Streamwise vortices and transition to turbulence

Autor:	James M. Hamilton, Frederick H. Abernathy
Rok vydání:	1994
Předmět:	Flow visualization Physics Turbulence Mechanical Engineering Mechanics Velocimetry Condensed Matter Physics Vortex shedding Critical value Vortex Physics::Fluid Dynamics Classical mechanics Mechanics of Materials Condensed Matter::Superconductivity Horseshoe vortex
Zdroj:	Journal of Fluid Mechanics. 264:185-212
ISSN:	1469-7645 0022-1120
DOI:	10.1017/s0022112094000637
Popis:	A series of experiments was conducted to determine the conditions under which streamwise vortices can cause transition to turbulence in shear flows. A specially designed obstacle was used to produce a single vortex in a water-table flow, and the design of this obstacle is discussed. Laser-Doppler velocimetry measurements of the streamwise and crossflow velocity fields were made in transitional and non-transitional flows, and flow visualization was also used. It was found that strong vortices (vortices with large circulation) lead to turbulence while weaker vortices do not. Determination of a critical value of vortex strength for transition, however, was complicated by ambiguities in calculating the vortex circulation. The profiles of streamwise velocity were found to be inflexional for both transitional and non-transitional flows. Transition in single-vortex and multi-vortex flows was compared, and no qualitative differences were observed, suggesting no significant vortex interactions affecting transition.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a507929640e421992023e297419e26c1 https://doi.org/10.1017/s0022112094000637 Zobrazit plný text záznamu