Estimation of Drag Coefficient and Settling Velocity of the Cockle Cerastoderma edule Using Particle Image Velocimetry (PIV)

Abstract

Abstract This paper presents the results of a hydrodynamic study of a cockle population from the Ulla's estuary in Galicia (Spain). An analysis of the parameters has made it possible to determine the hydraulic characteristics of whole cockles during their threshold of movement and suspension. Dynamic analysis of the forces exerted on the submerged cockles led to a detailed characterization of a final population of 11 cockles, including their characteristic dimensions in addition to shell and body density. The friction angle between the existing sediment in the Ulla's estuary and the cockle shells was also recorded. The particle image velocimetry (PIV) laser technique was successfully applied to obtain an accurate calculation of the threshold velocity fields. This experimental tool provides the means to experiment with various approaches of the velocity governing the onset of motion and to obtain a more detailed definition of the parameters involved. Applying the PIV technique, three drag entrainment coeff...