Shock-Tube Studies of High-Temperature Flames Applicable to Next-Generation Energy Systems

满足社会日益增长的能源需求，同时确保可靠和公平的能源获取，并减轻能源生产对加剧气候变化的作用，需要一项全面的研究和技术开发战略。化学燃料的燃烧仍然是发电和运输部门使用的主要能源转换技术，预计在未来几十年将继续使用，特别是在商业航空和航运等“难以电气化”的部门。下一代基于燃烧的能源系统使用可持续的净零碳燃料，结合先进的热力学循环，以最大限度地提高能量转换效率，为燃烧系统的持续使用提供了一条途径，同时减轻了历史上与燃烧系统相关的不利影响。该项目通过对与实际燃烧应用相关的高温条件下火焰行为的基础研究，为下一代能源系统的开发提供支持。先进的实验技术、高速成像和基于激光的诊断将提供在受控实验室环境中研究的最高温度条件下火焰速度和结构的详细测量。这些测量的可用性将为燃烧过程的准确建模和模拟提供信息，并缩短部署下一代能源系统所需的开发时间，减少碳排放。预混合层流火焰速度是燃料-氧化剂系统的一个基本特性。层流火焰速度由热、输运和化学动力学性质共同控制，它包含了通常用来描述燃烧事件的详细模型的多个组成部分的信息。实验测量的火焰速度被广泛用作动力学机制发展各个阶段的性能指标，包括调整参数，验证全局性能，并在机制缩小尺寸以用于实际燃烧系统的详细模拟时保持准确性。激波管火焰速度方法已经得到了发展和完善，可以研究与下一代能源系统相关的高温反应条件下的层流火焰，但使用以前的测量技术无法进行实验研究。该项目的活动1是应用激波管火焰速度方法，对与当前和未来能源系统相关的燃料在高温下的层流火焰速度测量进行调查。这些测量将被整理到一个新的测量数据库中，以确保结果数据的简单和开放访问。该项目的活动2将包括先进诊断的探索性应用，以确定和研究高温下存在的新型火焰结构和现象，如冷火焰、双火焰和过度驱动火焰。该项目产生的数据将作为高温火焰行为的第一个基本实验测量，因此有望显著推进对实际能量转换系统相关条件下燃烧现象的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Meeting society’s growing energy demands while simultaneously ensuring reliable and equitable energy access and mitigating the role of energy production on exacerbating climate change requires a holistic research and technology-development strategy. The combustion of chemical fuels remains the primary energy conversion technology used in the power generation and transportation sectors and is projected to persist for decades to come, particularly in “hard to electrify” sectors such as commercial aviation and shipping. Next-generation combustion-based energy systems using sustainable, net-zero-carbon fuels together with advanced thermodynamic cycles to maximize energy conversion efficiency provide a pathway for the continued use of combustion systems while mitigating the adverse effects with which they have historically been associated. This project provides support to the development of next-generation energy systems through fundamental studies of flame behavior at high-temperature conditions relevant to practical combustion applications. Advanced experimental techniques and high-speed imaging and laser-based diagnostics will provide detailed measurements of flame speeds and structure at the highest temperature conditions ever studied in a controlled laboratory environment. The availability of such measurements will inform the accurate modeling and simulation of combustion processes and shorten the development time required for the deployment of next-generation energy systems with reduced carbon emissions.The premixed, laminar flame speed represents a fundamental property of a fuel-oxidizer system. Jointly governed by thermal, transport, and chemical-kinetic properties, the laminar flame speed contains information on multiple components of the detailed models commonly compiled to describe combustion events. Experimentally measured flame speeds are widely utilized as performance metrics in all stages of kinetic mechanism development, including tuning the parameters, validating the global performance, and maintaining accuracy as mechanisms are reduced in size for use in detailed simulation of practical combustion systems. The shock-tube flame speed method has been developed and refined to enable the study of laminar flames at high-temperature, reactive conditions relevant to next-generation energy systems but beyond the capability of experimental study using previous measurement techniques. Activity 1 of this project is to apply the shock-tube flame speed method to perform a survey of laminar flame speed measurements at high temperatures for fuels relevant to current and future energy systems. These measurements will be collated into a new measurement database to ensure simple and open access of the resulting data. Activity 2 of this project will include the exploratory application of advanced diagnostics to determine the presence of and study novel flame structures and phenomena existing at high temperatures, such as cool, double, and overdriven flames. Data resulting from this project will serve as the first fundamental experimental measurements of high-temperature flame behavior and are thus expected to significantly advance the understanding of combustion phenomena at conditions relevant to practical energy-conversion systems.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.