Uncertainty quantification for turbulent mixing simulations

Journal Article · Thu Jan 20 04:00:00 EST 2011

OSTI ID:1048801

Sharp, David Howland ^[1]; Glimm, James G ^[2]; Kaman, Tulin ^[2]

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1. Los Alamos National Laboratory
2. STONEY BROOK UNIV.

We have achieved validation in the form of simulation-experiment agreement for Rayleigh-Taylor turbulent mixing rates (known as {alpha}) over the past decade. The problem was first posed sixty years ago. Recent improvements in our simulation technology allow sufficient precision to distinguish between mixing rates for different experiments. We explain the sensitivity and non-universality of the mixing rate. These playa role in the difficulties experienced by many others in efforts to compare experiment with simulation. We analyze the role of initial conditions, which were not recorded for the classical experiments of Youngs et al. Reconstructed initial conditions with error bars are given. The time evolution of the long and short wave length portions of the instability are analyzed. We show that long wave length perturbations are strong at t = 0, but are quickly overcome by the rapidly growing short wave length perturbations. These conclusions, based solely on experimental data analysis, are in agreement with results from theoretical bubble merger models and numerical simulation studies but disagree with models based on superposition of modes.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1048801
• Report Number(s): LA-UR-11-00422; LA-UR-11-422
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACCURACY
BUBBLES
INSTABILITY
SENSITIVITY
SIMULATION
VALIDATION