A vorticity stretching diagnostic for turbulent flows
Malm J, Schlatter P, Sandham ND (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
Vorticity stretching in wall-bounded turbulent and transitional flows has been investigated by means of a new diagnostic, designed to pick up regions with large amounts of vorticity stretching. It was found that the largest occurrence of vorticity stretching in fully turbulent channel flows is present at a wall-normal distance of y+ = 6.5, i.e. in the transition between the viscous sublayer and the buffer region. Instantaneous data showed that the coherent structures associated with these stretching events have the shape of flat ‘pancake structures’ in the vicinity of high-speed streaks, here denoted ‘h-type’ events. The other event found, also studied in an asymptotic suction boundary layer, is the ‘l-type’ event present on top of an unstable low-speed streak. These events are further thought to be associated with the exponential growth of streamwise vorticity in the turbulent near-wall cycle.
Authors with CRIS profile
Involved external institutions
Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH)
Sweden (SE)
University of Southampton
United Kingdom (GB)
Sweden (SE)
University of Southampton
United Kingdom (GB)
How to cite
APA:
Malm, J., Schlatter, P., & Sandham, N.D. (2011). A vorticity stretching diagnostic for turbulent flows. 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:
Malm, Johan, Philipp Schlatter, and Neil D. Sandham. "A vorticity stretching diagnostic for turbulent flows." 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.
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