Simulation of a Large-Eddy-Break-up Device (LEBU) in a Moderate Reynolds Number Turbulent Boundary Layer

Chin C, Orlu R, Monty J, Hutchins N, Ooi A, Schlatter P (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Flow Turbulence and Combustion Springer Verlag (Germany)

Book Volume: 98

Pages Range: 445-460

Journal Issue: 2

DOI: 10.1007/s10494-016-9757-y

Abstract

A well-resolved large eddy simulation (LES) of a large-eddy break-up (LEBU) device in a spatially evolving turbulent boundary layer is performed with, Reynolds number, based on free-stream velocity and momentum-loss thickness, of Reθ ≈ 4300. The implementation of the LEBU is via an immersed boundary method. The LEBU is positioned at a wall-normal distance of 0.8 δ (δ denoting the local boundary layer thickness at the location of the LEBU) from the wall. The LEBU acts to delay the growth of the turbulent boundary layer and produces global skin friction reduction beyond 180δ downstream of the LEBU, with a peak local skin friction reduction of approximately 12 %. However, no net drag reduction is found when accounting for the device drag of the LEBU in accordance with the towing tank experiments by Sahlin et al. (Phys. Fluids 31, 2814, 1988). Further investigation is performed on the interactions of high and low momentum bulges with the LEBU and the corresponding output is analysed, showing a ‘break-up’ of these large momentum bulges downstream of the LEBU. In addition, results from the spanwise energy spectra show consistent reduction in energy at spanwise length scales for λz+>1000 independent of streamwise and wall-normal location when compared to the corresponding turbulent boundary layer without LEBU.

Authors with CRIS profile

Philipp Schlatter

Involved external institutions

The University of Melbourne

Australia (AU) Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH)

Sweden (SE)

How to cite

APA:

Chin, C., Orlu, R., Monty, J., Hutchins, N., Ooi, A., & Schlatter, P. (2017). Simulation of a Large-Eddy-Break-up Device (LEBU) in a Moderate Reynolds Number Turbulent Boundary Layer. Flow Turbulence and Combustion, 98(2), 445-460. https://doi.org/10.1007/s10494-016-9757-y

MLA:

Chin, Cheng, et al. "Simulation of a Large-Eddy-Break-up Device (LEBU) in a Moderate Reynolds Number Turbulent Boundary Layer." Flow Turbulence and Combustion 98.2 (2017): 445-460.

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