Experimental study of bluff-body stabilized highly turbulent premixed flames using pre-vaporized liquid fuels

本项目是一项用于推进应用的高湍流预混火焰的实验研究。高湍流度是许多推进系统在小空间内产生高功率的共同特征。关于高湍流度火焰相互作用的科学知识仍然缺乏。这项研究将有助于更好地理解使用关键喷气燃料的火焰-湍流相互作用。该团队将进行这项研究，为公众提供高质量的实验数据。这项研究的技术潜在好处将是更好地设计燃烧系统，以实现稳定运行和减少污染物。高效、低污染的燃烧系统将有利于环境和健康。该项目还通过培养高级博士研究生来促进高技能劳动力的发展。这项工作的目标是提高对高度湍流(接近流动中湍流强度高达40%，湍流雷诺数高达8100)中钝体锚定预混火焰的火焰稳定和稀薄喷吹特性的基本了解。将采用带有圆盘状火焰稳定器的倒锥形火焰结构。最先进的激光诊断技术(粒子图像测速仪和羟基和甲醛的同时平面激光诱导荧光)将被用来测量火焰结构/流场相互作用，使人们能够理解以前没有充分探索的高湍流燃烧模式。所得到的实验数据也将被用来验证使用大涡模拟(LES)方法的高保真数值模拟。使用预汽化液体燃料的新实验数据来记录和发展对预混燃烧中贫化喷吹现象的全面理解，因为它与强湍流、钝体回流区流动动力学和火焰-流动相互作用有关。这些数据还将包括波纹火炬和反应片的较高湍流区的火焰特性，而不需要引导火焰。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。

This project is an experimental investigation of highly turbulent premixed flames for propulsion applications. High level of flow turbulence is a common feature of many propulsion systems to generate high power in a small space. Scientific knowledge of flame interactions with high turbulence is still lacking. This study will contribute to better understanding of flame-turbulence interactions using key jet fuels. The team will conduct this research to provide high quality experimental data for public use. Technical potential benefits of this research will be better design of combustion systems for stable operation and pollutant reduction. High-efficiency and low-pollution combustion systems will benefit both environment and health. This project also contributes to the development of highly-skilled workforce by training advanced doctoral degree students.The goal of this work is to improve the fundamental understanding of flame stabilization and lean blowoff characteristics in bluff-body-anchored premixed flames in highly turbulent flow (with turbulence intensities up to 40% in the approaching flow and turbulence Reynolds numbers up to 8,100). An inverted conical flame configuration with a disk-shaped flame stabilizer will be employed. State-of-the-art laser diagnostics (particle image velocimetry and simultaneous planar laser induced fluorescence of hydroxyl and formaldehyde) will be utilized to measure the flame structure/flowfield interactions, enabling the understanding of high-turbulence combustion regimes that have not been fully explored before. The resulting experimental data will also be utilized for validation of high fidelity numerical simulations using large eddy simulation (LES) methodology. New experimental data for pre-vaporized liquid fuels are used to document and develop a comprehensive understanding of lean blowoff phenomena in premixed combustion as it relates to highly turbulent flow, bluff-body recirculation zone flow dynamics, and flame-flow interactions. These data will also include the flame properties in the higher turbulence regimes of corrugated flamelets and reaction sheets without the need for piloted flames.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.