Experimental-laboratory study of the flow around mussel shocks

Abstract

The productivity in an organized mussel culture area is closely related to the hydrodynamics in the area where the mussel units are located. The interaction between the hydrodynamics and mussel farming in Chalastra (NW Thessalonikigulf) has been investigated during last decades. In the framework of the study of optimizing the quality of mussels production in mussel farming areas, a laboratory channel was designed, where the flow around and possibly through the mussel shocks would be studied in physical scale. The experiments were designed in physical/natural scale and the relevant variables were determined. Moreover, the specific positions for the measurements, the depth of the flow and the velocity currents were also determined. The following three mean velocity values of entrance water velocity U were used in the experiment; 5 cm/sec, 7 cm/sec and 9cm/sec. A basic research parameter used in the experiment was the distance between the mussel shocks. Four cases were taken into account: 300mm, 500mm, 700mm and 900mm. The final goal was the determination of the velocity field in the areas around the shocks. The velocity field was studied with the modern Particle Image Velocimetry technique. According to the above presented experiments, for distances between the shocks greater than 500 mm the velocity field is almost restored. Furthermore the case of larger distance between the shocks (i.e. 90cm) present the largest percentage of the velocity class 5-10cm/sec(occurring for entrance current velocities 7 and 9 cm/s)which seem to be the best range for mussel's growth.