CAREER: Understanding the Influence of Thermal Radiation on the Ignition and Propagation of Dust Explosions

几个世纪以来，粉尘爆炸一直是重大危险，很可能是从人类开始储存粮食以来。煤矿、食品加工设施、金属加工厂甚至日常生活中的爆炸事件时有发生，令人震惊。尽管有很长的研究历史，但支配尘埃爆炸及其结构的物理机制仍然相对未知。即使在今天，关于产生自我维持的尘埃爆炸的控制过程是什么，仍然存在激烈的科学辩论。基本问题，如辐射热传递对尘埃爆炸的影响，仍然没有答案。这项研究项目将使用尖端的数值模拟来获得对尘埃爆炸的基本了解，特别是热辐射在其引发和传播中的作用。从该项目中获得的基本理解将为安全工程师提供更好的知识，最终可用于制定改进的爆炸缓解策略、安全设备和法规，以保护社会免受危险粉尘爆炸的影响。这项研究项目将利用公众对电影中爆炸的迷恋，对来自代表性不足群体的不同青年群体进行STEM推广。该项目的研究人员将与佛罗里达大学学前教育和培训中心合作，每年夏天与高中生合作。暑期高中生将接触到STEM劳动力所需的关键技能，包括高性能计算、数值模拟和数学。通过每年向暑期学生讲授粉尘爆炸和相关现象，提高公众对可燃粉尘危害的认识。本研究项目将使用最先进的颗粒多相模型、辐射近似和数值模拟技术来研究热辐射对粉尘爆炸的影响。通过求解辐射传递方程，将热辐射直接耦合到颗粒反应多相流方程中。这些模拟将系统地探索热辐射如何影响层流尘埃火焰的传播，层流尘埃火焰的点火，以及现实多维情景中尘埃爆炸和湍流尘埃火焰的启动和传播。粉尘爆炸的引发和传播场景包括粉尘火焰在封闭管道中的传播、激波和反应性粒子云相互作用以及分层粉尘爆炸。数值模拟包括有机和金属粉尘颗粒，以比较和对比它们的爆炸特性。此外，还将探讨模拟结果对化学和辐射模型中细节水平的敏感性。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。

Dust explosions have been significant hazards for centuries, likely since humankind began storing grain. Explosions in coal mines, food processing facilities, metal working factories, and even everyday life occur with alarming regularity. Despite a long history of research, the physical mechanisms that govern dust explosions and their structure remain relatively unknown. Even today, there is vigorous scientific debate on what are the controlling processes that produce self-sustaining dust explosions. Basic questions, such as the influence of radiative heat transfer on dust explosions, remain unanswered. This research project will use cutting edge numerical simulations to gain a fundamental understanding of dust explosions and, in particular, the role of thermal radiation on their initiation and propagation. The fundamental understanding gained from this project will provide safety engineers with improved knowledge that ultimately can be used to develop improved explosion mitigation strategies, safety devices, and regulations to protect society from hazardous dust explosions. This research project will leverage the public fascination with explosions in movies to do STEM outreach to a diverse pool of youths from underrepresented groups. The project researchers will partner with the University of Florida Center for Precollegiate Education and Training to work with high-school students each summer. The high-school summer students will be exposed to critical skills needed for the STEM workforce, including high-performance computing, numerical simulation, and mathematics. Public awareness on the hazards of combustible dust will be raised by giving lectures to summer students every year on dust explosions and related phenomena.This research project will study the influence of thermal radiation on dust explosions using state-of-the-art granular multiphase models, radiation approximations, and numerical simulation techniques. Thermal radiation will be directly coupled to the granular reactive multiphase flow equations by solving the radiation transfer equation. The simulations will systematically explore how thermal radiation influences the propagation of laminar dust flames, the ignition of laminar dust flames, and the initiation and propagation of dust explosions and turbulent dust flames in realistic multidimensional scenarios. The scenarios for the initiation and propagation of dust explosions include the propagation of dust flames in closed tubes, shock and reactive particle cloud interactions, and layered dust explosions. The numerical simulations include both organic and metallic dust particles to compare and contrast their explosion characteristics. In addition, the sensitivity of the simulation results to the level of detail in the chemical and radiation models will be explored.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.