Journal article

A systematic investigation of roughness height and wavelength in turbulent pipe flow in the transitionally rough regime

L Chan, M MacDonald, D Chung, N Hutchins, A Ooi

JOURNAL OF FLUID MECHANICS | CAMBRIDGE UNIV PRESS | Published : 2015

Abstract

Direct numerical simulations (DNS) are conducted for turbulent flow through pipes with three-dimensional sinusoidal roughnesses explicitly represented by body-conforming grids. The same viscous-scaled roughness geometry is first simulated at a range of different Reynolds numbers to investigate the effects of low Reynolds numbers and low R0/h, where R0 is the pipe radius and h is the roughness height. Results for the present class of surfaces show that the Hama roughness function ΔU+ is only marginally affected by low Reynolds numbers (or low R0/h), and observations of outer-layer similarity (or lack thereof) show no signs of sensitivity to Reynolds number. Then, building on this, a systemati..

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Grants

Funding Acknowledgements

The authors would like to gratefully thank the Australian Research Council for the financial support and the Victorian Life Science Computational Institute (VLSCI) for providing the computational time.