We report a possible occurrence of horizontal roll vortices over the Adriatic Sea during the bora wind. The National Center for Atmospheric Research Electra aircraft measured the turbulence structure above the Adriatic on 07 November 1999 during the Mesoscale Alpine Program. The data indicate that horizontal roll vortices are generated by the strong cold-air outbreak associated with bora. The r...

In this paper, the lateral line trunk canal (LLTC) of a fish is modeled to investigate how it is affected by an external flow field. Potential flow theory is adopted to model the flow field around a fish's body in the presence of a Karman vortex street. Karman and reverse Karman streets represent the flow patterns behind a bluff body and a traveling fish, respectively. An analytical solution is...

The slender body theory, lifting surface theories, and more recently panel methods and Navier-Stokes solvers have been used to study the hydrodynamics of fish swimming. This paper presents progress on swimming hydrodynamics using a boundary integral equation method (or boundary element method) based on potential flow model. The unsteady three-dimensional BEM code 3DynaFS that we developed and u...

Studies of flow behind a single cylinder have greatly contributed to our understanding of the development of complex flows like the Kármán vortex street[1] or turbulent flows. At the first instability in such a system the laminar flow (LF) becomes time dependent and vortices appear. It has been shown that this transition to the vortex shedding phase (VS) is well described by the supercritical H...

Research on the lateral line of fish has mainly focused on the detection of oscillating objects. Yet many fish are able to track vortex wakes that arise from other fish. It is not yet known what the sensory input from a wake looks like and how fish can extract relevant information from it. We present a mathematical model to determine how vortices stimulate the canal lateral line and verify it b...

A north-south flow pattern with a recurrence period approximately equal to the solar rotation period was observed by Voyager 2 during 1995 at 47 AU, nearly a solar cycle after the north-south flows were first observed near 21 AU during 1986. The north-south flow deflections observed during 1995 were less regular than those observed in 1986. One finds the same qualitative associations between th...

It is shown experimentally that free shear flows can be substantially altered through 134) > t direct control of the large coherent vortices present in the flow. First, flow-visualization experiments are conducted in Kalliroscope fluid at Reynolds number 550. A foil is placed in the wake of a D-section cylinder, sufficiently far behind 160" the cylinder so that it does not interfere with the vo...