Impact of corner geometry on the secondary flow in turbulent ducts

Vidal A, Vinuesa R, Schlatter P, Nagib HM (2017)

Publication Type: Conference contribution

Publication year: 2017

Publisher: International Symposium on Turbulence and Shear Flow Phenomena, TSFP10

Book Volume: 3

Conference Proceedings Title: 10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017

Event location: Chicago, IL, USA

ISBN: 9780000000002

Abstract

In the present study we perform direct numerical simulations (DNSs) of fully-developed turbulent square ducts with round corners at Reτ,c ∼ 180 and 360, and rectangular ducts of width-toheight ratios of 3 and 5 with rounded side walls at Reτ,c ∼ 180. The friction Reynolds number Reτ,c is based on the centerplane friction velocity and the half-height of the duct. The results are compared with the corresponding duct cases with 90° corners. We focus on the influence of the rounding on the mean cross-stream secondary flow and on further characterizing the mechanisms that produce it. Unexpectedly, the rounded ducts exhibit higher cross-flow rates and their secondary vortices relocate near the transition point between the straight and curved walls. This behavior is associated to the statistically preferential arrangement of sweeping events entering through the curved wall, which trigger an ejection on the adjacent straight wall. We have yet to find effective modifications to the corners or transverse ends of a rectangular duct that would render better rigorous modeling of two-dimensional channel flows.

Authors with CRIS profile

Philipp Schlatter

Involved external institutions

Illinois Institute of Technology US United States (USA) (US) Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) SE Sweden (SE)

How to cite

APA:

Vidal, A., Vinuesa, R., Schlatter, P., & Nagib, H.M. (2017). Impact of corner geometry on the secondary flow in turbulent ducts. In 10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017. Chicago, IL, USA: International Symposium on Turbulence and Shear Flow Phenomena, TSFP10.

MLA:

Vidal, Alvaro, et al. "Impact of corner geometry on the secondary flow in turbulent ducts." Proceedings of the 10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017, Chicago, IL, USA International Symposium on Turbulence and Shear Flow Phenomena, TSFP10, 2017.

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