A multi-fidelity approach to sensitivity estimation in large eddy simulation
ORAL
Abstract
An approach to compute approximate sensitivities in a large eddy simulation (LES) is proposed and assessed. The method is based on solving a linearized
mean equation, where the mean equation is defined based on the LES solution. This requires closure modeling which makes the computed sensitivities
approximate; the closure modeling is based on computing the inferred eddy viscosity from the LES data. The method is assessed for the flow over a
NACA0012 airfoil at different angles of attack, with the Reynolds number as the varying parameter and the lift and drag coefficients as the quantities-
of-interest. The results show the importance of accurate closure modeling, specifically that treating the eddy viscosity as “frozen” is insufficiently accurate.
mean equation, where the mean equation is defined based on the LES solution. This requires closure modeling which makes the computed sensitivities
approximate; the closure modeling is based on computing the inferred eddy viscosity from the LES data. The method is assessed for the flow over a
NACA0012 airfoil at different angles of attack, with the Reynolds number as the varying parameter and the lift and drag coefficients as the quantities-
of-interest. The results show the importance of accurate closure modeling, specifically that treating the eddy viscosity as “frozen” is insufficiently accurate.
*This work is supported by the Dept of Energy PSAAP-3 program (grant DE-NA0003993)The authors would like to thank Deepthought2 at UMD and the CZ clusters at LLNL for the computational resources.
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Presenters
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Walter Arias-Ramirez
- University of Maryland, College Park