Unraveling Hidden Physics in Multiphase Combustion: Preferential Vaporization at Elevated Pressure

运输液体燃料，如汽油、喷气燃料和柴油，含有数百个大小和化学结构差异很大的分子。因此，液体燃料的燃烧涉及燃料中各种分子所决定的化学反应速率和喷雾尺寸分布之间的复杂耦合。该项目的主要目的是建立燃料汽化过程的基本知识，特别是在与内燃机应用相关的高压条件下。该项目的成果将为开发下一代先进内燃机提供基础，从而减少排放，提高整体效率。该项目还将包括重要的教育活动，包括研究生和本科生研究计划，以及面向当地高中生和教师的外联计划，以履行NSF的使命。该项目将培养美国能源和工程科学领域的下一代创新者。拟议研究的目的是通过在高压条件下设计和执行定义明确的实验来建立优先汽化影响的基本知识，这些实验将用于验证和评估优先汽化子模型的保真度。该项目将执行三项实验任务和一项模拟任务：1)多组分燃料孤立单液滴汽化的实验表征；2)孤立单液滴与火焰相互作用的实验研究；3)通过明确定义的多组分燃料混合物控制燃料蒸发程度的接近极限燃烧行为的实验；4)能够描述优先汽化特性的喷雾子模型的开发和验证。该项目的成果有望为替代燃料及其合成方法的发展提供有洞察力的指导，并为开发先进的燃料规范协议奠定基础。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Transportation liquid fuels, such as gasoline, jet, and diesel fuels, contain hundreds of molecules with wide variations in their sizes and chemical structures. Consequently, the combustion of liquid fuels involves complex coupling between chemical reaction rates dictated by various molecules in the fuel and spray size distribution. The principal aim of this project is to establish fundamental knowledge of the fuel vaporization process, particularly at high-pressure conditions relevant to the applications of internal combustion engines. The outcomes of the project will provide a fundamental foundation for developing next-generation advanced combustion engines, allowing the reduction in emission as well as increase overall efficiency. The project will also encompass significant educational activities, including both graduate and undergraduate research programs and an outreach program geared towards local high school students and teachers to fulfill the mission of the NSF. The project will allow nurturing of the next generation of U.S. innovators in energy and engineering sciences. The goal of the proposed research is to establish fundamental knowledge of preferential vaporization impacts by designing and performing well-defined experiments at elevated pressure conditions, which will be used for validating and evaluating the fidelity of the sub-model of preferential vaporization. The project will perform three experimental tasks and one modeling task: 1) Experimental characterization of isolated single droplet vaporization for multi-component fuels; 2) Experimental investigation of isolated single droplet interaction with flames; 3) Experiments on near-limit combustion behaviors by controlling the extent of fuel vaporization with well-defined multi-component fuel mixtures; 4) Development and validation of spray sub-model capable of describing preferential vaporization characteristics. The results of this project are expected to provide insightful guidance to the development of alternative fuels and their synthetic methodologies and a fundamental foundation to develop advanced fuel specification protocol.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.