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arXiv · 2605.13671

Stochastic modeling of Fourier modes in two-dimensional turbulence via filtered white noise

Paolo Cifani·Franco Flandoli·Andrea Zanoni
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Abstract

Modeling turbulent flows by a random Fourier decomposition is a classical procedure in order to use simplified models of turbulence in heat transport and other applications. We investigate the Fourier time series of two-dimensional Navier-Stokes equations with friction and damping, forced at intermediate scales, and identify significant statistical structures. In particular, we find the existence of a typical time correlation length, and propose a stochastic model for the Fourier components. Finally, we compute the transport of a passive scalar under advection-diffusion dynamics by means of direct numerical simulation of the stochastic damped Navier-Stokes equation and compare it with analytical predictions of the effective diffusion produced by the stochastic model.

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Paolo Cifani, Franco Flandoli, Andrea Zanoni. 2026-05-13. Stochastic modeling of Fourier modes in two-dimensional turbulence via filtered white noise. https://arxiv.org/abs/2605.13671

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