Crossover between two- and three-dimensional turbulence in spatial mixing layers
2014 (English)In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 745, 164-179 p.Article in journal (Refereed) Published
We investigate how the domain depth affects the turbulent behaviour in spatially developing mixing layers by means of large-eddy simulations based on a spectral vanishing viscosity technique. Analyses of spectra of the vertical velocity, of Lumley's diagrams, of the turbulent kinetic energy and of the vortex stretching show that a two-dimensional behaviour of the turbulence is promoted in spatial mixing layers by constricting the fluid motion in one direction. This finding is in agreement with previous works on turbulent systems constrained by a geometric anisotropy, pioneered by Smith, Chasnov & Waleffe (Phys. Rev. Lett., vol. 77, 1996, pp. 2467-2470). We observe that the growth of the momentum thickness along the streamwise direction is damped in a confined domain. An almost fully two-dimensional turbulent behaviour is observed when the momentum thickness is of the same order of magnitude as the confining scale.
Place, publisher, year, edition, pages
2014. Vol. 745, 164-179 p.
shear layer turbulence, shear layers, turbulent flows
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-145088DOI: 10.1017/jfm.2014.85ISI: 000333907700008OAI: oai:DiVA.org:kth-145088DiVA: diva2:716196
QC 201405082014-05-082014-05-082014-05-08Bibliographically approved