It is shown experimentally that free shear flows can be substantially altered through direct control of the large coherent vortices present in the flow.

Thrust-producing harmonically oscillating foils are studied through force and power
measurements, as well as visualization data, to classify the principal characteristics of
the flow around and in the wake of the foil. Visualization data are obtained using
digital particle image…

Visualization studies of the flow behind an oscillating tapered cylinder are performed
at Reynolds numbers from 400 to 1500. The cylinder has taper ratio 40:1 and is
moving at constant forward speed U while being forced to oscillate harmonically
in…

Significant progress has been made in understanding
some of the basic mechanisms of force production and flow manipulation
in oscillating foils for underwater use. Biomimetic observations,
however, show that there is a lot more to be learned, since
many of…

Forces are measured at both ends of rigid cylinders with span 60 cm, performing
transverse oscillations within an oncoming stream of water, at Reynolds number
Re ~3800. Forced harmonic motions and free vibrations of uniform and tapered
cylinders are studied.…

We consider the nonlinear interaction problem of surface waves with a tethered
near-surface buoy. Our objective is to investigate mechanisms for nonlinear short
surface wave generation in this complete coupled wave-buoy-cable dynamical system.
We develop an effective numerical simulation capability…

We present experimental force and power measurements demonstrating that the power
required to propel an actively swimming, streamlined, fish-like body is significantly
smaller than the power needed to tow the body straight and rigid at the same speed
U. The…

The design and construction of a biomimetic flapping
foil autonomous underwater vehicle is detailed. The vehicle was
designed as a proof of concept for the use of oscillating foils as
the sole source of motive power for a cruising and…