Professor David Frost was the honored speaker at the 2023 Spring 2023 Yunchuan Aisinjioro-Soo Distinguished Lecture, held April 20 in the National Center for Supercomputing Applications (NCSA) Auditorium.
Frost is a professor of mechanical engineering at McGill University in Montreal, Quebec, Canada. His lecture was titled “Instabilities in Explosively Driven Dense Gas-Particle Flows: Volcanic Eruptions, Meteorite Clouds, and Multiphase Explosives.”
Abstract: When a layer of particles or liquid is explosively accelerated, the dispersed material typically forms coherent jet-like structures that are aerodynamically stable. Such particle jets are observed at a range of scales in natural phenomena, from the ash jets observed during Plinian volcanic eruptions, to particle jets that form in supernova remnants at astrophysical scales. In the generic problem of a shock wave interacting with a group of particles, the non-uniform particle distribution characteristic of the resulting high-speed gas-particle flow can result from a variety of mechanisms. For weak gas shocks, particle jets may form due to a multiphase hydrodynamic instability, often denoted the shock-driven multiphase instability. This instability is related to other classical hydrodynamic interfacial instabilities (such as the Rayleigh-Taylor and Richtmyer-Meshkov instabilities) but has distinct features due to the transfer of momentum and energy between the phases. If particles or liquids are accelerated by the strong shocks (GPa pressures) characteristic of condensed explosives, particle filaments and jets are also typically formed. However, in this case, Frost said it is not the strong shock wave, but rather the expansion wave that returns from the free particle surface, which plays the key role in the jet formation. He illustrated some of the above phenomena from a variety of experimental studies and highlighted some of the outstanding issues that need to be resolved to model the multiphase flows.
Frost’s research interests are in the areas of metal combustion, multiphase combustion processes and shock wave physics. For the last few decades, he has been studying the combustion of dust clouds, blast waves from metalized explosives, and the reaction of metal fuels with air and water as a carbon-free energy source.
The Yunchuan Aisinjioro-Soo Distinguished Lecture was established in 1992 by Professor Shao Lee Soo and his wife, Hermia. Professor and Mrs. Soo sought to perpetuate the memory of his mother, Yunchuan Aisinjioro-Soo (1899-1991). Born Princess Shansji of Aisinjioro, the last Royal House of China, she took the pen name Yunchuan and became an accomplished poet and artist. Throughout the turmoil of revolution and war, she steadfastly believed that the way for the family to serve the people is through the education of its children.
Two of the Soos’ three children – David Soo and Shirley Soo – attended the lecture, along with a grandson, Michael Soo, an alumnus of MechSE and a frequent research collaborator of MechSE’s Shao Lee Soo Professor Nick Glumac.