Hydrodynamic simulations of rippled shock wave driven by laser ablation and initial pressure discontinuity

POSTER

Abstract

When lasers irradiate a target with a rippled surface, the ablation pressure launches a rippled shock induced by the initial target surface. We study the evolution of a rippled shock driven by an ablation surface and the associated flow field using inviscid hydrodynamic simulations in FLASH. For strong shocks (O(100 GPa)), the shock separates from the ablation surface at very long times. Hence, the reverberations of pressure waves in the region between the shock front and the ablation surface can interact and modify the rippled shock evolution. We compare the evolution of the decaying amplitude of a rippled shock driven by: 1) laser-driven ablation and 2) initial pressure discontinuity across an interface separated by two media. First, we match the zeroth order flow profiles in the shock-compressed region in both the cases by driving a steady planar shock of equal strength. Next, we conduct simulations on sinusoidally-perturbed target surface (interface) of multiple wavelengths. Finally, we analyze the effect of including dynamic viscosity and compare our results with previous theoretical models of Miller et al. (1991) and Ishizaki et al. (1996).

*This work was performed under the auspices of the U.S. Department of Energy under Grant DESC0019329 within the joint HEDLP program.

Presenters

  • Nitish Acharya

    • Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA
    • University of Rochester

Authors

  • Nitish Acharya

    • Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA
    • University of Rochester

  • Danae Polsin

    • Laboratory for Laser Energetics
    • Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA. Laboratory for Laser Energetics, Rochester, NY, USA.

  • Hussein Aluie

    • Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA. Laboratory for Laser Energetics, Rochester, NY, USA.
    • University of Rochester

  • Gilbert W Collins

    • University of Rochester
    • Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA. Laboratory for Laser Energetics, Rochester, NY, USA. Department of Physics and Astronomy,

  • Ryan Rygg

    • University of Rochester

  • Peter M Celliers

    • Lawrence Livermore Natl Lab

  • Jessica Shang

    • University of Rochester