CAREER: Elucidating Fuel Spray Atomization Physics: Setting a Path for High-Efficiency Clean Combustion

1653687 genzale本项目将开发一种新的实验方法，用于在实际燃烧相关环境下测量燃料喷雾特性。这项工作对高效清洁内燃机的发展至关重要。这些测量将把我们对燃料喷雾的理解从经验转变为基础，因为在实际燃烧条件下，喷雾破裂的物理机制尚未被测量或证实。确定燃油喷雾雾化的控制机制将有助于研究人员开发更精确的计算机模型，这将被用作发现新的高效清洁燃烧策略的预测工具。该项目的教育活动旨在鼓励女性更广泛地参与研究事业，并培养一支多样化的工程人才队伍，他们能够创新我们未来世界将依赖的重大挑战解决方案。本课题的主要研究目标是：1)测量与燃烧相关条件下雾化高压燃油喷雾的联合液滴Sauter average Diameter （SMD）和液体体积分数场；2)验证关于高压燃油喷雾中导致界面不稳定和射流破裂的物理机制的未验证的文献假设，包括气动力、液体湍流、空化和/或孔板流动效应。研究方法的重点是采用一种新的最先进的高压光学可达燃烧室，最近在乔治亚理工学院的实验室得到了机构的支持，该燃烧室可以在高达100巴和900 K的条件下进行光学喷雾和燃烧测量。开发了一种双波长层析消光测量方法，以实现在燃烧相关条件下同时测量实际燃料喷雾中液滴SMD和液体体积分数分布的三维测量。通过测量控制孔板几何形状和燃料特性，在广泛的环境气体密度条件下，对燃油喷雾控制雾化机制进行假设测试。

1653687 GenzaleThis project will develop a new experimental method for measuring fuel spray properties under practical combustion-relevant environments. This work is critical for the advancement of high-efficiency clean combustion engines. These measurements stand to transform our understanding of fuel sprays from empirical to fundamental, because the physical mechanisms of spray breakup under practical combustion conditions have yet to be measured or proven. Determination of the governing mechanisms of fuel spray atomization will help researchers develop more accurate computer models, which will be used as a predictive tool for the discovery of new high-efficiency clean combustion strategies. Educational activities in this project aim to encourage broader participation of women in research careers and to develop a diverse engineering workforce who can innovate the grand challenge solutions that our future world will depend on.The primary research objectives of this proposal are to: 1) measure the joint droplet Sauter Mean Diameter (SMD) and liquid volume fraction field of atomized high-pressure fuel sprays under combustion-relevant conditions, and 2) test un-validated literature hypotheses on the physical mechanisms that lead to interface instabilities and jet breakup in high-pressure fuel sprays, including aerodynamic forces, liquid turbulence, cavitation, and/or orifice flow effects. The research approach is centered on the employment of a new state-of-the-art high-pressure optically-accessible combustion chamber recently commissioned within my laboratory at Georgia Tech via institutional support, which enables optical spray and combustion measurements at up to 100 bar and 900 K. A two-wavelength tomographic extinction measurement is developed to enable simultaneous 3-D measurements of droplet SMD and liquid volume fraction distribution in practical fuel sprays under combustion-relevant conditions. Hypothesis testing of the governing atomization mechanisms in fuel sprays is conducted via measurements with controlled orifice geometry and fuel properties over a wide range of ambient gas density conditions.