Towards lowering dissipation bounds for turbulent flows
Fachbereich Physik der Philipps-Universität, Renthof 6, 35032 Marburg, Germany
Published online: 15 July 1999
We examine the background flow variational principle for calculating bounds on the energy dissipation rate in turbulent shear flow, and suggest to select this principle's test functions such that they comply with the small-scale smoothness of real turbulent velocity fields. A self-consistent algorithm implementing this requirement then yields an upper bound on the dimensionless dissipation coefficient which shows a weak power-law decrease at high Reynolds numbers, instead of approaching a nonzero constant, as it did in previous estimates.
PACS: 47.27.Nz – Boundary layer and shear turbulence / 47.27.Jv – High-Reynolds-number turbulence / 47.20.Ft – Instability of shear flows
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999