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DOE OSTI · 2491431

Determining Exact RANS Operators with the Macroscopic Forcing Method (Final Report)

Lavacot, D. L. O.-L. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Stanford Univ., CA (United States)]·Liu, J. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Williams, H. [Stanford Univ., CA (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Morgan, B. E. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Mani, A. [Stanford Univ., CA (United States)]
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Abstract

This report contains a compilation of key results and findings from the ACT project “Determining Exact RANS Operators with the Macroscopic Forcing Method.” The Macroscopic Forcing Method (MFM), a numerical tool for determining closure operators, is used to measure eddy diffusivity moments in Rayleigh-Taylor (RT) instability. It is first applied to low-Atwood 2D RT instability; that work is then extended to 3D RT at different finite Atwood numbers. It is found that nonlocality is important for modeling the mean scalar transport closure operator in RT mixing. Additionally, work is done to improve the statistical convergence of MFM for chaotic problems like RT mixing.

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Lavacot, D. L. O.-L. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Stanford Univ., CA (United States)], Liu, J. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Williams, H. [Stanford Univ., CA (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Morgan, B. E. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Mani, A. [Stanford Univ., CA (United States)]. 2024-12-01. Determining Exact RANS Operators with the Macroscopic Forcing Method (Final Report). https://doi.org/10.2172/2491431

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