Eddy thermal diffusivity model and mean temperature profiles in turbulent vertical convection

TL;DR

This paper introduces a space-dependent eddy thermal diffusivity model for turbulent vertical convection, deriving analytical mean temperature profiles that align well with numerical simulations.

Contribution

The paper presents a novel space-dependent diffusivity model that analytically describes mean temperature profiles in turbulent vertical convection.

Findings

Mean temperature profiles follow two universal scaling functions.

Model parameters determine characteristic velocities in inner and outer regions.

Results agree well with direct numerical simulation data.

Abstract

In this paper, we propose a space-dependent eddy thermal diffusivity model for turbulent vertical natural convection in a fluid between two infinite vertical walls at different temperatures. Using this model, we derive analytical results for the mean temperature profile. Our results reveal that mean temperature profiles for different Rayleigh and Prandtl numbers are described by two universal scaling functions in the inner region next to the walls and the outer region near the centerline between the two walls and the characteristic temperature scales in the inner and outer regions are expressed in terms of the two parameters of the model which determine the characteristic velocities for heat transfer in the two regions. We show that these results are in good agreement with direct numerical simulation data.