Journal article

Direct numerical simulation of high aspect ratio spanwise-aligned bars

M MacDonald, A Ooi, R Garcia-Mayoral, N Hutchins, D Chung

Journal of Fluid Mechanics | Cambridge University Press (CUP) | Published : 2018

Abstract

We conduct minimal-channel direct numerical simulations of turbulent flow over two-dimensional rectangular bars aligned in the spanwise direction. This roughness has often been described as d -type, as the roughness function ΔU+ is thought to depend only on the outer-layer length scale (pipe diameter, channel half-height or boundary layer thickness). This is in contrast to conventional engineering rough surfaces, named k -type, for which ΔU+ depends on the roughness height, k. The minimal-span rough-wall channel is used to circumvent the high cost of simulating high Reynolds number flows, enabling a range of bars with varying aspect ratios to be investigated. The present results show that in..

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Grants

Funding Acknowledgements

The authors would like to gratefully acknowledge the financial support of the Australian Research Council and the Bushfire and Natural Hazards Cooperative Research Council. M.M. was supported through an Australian Government Research Training Program Scholarship. Computational time was granted under the Victoria Life Sciences Computational Initiative, which is supported by the Victorian Government, Australia and the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia.