CSAR Noon Seminar

Fady Najjar, UIUC/CSAR

DATE: Wednesday, November 12, 2003
TIME: 12:00 Noon
PLACE: 2240 DCL
1304 W. Springfield Ave., Urbana, IL

TITLE: Perspectives on Multiphase Flow Simulations

ABSTRACT

This talk focuses on simulations of multiphase flows pertinent to solid-propellant rocket motors. Modern propellants have aluminum particles added to the mix. The burning of Al droplets accounts for up to 30% of the heat generation. Our interest resides in the design and development of a comprehensive computational approach that includes both the burning aluminum particles and the resulting oxide smoke. We follow the aluminum droplets as they are injected from the propellant combustion interface (PCI), accelerated across the rocket chamber, and through a CD nozzle exiting at supersonic speeds. The oxide smoke is treated as a continuum and its concentration is followed over time as well.

We will describe the multiphase flow framework (Rocfluid) consisting of a Lagrangian combusting particle tracking module working in concert with an Eulerian fluid solver, an LES turbulence model, and an Equilibrium Eulerian module for the smoke. The highly parallel implementation permits us to solve for millions of fluid cells while tracking several millions of aluminum droplets. Further, we will describe preliminary results for basic multiphase flow applications including a shear flow past an aluminium particle sitting on a wall.

BIOGRAPHY

Dr. Najjar is a Principal Research Scientist at the Center for Simulation of Advanced Rockets (CSAR) at the University of Illinois at Urbana-Champaign (UIUC). He received a Ph.D. in Mechanical Engineering from UIUC in 1994. He was awarded a postdoctoral fellowship from the Division of Advanced Scientific Computing at the National Science Foundation in residence at NCSA. He then joined Thinking Machines Corporation and subsequently Silicon Graphics as a Research Application Engineer. His areas of interests include multiphase flows, large-eddy simulations (LES), turbulence modeling, and high-performance computing.