development and validation of computational models for the wider spray community. As such, PRIME is intended for long term success.