CSAR Noon Seminar
Joseph M. Powers
Department of Aerospace and Mechanical Engineering
University of Notre Dame
DATE: Wednesday, March 22, 2000
TIME: 12:00 Noon
PLACE: 2240 DCL
TITLE: Resolved Viscous Detonation in H_2/O_2/Ar Using
Instrinsic Low-Dimensional Manifolds and Wavelet Adaptive Multilevel
Representation
ABSTRACT
A standard ignition delay problem for a mixture of hydrogen, oxygen, and
argon in a shock tube is extended to the viscous regime and solved using
the method of Intrinsic Low-Dimensional Manifolds (ILDM) coupled with a
Wavelet Adaptive Multilevel Representation (WAMR) spatial discretization
technique. An operator splitting method is used to describe the reactions
as a system of ordinary differential equations at each spatial point.
The ILDM method is used to eliminate the stiffness associated with the
chemistry by decoupling processes which evolve on fast and slow time
scales. The fast time scale processes are systematically equilibrated,
thereby reducing the dimension of the phase space required to describe
the reactive system. The WAMR captures the detailed spatial structures
automatically with a small number of basis functions thereby further
reducing the number of variables required to describe the system. Using a
maximum of only 300 collocation points and 15 scale levels allows results
with striking resolution of fine scale viscous and induction zones to be
obtained. Additionally, the resolution of physical diffusion processes
minimizes the effects of potentially reaction-inducing artificial entropy
layers associated with numerical diffusion.