The International Conference for High Performance Computing, Networking, Storage and Analysis
Understanding the Physics of the Deflagration-to-Detonation Transition.
Authors: Alexei Poludnenko (Naval Research Laboratory), Elaine Oran (Naval Research Laboratory), Christopher Lewis (Lockheed Martin / HPCMP Data Analysis and Assessment Center), Miguel Valenciano (Data Management Consultants / HPCMP Data Analysis and Assessment Center)
Abstract: An astronomical phenomenon known as the Type Ia supernovae (SN Ia) results from the thermonuclear incineration of compact, degenerate, white dwarf stars. When a close-by stellar companion is present, white dwarfs can end their life in one of the most powerful explosions in the Universe. The resulting energy release and the associated fluid expansion produce turbulent motions, which wrinkle and fold the flame, accelerating burning significantly. Turbulent flame acceleration alone, however, is often not sufficient to explain the power of these explosions. The missing piece could be the deflagration-to-detonation transition (or DDT), in which a subsonic flame develops a supersonic shock-driven reaction wave. Elucidating the physics of DDT, as well as the conditions that can lead to it, would be important for a broad range of problems from the safety of fuel storage and chemical processing facilities to the nature of the SN Ia phenomenon and of the enigmatic dark energy. The study of detonation wave concepts for propulsion applications is promising. An increase in fuel efficiency of up to 25% is possible.
Since the conditions required for the onset of DDT were not known, a survey of a large parameter space was required. The largest calculations had the computational grid size of up to 1 billion cells. The overall number of time-steps per calculation reached ~1014 cell-steps. The total CPU cost of each calculation ranged from 100,000 to 500,000 CPU hours.