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Multiphase Simulations of Shock-Particle Interactions In Complex Energetic Systems

Event Type
fluid mechanics
Department of Mechanical Science & Engineering
2005 Mechanical Engineering Laboratory (Deere Pavilion)
Sep 22, 2017   12:00 - 1:00 pm  
Dr. Fady Najjar, Lawrence Livermore National Laboratory
Holly Foster
Originating Calendar
MechSE Seminars


Multiphase Simulations of Shock-Particle Interactions In Complex Energetic Systems




Date & Time

Dr. Fady Najjar

Lawrence Livermore National Laboratory


Friday, September 22, 2017                    12:00 P.M.


2005 Mechanical Engineering Lab (Deere)





Understanding shock-particle interactions is fundamental for a variety of physics and engineering problems. Particle response to the shock-induced flow acceleration results in a large uncertainty, hindering the computational capability to predict such complex flow. Computational results will be discussed for various energetic materials (EM) under shock loading conditions. A multiphysics hydrodynamics computational framework is applied to study challenging problems. In this presentation, we will focus on metal-loaded explosives in blast environment. EMs have solid inert particles embedded in a matrix of explosives. The detonation generates strong shocks in condensed phase materials that, unlike lighter gases, are strong enough to produce large deformation of the particles as the incident shock evolves around the particle. A series of hydrodynamics simulations is performed where the particle-to-EM density ratio and impedance ratio are varied to consider heavier and lighter particles.


About the Speaker

Dr. Najjar is currently a physicist in Design Physics Division at LLNL. He received his Ph.D. in 1994 from the University of Illinois at Urbana-Champaign. He joined the DOE’s ASC/ASAP Center for Simulation of Advanced Rockets in 1998 where he was a Senior Research Scientist, developing computational tools to study the Space Shuttle Solid Rocket Boosters. He then joined LLNL in 2007 as a code physicist working on the hydrodynamics code, ALE3D. He is an AIAA Associate Fellow and a member of APS, ASME, and SIAM. Dr. Najjar is the recipient of two 2014 Defense Programs Awards of Excellence and one 2015 Defense Programs Awards of Excellence. His research interests include multiphase flows, turbulence, shock dynamics, Uncertainty Quantification, and hybrid parallel algorithms for large-scale multiphysics codes.


LLNL-ABS-736462. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344



Host:   Professor Jon Freund

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