FUNDAMENTAL STUDIES ON THE THREE DIMENSIONAL STRUCTURE OF LANGMUIR CIRCULATION

Abstract

  Most previous studies about laboratory measurements and field observations considered the properties of Langmuir circulations on the basis of streaky structures of convergence zones of mass and momentum. Therefore, there is almost no studies which could measure the secondary circulations with longitudinal axis under wind-induced water waves. In the present study, the secondary vortices, i.e., Langumuir circulations, could be measured successfully by PIV measurements, in which a high-speed camera was placed in the water body of the flume. It was found that the number of the secondary vortices is influenced by aspect ratio and wind-speed. Furthermore, phase analysis allowed us to understand that the structure of the secondary vortices depend significantly on the phase of water waves.