Reduced Data-Driven Turbulence Closure for Capturing Long-Term Statistics

Fuente: arXiv
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Main Authors: Hoekstra, Rik, Crommelin, Daan, Edeling, Wouter
Format: Preprint
Published: 2024
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author Hoekstra, Rik
Crommelin, Daan
Edeling, Wouter
author_facet Hoekstra, Rik
Crommelin, Daan
Edeling, Wouter
contents We introduce a simple, stochastic, a-posteriori, turbulence closure model based on a reduced subgrid scale term. This subgrid scale term is tailor-made to capture the statistics of a small set of spatially-integrate quantities of interest (QoIs), with only one unresolved scalar time series per QoI. In contrast to other data-driven surrogates the dimension of the "learning problem" is reduced from an evolving field to one scalar time series per QoI. We use an a-posteriori, nudging approach to find the distribution of the scalar series over time. This approach has the advantage of taking the interaction between the solver and the surrogate into account. A stochastic surrogate parametrization is obtained by random sampling from the found distribution for the scalar time series. Compared to an a-priori trained convolutional neural network, evaluating the new method is computationally much cheaper and gives similar long-term statistics.
format Preprint
id arxiv_https___arxiv_org_abs_2407_14132
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Reduced Data-Driven Turbulence Closure for Capturing Long-Term Statistics
Hoekstra, Rik
Crommelin, Daan
Edeling, Wouter
Dynamical Systems
Numerical Analysis
We introduce a simple, stochastic, a-posteriori, turbulence closure model based on a reduced subgrid scale term. This subgrid scale term is tailor-made to capture the statistics of a small set of spatially-integrate quantities of interest (QoIs), with only one unresolved scalar time series per QoI. In contrast to other data-driven surrogates the dimension of the "learning problem" is reduced from an evolving field to one scalar time series per QoI. We use an a-posteriori, nudging approach to find the distribution of the scalar series over time. This approach has the advantage of taking the interaction between the solver and the surrogate into account. A stochastic surrogate parametrization is obtained by random sampling from the found distribution for the scalar time series. Compared to an a-priori trained convolutional neural network, evaluating the new method is computationally much cheaper and gives similar long-term statistics.
title Reduced Data-Driven Turbulence Closure for Capturing Long-Term Statistics
topic Dynamical Systems
Numerical Analysis
url https://arxiv.org/abs/2407.14132