TY - JOUR
T1 - A performance analysis of ensemble averaging for high fidelity turbulence simulations at the strong scaling limit
AU - Makarashvili, Vakhtang
AU - Merzari, Elia
AU - Obabko, Aleksandr
AU - Siegel, Andrew
AU - Fischer, Paul
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/10
Y1 - 2017/10
N2 - We analyze the potential performance benefits of estimating expected quantities in large eddy simulations of turbulent flows using true ensembles rather than ergodic time averaging. Multiple realizations of the same flow are simulated in parallel, using slightly perturbed initial conditions to create unique instantaneous evolutions of the flow field. Each realization is then used to calculate statistical quantities. Provided each instance is sufficiently de-correlated, this approach potentially allows considerable reduction in the time to solution beyond the strong scaling limit for a given accuracy. This paper focuses on the theory and implementation of the methodology in Nek5000, a massively parallel open-source spectral element code.
AB - We analyze the potential performance benefits of estimating expected quantities in large eddy simulations of turbulent flows using true ensembles rather than ergodic time averaging. Multiple realizations of the same flow are simulated in parallel, using slightly perturbed initial conditions to create unique instantaneous evolutions of the flow field. Each realization is then used to calculate statistical quantities. Provided each instance is sufficiently de-correlated, this approach potentially allows considerable reduction in the time to solution beyond the strong scaling limit for a given accuracy. This paper focuses on the theory and implementation of the methodology in Nek5000, a massively parallel open-source spectral element code.
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U2 - 10.1016/j.cpc.2017.05.023
DO - 10.1016/j.cpc.2017.05.023
M3 - Article
AN - SCOPUS:85023771083
SN - 0010-4655
VL - 219
SP - 236
EP - 245
JO - Computer Physics Communications
JF - Computer Physics Communications
ER -