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害，可能是自人类开始储存粮食以来。在煤矿、食品加工厂、金属加工厂，甚至日常生活中，爆炸都以惊人的规律发生。尽管研究历史悠久，但控制粉尘爆炸的物理机制及其结构仍然相对未知。即使在今天，对于什么是产生自我维持的粉尘爆炸的控制过程，仍然存在着激烈的科学辩论。一些基本问题，如辐射热传递对粉尘爆炸的影响，仍然没有答案。该研究项目将使用最先进的数值模拟来获得对粉尘爆炸的基本了解，特别是热辐射对其启动和传播的作用。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，最终可用于开发改进的爆炸缓解策略，安全装置和法规，以保护社会免受危险粉尘爆炸的影响。这个研究项目将利用公众对电影爆炸的迷恋，对来自代表性不足群体的各种青年进行STEM推广。该项目的研究人员将与佛罗里达大学预科教育和培训中心合作，每年夏天与高中生一起工作。高中暑期学生将接触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。为了提高公众对可燃性粉尘危害的认识，每年为暑期学生举办粉尘爆炸及其相关现象的讲座。本研究项目将利用最先进的颗粒多相模型、辐射近似和数值模拟技术，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。模拟将系统地探讨热辐射如何影响层流粉尘火焰的传播，层流粉尘火焰的点燃，以及粉尘爆炸和湍流粉尘火焰在现实多维场景中的启动和传播。粉尘爆炸的起始和传播的场景包括粉尘火焰在封闭管道中的传播、冲击波和反应性粒子云的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，比较和对比它们的爆炸特性。此外，模拟结果对化学和辐射模型细节水平的敏感性也将被探讨。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，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.