Turbulent heat transfer in a channel flow at transitional Reynolds numbers
Abstract
Direct numerical simulation of a turbulent channel flow with heat transfer was performed at very low Reynolds numbers. Two different thermal boundary conditions were studied, and temperature was considered as a passive scalar. The computations were carried out with huge computational boxes (up to 327.7 x 2 x 128 in the streamwise, wall-normal, and spanwise directions, respectively). The emphases of this paper are to investigate the large-scale structure (puff) in the intermittent-turbulent flow including the scalar fields and to provide the values of the transitional and critical Reynolds numbers, below which the turbulent flow becomes intermittent and laminar, respectively. The statistics, such as the skin friction and the Stanton number, were also examined: they suggest that the puff should be effective in sustaining turbulence and in heat transfer enhancement.
Keywords
Cite
@article{arxiv.1406.0959,
title = {Turbulent heat transfer in a channel flow at transitional Reynolds numbers},
author = {Takahiro Tsukahara and Hiroshi Kawamura},
journal= {arXiv preprint arXiv:1406.0959},
year = {2014}
}
Comments
10 pages, 7 figures: A revised and expanded version of a paper that was presented with the same title by T. Tsukahara and H. Kawamura, at 1st Asian Symposium on Computational Heat Transfer and Fluid Flow, 18-21 October 2007, Xi'an, China