Effects of rapid spanwise rotation on turbulent channel flow with a passive scalar

Brethouwer G, Schlatter P, Johansson AV (2011)

Publication Type: Conference contribution

Publication year: 2011

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

Book Volume: 2011-July

Conference Proceedings Title: 7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011

Event location: Ottawa, ON, CAN

Abstract

Direct numerical simulations of fully developed turbulent channel flow including a passive scalar rotating about the spanwise axis have been performed. The mean bulk Reynolds number, Reb = Ubh/ν ≥ 20000, where Ub is the bulk mean velocity and h the channel half width, is higher than in previous simulations and the rotation rate covers a wide range. At moderate rotation rates, turbulence on the stable channel side is significantly less damped than in DNS at lower Reb. At high rotation rates we observe re-occurring, quasi-periodic instabilities on the stable channel side. Between these events the turbulence is weak, but during the instability events the wall shear stress and turbulence intensity are much stronger. The instabilities are caused by structures resembling Tollmien-Schlichting (TS) waves that at some instant rapidly grow, then become unstable and finally break down into intense turbulence. After some time the TS waves form again and the process repeats itself in a periodic-like manner. Mean scalar profiles are also strongly affected by rotation and large scalar fluctuations are found on the border of the stable and unstable channel side. The turbulent Prandtl/Schmidt number of the scalar is much less than unity if there is rotation. Predicting scalar transport in rotating channel flow will therefore pose a challenge to turbulence models.

Authors with CRIS profile

Philipp Schlatter

Involved external institutions

Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) SE Sweden (SE)

How to cite

APA:

Brethouwer, G., Schlatter, P., & Johansson, A.V. (2011). Effects of rapid spanwise rotation on turbulent channel flow with a passive scalar. In 7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011. Ottawa, ON, CAN: International Symposium on Turbulence and Shear Flow Phenomena, TSFP.

MLA:

Brethouwer, Geert, Philipp Schlatter, and Arne V. Johansson. "Effects of rapid spanwise rotation on turbulent channel flow with a passive scalar." Proceedings of the 7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011, Ottawa, ON, CAN International Symposium on Turbulence and Shear Flow Phenomena, TSFP, 2011.

BibTeX: Download