2022/10/17 by Gregory L. Eyink, Eyink, Gregory, Amir Homayoun Jafari +1 · 2 citations
Physics and Astronomy · Engineering · Materials Science · #Advanced Thermodynamics and Statistical Mechanics #Fluid Dynamics and Turbulent Flows #Material Dynamics and Properties
paper · pdf · doi:10.48550/arxiv.2210.08671
We discuss application of methods from the Kraichnan model of turbulent advection to the study of non-equilibrium concentration fluctuations arising during diffusion in liquid mixtures at high Schmidt numbers. This approach treats nonlinear advection of concentration fluctuations exactly, without linearization. Remarkably, we find that static and dynamic structure functions obtained by this method reproduce precisely the predictions of linearized fluctuating hydrodynamics. It is argued that this agreement is an analogue of anomaly non-renormalization which does not, however, protect higher-order multi-point correlations. The latter should thus yield non-vanishing cumulants, unlike those for the Gaussian concentration fluctuations predicted by linearized theory.