ERI: High-pressure spectroscopy of ammonia combustion species for carbon-free supercritical and detonative power and propulsion

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。随着美国交通和发电行业向低碳未来过渡，以减少对环境的影响并增强美国的能源安全，在极端压力下更有效的能源转换变得越来越重要。不幸的是，氨等无碳燃料的极压燃烧还没有得到很好的理解。该项目的主要目标是通过测量在受控点火实验中形成的重要燃烧气体，并以足够快的测量速度来捕捉许多短暂气体的行为，从而更好地了解高压氨的化学反应。为了进行这些测量，将开发一种新的激光诊断技术，以比以往任何时候都更高的压力和更快的测量速度来测量这些气体。该项目的成功实施将提供(1)在极端压力下测量氨燃烧气体的新诊断工具，在能源和火箭推进系统中有更广泛的应用，以及(2)对高温和高压下污染形成的新理解。预计从该项目中获得的知识将有助于加快美国无碳发电技术的发展。该项目还将在UTSA建立最先进的燃烧研究能力，UTSA是一家与美国能源和航空航天行业关系密切的少数族裔服务机构，互补的教育活动将通过相关的实验室研究项目加强UTSA新兴的航空航天课程。这项提议的研究目标是利用非理想光谱现象来测量下一代无碳燃料，尤其是氨的超临界和爆震燃烧流动。拟议的研究结合了低成本紧凑中红外光子学的进步和物理信息的光谱模型，以定量解释在测量速率下原本复杂的高压吸收光谱，该测量速率充分捕捉到超临界和爆震区域中中间物质的时间演化。在本项目中，将使用加热光学气体室和高焓激波管来研究氨燃烧气体的高压吸收光谱。将开发热力学可缩放模型，以预测这些物种在与爆震和超临界燃烧相关的温度和压力下的吸收光谱。这些模型随后将被用于在UTSA的激波和爆轰管中对氨混合物在超临界点火和爆轰燃烧过程中的目标物种进行新的高速定量测量。在项目过程中收集的数据将被纳入UTSA的研究生和本科工程课程，以更好地为学生在工程工作中进行下一代研究和开发做准备。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 award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). More efficient energy conversion at extreme pressures is increasingly important as both the U.S. transportation and power generation sectors transition to a low-carbon future to reduce environmental impact and increase U.S. energy security. Unfortunately, extreme-pressure combustion of carbon-free fuels, such as ammonia, is not well-understood. The main goal of this project is to better understand chemical reactions of high-pressure ammonia by measuring important combustion gases formed during controlled ignition experiments, and at fast enough measurement rates to capture the behavior of many short-lived gases. To perform these measurements, a new laser diagnostic technique will be developed to measure these gases at higher pressures and faster measurement rates than ever before. Successful execution of the project will provide (1) new diagnostic tools for measuring ammonia combustion gases at extreme pressures, with broader application to both energy and rocket propulsion systems, and (2) new understanding of pollution formation at high temperatures and pressures. It is envisioned that knowledge gained from this project will help accelerate development of carbon-free power generation technologies in the U.S. The project will also build state-of-the-art combustion research capability at UTSA, a Minority Serving Institution with close proximity to U.S. energy and aerospace industries, and complementary educational activities will enhance UTSA’s emerging aerospace curriculum with relevant laboratory research projects. The research objective of this proposal is to exploit non-ideal spectroscopic phenomena for measurement of supercritical and detonation combustion flows of next-generation carbon-free fuels, most specifically ammonia. The proposed research combines advancements in low-cost compact mid-infrared photonics with physics-informed spectroscopic models to quantitatively interpret otherwise convoluted high-pressure absorbance spectra at measurement rates which sufficiently capture time-evolution of intermediate species in supercritical and detonation regimes. In this project, high-pressure absorption spectroscopy of ammonia combustion gases will be investigated using both a heated optical gas cell and high-enthalpy shock tube. Thermodynamically scalable models will be developed to predict absorbance spectra of these species for temperatures and pressures relevant to detonation and supercritical combustion. The models will subsequently be used to perform novel high-speed quantitative measurements of the target species during supercritical ignition and detonation combustion of ammonia mixtures in shock and detonation tubes at UTSA. Data collected during the project effort will be incorporated into graduate and undergraduate engineering courses at UTSA to better prepare students for next-generation research and development in the engineering workforce.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.