A comparison of meso-scaled heat flux and temperature in fully-developed turbulent pipe and channel flows

Abstract

Data from direct numerical simulations (DNS) of constant surface heat-flux in fully-developed turbulent pipe and channel flows is used to explore the physical mechanisms of turbulent heat transfer. The analysis employs a theory based on the magnitude ordering of terms in the mean thermal energy equation of wall-bounded turbulent heat transfer, Wei et al. [10]. Identifying the leading order terms in the mean energy equation reveals a four layer structure similar to that found for the mean momentum equation. The traditional inner scale is then transformed into new inner length and then the invariant form admitted by the relevant form of the mean energy equation is determined. These apply to in..