Underwater PIV Systems*

Meaningful oceanographic PIV measurements cannot always be achieved within a conventional laboratory environment with digital cameras and pulsed laser positioned outside a wave flume or wide tank. Studying ship dynamics in a wide tank, for example, requires a PIV system that can be mounted onto a superstructure and towed, submerged alongside the model. A modular system of cylindrical torpedoes for housing cameras singly, in stereo pairs or even multi-camera configurations has been developed along with beam delivery and sheet or volume illumination optics that can be mounted rigidly relative to the cameras. Taking this concept further a stereo PIV system has been developed that can be submerged in the ocean and operated remotely from a distance of 1.5km for periods of days or weeks without being brought to the surface. Details of implementation and results from both systems are presented.