Differentially heated turbulent channel flow two-point correlations

TL;DR

This paper investigates how temperature differences affect turbulence structures in a heated channel flow using DNS, revealing significant asymmetries in heat transfer and turbulence near hot and cold walls at Re_tau=400.

Contribution

It provides detailed two-point correlation analysis of turbulence in differentially heated channel flow with variable properties, a novel focus in DNS studies.

Findings

Increased heat transfer at the hot wall.

Higher turbulence production at the cold wall.

Asymmetrical turbulence structures due to temperature gradient.

Abstract

This study analyzes the behavior of a differentially heated channel flow by means of a direct numerical simulations (DNS) with variable thermophysical properties under low-speed conditions focusing on the impact of the temperature gradient on the turbulence structures near the channel walls. The simulations were conducted at a mean friction Reynolds number of Re{\tau}m = 400 with a temperature ratio between the walls of Thot/Tcold = 2. Results show significant differences between the hot and cold walls that lead to an increased heat transfer at the hot wall and a higher turbulent production in the cold wall.