Universal Mechanism of Turbulence-Induced Deflagration-to-Detonation Transition from Terrestrial Chemical Systems to Supernovas

预测和控制爆震波（即燃烧驱动冲击波）的开始的努力对于研究界来说是一个严峻的挑战，并且对于爆震可能是有益的或有害的广泛应用来说是重要的。在密闭空间中，通过与可压缩波或冲击波的相互作用，低速爆燃或层流火焰可以自然地发展成爆炸。然而，在开放空间中，从低速爆燃波到爆轰波的转变机制仍然不清楚。这项研究的结果可以应用于新的发电和推进系统的开发，例如，燃气涡轮机发动机和旋转爆震发动机（RDE），采矿作业、燃料储存、化学处理和核发电设施的工业安全，以及诸如超新星爆炸的无限天体物理系统。此外，这项工作将通过培养下一代科学家和工程师成为湍流反应流的领导者而产生更广泛的影响。参与研究和教育的学生将了解湍流在提高燃烧系统效率方面的作用。总体目标是通过推广，学习和专业教育来推动学生在STEM学科的成长。这项研究探索了一种新的机制，通过这种机制，快速湍流火焰可以变得本质上不稳定，甚至在完全开放的环境中自发地过渡到爆震。本计画的目标是发展对紊流火焰的自发失控机制，以及紊流诱发燃烧转爆轰（TDDT）的全面了解。本文将在一个独特的“湍流激波管”（TST）装置上对可压缩湍流火焰的失控机理进行实验研究。先进的超快激光诊断技术用于调查。该研究涉及高速可压缩湍流火焰和燃烧的几项新研究，这些研究是许多现代能源和推进系统的基础，例如燃气涡轮/内燃机到超燃冲压发动机和旋转爆震发动机（RDES），到爆炸恒星。该奖项反映了NSF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而被认为值得支持。

Efforts to predict and control the onset of detonation waves, i.e. combustion driven shock waves, have been a serious challenge for research community and is important for a wide range of applications where detonations can be beneficial or harmful. In confined spaces, detonations can naturally develop from low-speed deflagration or laminar flames through interactions with compressible or shock waves. However, in unconfined spaces the mechanism of transition from a low speed deflagration wave to a detonation wave remains unclear. Findings from this research can apply to development of new power generation and propulsion systems, e.g., gas turbine engines and Rotating Detonation Engines (RDEs), and industrial safety of mining operations, fuel-storage, chemical processing, and nuclear power-generation facilities, as well as unbounded astrophysical systems such as supernova explosions. Additionally, this work will have a broader impact by preparing next generation of scientists and engineers to be leaders in turbulent reacting flows. Students involved in the research and education will understand the role of turbulence in improving the efficiency of combustion-based systems. The overarching goal is to drive student growth in STEM disciplines through outreach, learning, and professional education. This research explores a novel mechanism through which fast turbulent flames can become intrinsically unstable and spontaneously transition to a detonation even in completely unconfined environments. The goal of this project is to develop a comprehensive understanding of the spontaneous runaway mechanism of turbulent flames, and Turbulence-induced Deflagration-to-Detonation Transition (TDDT). The runaway mechanism of compressible turbulent flames will be experimentally explored in a unique “Turbulent Shock Tube” (TST) facility. Advanced ultra-fast laser diagnostic techniques are used for the investigation. The research entails several novel studies of high-speed compressible turbulent flames and combustion that is fundamental to many modern energy and propulsion systems, such as gas-turbine/internal-combustion engines to scramjets and rotating detonation engines (RDEs), to exploding stars.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.