Accession Number : ADA290869

Title :   On the Dynamics of a Shock-Bubble Interaction.

Descriptive Note : Final rept.,

Corporate Author : INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Personal Author(s) : Quirk, James J. ; Karni, Smadar

PDF Url : ADA290869

Report Date : SEP 1994

Pagination or Media Count : 39

Abstract : We present a detailed numerical study of the interaction of a weak shock wave with an isolated cylindrical gas inhomogeneity. Such interactions have been studied experimentally in an attempt to elucidate the mechanisms whereby shock waves propagating through random media enhance mixing. Our study concentrates on the early phases of the interaction process which are dominated by repeated refractions and reflections of acoustic fronts at the bubble interface. Specifically, we have reproduced two of the experiments performed by Haas and Sturtevant: Ms = 1.22 planar shock wave, moving through air, impinges on a cylindrical bubble which contains either helium or Refrigerant 22. These flows are modelled using the two-dimensional, compressible Euler equations for a two component fluid (air-helium or air-Refrigerant 22). Although simulations of shock wave phenomena are now fairly commonplace, they are mostly restricted to single component flows. Unfortunately, multi-component extensions of successful single component schemes often suffer from spurious oscillations which are generated at material interfaces. Here we avoid such problems by employing a novel, nonconservative shock-capturing scheme. In addition, we have utilized a sophisticated adaptive mesh refinement algorithm which enables extremely high resolution simulations to be performed relatively cheaply. Thus we have been able to reproduce numerically all the intricate mechanisms that were observed experimentally (e.g. transition from regular to irregular refraction, cusp formation and shock wave focusing, multi-shock and Mach shock structures, jet formation, etc), and we can now present an updated description for the dynamics of a shock-bubble interaction. (AN)

Descriptors :   *SHOCK WAVES, *BUBBLES, ALGORITHMS, COMPUTERIZED SIMULATION, EXPERIMENTAL DATA, INTERACTIONS, COMPARISON, AIR FLOW, COMPUTATIONAL FLUID DYNAMICS, FLOW VISUALIZATION, HIGH RESOLUTION, GAS DYNAMICS, MESH, COMPRESSIBLE FLOW, CYLINDRICAL BODIES, COMPUTER GRAPHICS, HETEROGENEITY, HELIUM, EULER EQUATIONS, REFRACTION, NUMERICAL METHODS AND PROCEDURES, OSCILLATION, SPURIOUS EFFECTS.

Subject Categories : Fluid Mechanics
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE