Modeling of Strong Shock Waves from Explosions: Not with a Whimper but a Bang

date October 30, 2016
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Friday, November 4, 2016
4:00 p.m. in ETC 4.150

Professor Won-Suk Ohm
School of Mechanical Engineering
Yonsei University
Seoul, South Korea
http://web.yonsei.ac.kr/acoustics

Blast waves produced by such events as nuclear explosions are considered as “strong” shock waves, the description of which requires a theoretical framework more accurate than the second-order models such as the weak-shock theory and the Burgers equation. In order to study strong shock waves, computational fluid dynamics (CFD), based on the Euler equation, is frequently used. However, CFD is highly time-consuming especially for blast waves traveling over long propagation distances. In this talk, a fast computational method for solving the Euler equation is presented, which was recently devised by the author and his students at Yonsei University. The method is based on the Riemann solver of Godunov, in which a waveform is discretized into a series of discontinuities. Our departure from Godunov is that these discontinuities are regarded as particle-like entities (dubbed “Hugonions” by the author), which travel, interact with each other, and most importantly, annihilate. Comparison of the method with traditional Riemann solvers and the Burgers equation is given to showcase its relative accuracy and savings in computation time.