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

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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.