A synthetic jet is one of flow control devices that can topologically disturb surrounding flow field by adding periodic injection and suction of surrounding fluid using an oscillating membrane through an orifice. This device can be applied to the downsized fluid machinery without a net mass injection of fluid for the simplified structure. In this study, the phase-averaged three-dimensional flow...

Vortex interactions in helicopter rotor wakes are visualized using enhanced flow visualization techniques, which in turn play a crucial role in understanding the dynamics of these complex flows. Iso-surfaces are clipped in a 3D volume to reduce visual clutter. Flow textures are improved to highlight vortical flow structure and vortex-wake interactions. These visualization techniques are applied...

Large-eddy simulations of pairs of artificially generated longitudinal vortices embedded in a two-dimensional turbulent boundary layer are performed to study the dynamics of the vortical structures and to provide the unsteady inflow data for use in a future turbomachinery simulation. An immersed boundarymethod is employed to represent the wall-mounted half-delta wings that generate the counter-...

a large eddy, or vortex, that spins within the sinus cavity. The fluid motion within similar recirculating flows is known to be unstable with an early transition to turbulence. The stability of the aortic sinus vortex was examined in the current study in an in vitro pulsatile flow rig. The geometry of the experimental test section was the same as the geometry of the natural aortic root. Differe...

PURPOSE To present and validate a new method for 4D flow quantification of vortex-ring mixing during early, rapid filling of the left ventricle (LV) as a potential index of diastolic dysfunction and heart failure. MATERIALS AND METHODS 4D flow mixing measurements were validated using planar laser-induced fluorescence (PLIF) in a phantom setup. Controls (n = 23) and heart failure patients (n =...

The technical relevance of swirling flows has inspired numerous investigations into the field: swirling flow burners, trailing vortices of delta wings, separators etc. are some of the applications where such research has yielded interesting results. At the same time, geophysics-inspired general swirling flow studies provided much input to this field. A subcategory of swirling flows is that wher...

In this paper, the oscillating two-dimensional laminar flow about a cylinder and the oscillation of a cylinder in still water are studied. A finite volume method is applied to solve the Navier Stokes equations using SIMPLEC algorithm on a body fitted co-located O-type grid. In this study, the non-dimensional flow numbers, Keulegan-Carpenter and Stokes’ numbers are chosen over a range where diff...

The thin-layer Navier-Stokes equations are solved for two complete missile configurations on an IBM 3090-200 vectro-facility supercomputer. The conservation form of the three-dimensional equations, written in generalized coordinates, are finite differenced and solved on a body-fitted curvilinear grid system developed in conjunction with the flowfield solver. The numerical procedure is based on ...

We study the observability of one and two point vortex flow from one or two Eulerian or Lagrangian observations. By observability we mean the ability to determine the locations and strengths of the vortices from the time history of the observations. An Eulerian observation is a measurement of the velocity of the flow at a fixed point in the domain of the flow. A Lagrangian observation is the me...

Three devices for treating contaminated water using a cavitating vortex have been developed and tested. The first device uses stationary twin volute casings to generate cavitating vortices. Observation of the collisions among the opposing counter-rotating vortices revealed that their end portions whirl, that the vortices never collide head-on, and that they eventually separate into several smal...