Theory of Vorticity Generation by Shock Wave and Flame Interactions
Abstract
We present detailed numerical and theoretical studies of vorticity generation by the interaction of a weak planar shock with an azimuthally symmetric flame. The calculations are two-dimensional and correspond to a cylindrical flame. To analyze the fluid-dynamic aspects of the problem, we exclude chemical reactions and model the flame as a region of reduced density and elevated temperature. We find that the rotational flows associated with the vorticity distribution are long-lived and can produce a significant distortion of the heated region. The results of our numerical simulations and the estimates of the nonlinear theory are quite consistent. We also compare the nonreactive numerical simulations with the experimental data of Markstein on shock wave and flame interactions in a stoichiometric mixture of n-butane and air. The numerical simulations reproduce most of the major experimental observations. We show that conventional Rayleigh-Taylor instability theory, which assumes a very small initial perturbation, does not provide a viable description of vorticity generation in Markstein's experiment. Instead, a nonlinear treatment based on the finite misalignment and finite interaction time of the pressure gradient associated with the shock and the density gradient of the flame is necessary. The effects of chemical reactions are also clarified through the comparison of numerical simulation and experiment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 05, 1984
- Accession Number
- ADA144432
Entities
People
- Elaine Oran
- J. Michael Picone
- Jay Paul Boris
- T. R. Young Jr.
Organizations
- United States Naval Research Laboratory