Experimental adventures in variable-density mixing

Journal Article · 20 November 2018 · Physical Review Fluids

DOI: https://doi.org/10.1103/PhysRevFluids.3.110501 · OSTI ID:1484653

Prestridge, Kathy ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Variable-density mixing occurs in the ocean and atmosphere, inertial confinement fusion capsules, stars, and many industrial processes. Our team studies mixing at the laboratory scale, with the goal of extending our understanding to larger and smaller length scales and into multiphysics regimes that include such physics as chemical and thermonuclear reactions and high energy density plasmas. I will provide examples of studies from Los Alamos in variable-density mixing in multiple regimes, including shock-driven mixing, subsonic mixing, and high energy density (HED) plasma mixing. In all cases, the density differences of the mixing fluids are at least double, making the mixing well outside regimes covered by the Boussinesq approximation. In these flows, we have discovered time-dependent mixing phenomena, asymmetries in mixing and distribution of turbulent kinetic energy, and interscale energy transfer driven by the mean ow that moves energy from small to large scales via eddy stretching. We have improved our physical understanding by implementing diagnostics such as particle image velocimetry and planar laser induced fluorescence in challenging, shock-driven ow regimes. Our experimental studies and physical understanding benefit from collaborations with colleagues studying turbulence modeling and performing validation simulations, and these collaborations push us to further improve our experimental platforms and diagnostics.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA). Office of Defense Programs (DP) (NA-10)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1484653
• Report Number(s): LA-UR-18-24860
• Journal Information: Physical Review Fluids, Journal Name: Physical Review Fluids Journal Issue: 11 Vol. 3; ISSN 2469-990X
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English