Measurements of boundary-layer flow and boundary roughness over Campeche Bank, Yucatan

Abstract

Aseries of boundary-layer measurements was made at three anchor stations on Campeche Bank, Yucatan. Measurements consisted of current speed at six levels within 1.5 m of the bed, current direction, and stereophotographs of boundary. Analysis of the drag coefficient revealed that the boundary-layer flow was hydrodynamically transitional and the magnitude of the drag coefficient varied between 2·10 −3 and 6·10 −2 as a function of the flow conditions and bed configuration. These data appear to be representative of flows of an intermediate nature, not only in the observed variations of the drag coefficient with respect to Reynolds number but in the way that the drag coefficient correlates with other measurements made in low- and high-velocity environments, respectively.