Observation and modeling of mixing-layer development in high-energy-density, blast-wave-driven shear flowa)

In this work, we examine the hydrodynamics of high-energy-density (HED) shear flows. Experiments, consisting of two materials of differing density, use the OMEGA-60 laser to drive a blast wave at a pressure of ∼50 Mbar into one of the media, creating a shear flow in the resulting shocked system. The interface between the two materials is Kelvin-Helmholtz unstable, and a mixing layer of growing width develops due to the shear. To theoretically analyze the instability's behavior, we rely on two sources of information. First, the interface spectrum is well-characterized, which allows us to identify how the shock front and the subsequent shear in the post-shock flow interact with the interface. These observations provide direct evidence that vortex merger dominates the evolution of the interface structure. Second, simulations calibrated to the experiment allow us to estimate the time-dependent evolution of the deposition of vorticity at the interface. The overall result is that we are able to choose a hydrodynamic model for the system, and consequently examine how well the flow in this HED system corresponds to a classical hydrodynamic description.

[1]  R. P. Drake,et al.  A design of a two-dimensional, supersonic KH experiment on OMEGA-EP , 2013 .

[2]  E. Johnsen,et al.  Discontinuous Galerkin method for multifluid euler equations , 2013 .

[3]  R. P. Drake,et al.  Measurements of turbulent mixing due to Kelvin–Helmholtz instability in high-energy-density plasmas , 2013 .

[4]  R. P. Drake,et al.  A design of a two-dimensional, multimode RM experiment on OMEGA-EP , 2013 .

[5]  O A Hurricane,et al.  Validation of a turbulent Kelvin-Helmholtz shear layer model using a high-energy-density OMEGA laser experiment. , 2012, Physical review letters.

[6]  R. P. Drake,et al.  Three-dimensional modeling and analysis of a high energy density Kelvin-Helmholtz experiment , 2012 .

[7]  R. P. Drake,et al.  Experimental observations of turbulent mixing due to Kelvin–Helmholtz instability on the OMEGA Laser Facility , 2012 .

[8]  B. Thompson,et al.  SDO/AIA OBSERVATION OF KELVIN–HELMHOLTZ INSTABILITY IN THE SOLAR CORONA , 2010, 1101.4249.

[9]  R. P. Drake,et al.  Using wall shocks to measure preheat in laser-irradiated, high-energy-density, hydrodynamics experiments , 2010 .

[10]  R. P. Drake,et al.  Wall shocks in high-energy-density shock tube experiments , 2009 .

[11]  R. S. Gillespie,et al.  Observation of a Kelvin-helmholtz instability in a high-energy-density plasma on the omega laser. , 2009, Physical review letters.

[12]  R. P. Drake,et al.  A high energy density shock driven Kelvin―Helmholtz shear layer experiment , 2008 .

[13]  O. Hurricane Design for a high energy density Kelvin–Helmholtz experiment , 2007 .

[14]  N. Lanier,et al.  Characterization and cross calibration of Agfa D4, D7, and D8 and Kodak SR45 x-ray films against direct exposure film at 4.0-5.5 keV , 2006 .

[15]  U. Alon,et al.  Vortex-merger statistical-mechanics model for the late time self-similar evolution of the Kelvin–Helmholtz instability , 2003 .

[16]  J. Jacobs,et al.  Experimental study of the Richtmyer–Meshkov instability of incompressible fluids , 2003, Journal of Fluid Mechanics.

[17]  P. Dimotakis The mixing transition in turbulent flows , 2000, Journal of Fluid Mechanics.

[18]  M. Begelman A Model for the Moving “Wisps” in the Crab Nebula , 1998, astro-ph/9809293.

[19]  Samuel A. Letzring,et al.  Upgrade of the OMEGA laser system , 1992, Photonics West - Lasers and Applications in Science and Engineering.

[20]  J. Boris,et al.  Rayleigh-Taylor and Kelvin-Helmholtz instabilities in targets accelerated by laser ablation , 1982 .

[21]  G. M. Corcos,et al.  Vorticity concentration and the dynamics of unstable free shear layers , 1976, Journal of Fluid Mechanics.

[22]  A. Roshko,et al.  On density effects and large structure in turbulent mixing layers , 1974, Journal of Fluid Mechanics.

[23]  R. D. Richtmyer Taylor instability in shock acceleration of compressible fluids , 1960 .

[24]  G. Taylor The instability of liquid surfaces when accelerated in a direction perpendicular to their planes. I , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[25]  Stephen M. Lane,et al.  HYADES—A plasma hydrodynamics code for dense plasma studies , 1994 .

[26]  E. Meshkov Instability of the interface of two gases accelerated by a shock wave , 1969 .