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Now showing items 21-27 of 27
Designing a more nonlinearly stable laminar flow via boundary manipulation
(Cambridge University PressJournal of Fluid Mechanics, 2013-12-04)
We show how a fully nonlinear variational method can be used to design a more nonlinearly stable laminar shear flow by quantifying the effect of manipulating the boundary conditions of the flow. Using the example of plane ...
Turbulent mixing due to the Holmboe wave instability at high Reynolds number
(Cambridge University PressJournal of Fluid Mechanics, 2016)
We consider numerically the transition to turbulence and associated mixing in stratified shear flows with initial velocity distribution $\bar U$(z, 0)e$_{x}$ = U$_{0}$e$_{x}$ tanh(z/d) and initial density distribution $\bar ...
Coherent structures in interacting vortex rings
(American Physical SocietyPhysical Review Fluids, 2017-02-21)
We investigate experimentally the nonlinear structures that develop from interacting vortex rings induced by a sinusoidally oscillating ellipsoidal disk in fluid at rest. We vary the scaled amplitude or Keulegan-Carpenter ...
Irreversible mixing by unstable periodic orbits in buoyancy dominated stratified turbulence
(Cambridge University PressJournal of Fluid Mechanics, 2017-10-26)
We consider turbulence driven by a large-scale horizontal shear in Kolmogorov flow
(i.e. with sinusoidal body forcing) and a background linear stable strati cation with buoyancy frequency $N^2_B$ imposed in the third, ...
Layer formation in horizontally forced stratified turbulence: Connecting exact coherent structures to linear instabilities
(Journal of Fluid Mechanics, 2017-12-10)
© 2017 Cambridge University Press. We consider turbulence in a stratified 'Kolmogorov' flow, driven by horizontal shear in the form of sinusoidal body forcing in the presence of an imposed background linear stable ...
Horizontal locomotion of a vertically flapping oblate spheroid
(Cambridge University PressJournal of Fluid Mechanics, 2018-04-10)
We consider the self-induced motions of three-dimensional oblate spheroids of density $\rho_s$ with varying aspect ratios $AR=b/c \leq 1$, where $b$ and $c$ are the spheroids' centre-pole radius and centre-equator radius ...