Direct numerical simulations are performed to predict the three-dimensional unsteady flow interactions in the near-field of a square jet issuing normal to a cross-flow. The simulated flow features reveal the formation of an upstream horseshoe vortex system, which is the result of an interaction between the oncoming channel floor shear layer and the transverse jet; the growth of a sequence of Ke...

Vortices have long been speculated to play a role in planet formation, via the collection of dust pressure maxima that arise at cores vortices protoplanetary discs. The question remains however: as collects core vortex, when does vortex remain stable and able collect further dust, why it break up? We study this by running high resolution 2D simulations laden vortices. By using terminal velocity...

Particle Image Velocimetry (PIV) is used to investigate the three-dimensional wakes of rigid pitching panels with a trapezoidal geometry, chosen to model idealized fish caudal fins. Experiments are performed for Strouhal numbers from 0.17 to 0.56 for two different trailing edge pitching amplitudes. A Lagrangian Coherent Structure (LCS) analysis is employed to investigate the formation and evolu...

The flow in the gap between an inner rotating cylinder concentric with an outer stationary cylinder with an imposed pressure-driven axial flow was studied experimentally using particle image velocimetry ~PIV! in a meridional plane of the annulus. The radius ratio was h50.83 and the aspect ratio was G547. Velocity vector fields for nonwavy toroidal and helical vortices show the axial flow windin...

The three-dimensionality of the velocity field in the wake of a circular cylinder has excited considerable interest and debate over the past decade. Presented here are experimental results that characterize the underlying vorticity field of such wakes. Using particle image velocimetry (PIV), instantaneous velocity fields were measured and from these the vorticity of the longitudinal vortices ly...

The eddy heat flux generated by the statistically equilibrated baroclinic instability of a uniform, horizontal temperature gradient is studied using a two-mode f-plane quasigeostrophic model. An overview of the dependence of the eddy diffusivity D on the bottom friction , the deformation radius , the vertical variation of the large-scale flow U, and the domain size L is provided by numerical si...

Given a stable configuration of point vortices for steady two-dimensional inviscid, incompressible fluid flow in a domain D, it is shown that there is another stable configuration of stationary vortices in D with vortices near the original vortices plus additional vortices near any points on the boundary where the speed of the original flow is a nonzero relative minimum.