Multiphase Reactive Flows: From Dust Explosions to Metal-Fueled Detonations

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Explosions in coal mines, metal-processing facilities, and other industrial settings occur with alarming regularity, while reactive metal particles are being considered for energy-storage and propulsion applications. Despite a long history of research and its importance to safety and propulsion applications, the physical mechanisms that govern the ignition, combustion, and detonation of reactive particles remain relatively unknown. Basic questions such as “How do particle size and thermal radiation affect dust-explosion propagation?”, “What mechanisms govern the ignition and combustion of shock-dispersed metal powders?”, and “How can reactive particles modify or sustain detonation waves?” remain unanswered. This presentation will discuss an ongoing numerical simulation effort aimed at answering these and other fundamental questions. This problem is addressed by solving a set of equations that couples a fully compressible reacting gas to a granular multiphase model that accounts for particle motion, interphase drag and heat transfer, and particle combustion. The results of these simulations indicate that shock propagation, particle dispersal, ignition, combustion, and thermal radiation are tightly coupled in a highly dynamic process. Results discussing the influence of particle diameter and thermal radiation on layered coal-dust explosions and the ignition and combustion of TNT-dispersed aluminum powder will be discussed. The presentation will close by discussing recent work exploring hybrid aluminum–hydrogen–air detonations, including the role of particle size in extending detonation limits and modifying detonation structure.

Speaker: Dr. Guhathakurta

Biography: 

Dr. Guhathakurta received an M.Sc. degree in Physics from the Indian Institute of Technology Delhi, and M.S. and Ph.D. degrees in Aerospace Engineering from the University of Florida. He subsequently held a postdoctoral appointment at Eindhoven University of Technology in the Netherlands. Dr. Guhathakurta is currently an Assistant Professor in the Department of Aerospace Engineering at Texas A&M University. His research focuses on a wide range of topics in multiphase reactive flows, combustion, and numerical simulation, including dust explosions, hybrid detonations, thermal-radiation effects, metal-particle combustion, and high-speed propulsion.