The skin-friction coefficient of a turbulent boundary layer modified by a large-eddy break-up device
Chan IC, Orlu R, Schlatter P, Chin RC (2021)
Publication Type: Journal article
Publication year: 2021
Journal
Book Volume: 33
Article Number: 035153
Journal Issue: 3
DOI: 10.1063/5.0043984
Abstract
A computational study based on well-resolved large-eddy simulations is performed to study the skin friction modification by a large-eddy breakup device (LEBU) in a zero-pressure-gradient turbulent boundary layer. The LEBU was modeled using an immersed boundary method. It is observed that the presence of the device leads to the generation of wake vortices, which propagate downstream from the LEBU and toward the wall. A skin friction decomposition procedure is utilized to study different physical mechanisms of the observed skin friction reduction. From the skin friction decomposition, it is found that the skin friction reduction can be characterized by three universal regions of different changes for the skin friction contributions. The first region is predominantly associated with the formation of the wake vortices and the reduction of Reynolds shear stress. In the second region, the mean streamwise velocity fields show that a region of velocity deficit formed downstream of the LEBU propagates toward the wall and leads to turbulence reduction due to wake wall interactions, which also induces a local maximum skin friction reduction. In the third region, the dissipation of wake vortices leads to the regeneration of Reynolds shear stress. A quadrant analysis of the Reynolds shear stress contribution reveals that the LEBU increases the Q2 and Q4 contributions and attenuates the Q1 and Q3 contributions in the first region, followed by an onset of Reynolds shear stress further downstream.
Authors with CRIS profile
Involved external institutions
University of Adelaide
Australia (AU)
Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH)
Sweden (SE)
Australia (AU)
Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH)
Sweden (SE)
How to cite
APA:
Chan, I.C., Orlu, R., Schlatter, P., & Chin, R.C. (2021). The skin-friction coefficient of a turbulent boundary layer modified by a large-eddy break-up device. Physics of Fluids, 33(3). https://doi.org/10.1063/5.0043984
MLA:
Chan, I. C., et al. "The skin-friction coefficient of a turbulent boundary layer modified by a large-eddy break-up device." Physics of Fluids 33.3 (2021).
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