Study on hydrodynamic characteristics of multiple fish based on smoothed particle hydrodynamics

In this paper, the effect of spatial configurations and quantities of fish school on the hydrodynamic characteristics of fish is numerically investigated by smoothed particle hydrodynamics, revealing the hydrodynamic mechanism of the fish school in terms of shedding vortices and channel effects. In this study, the spatial configuration of fish school includes three types, namely, side-by-side, triangle, and staggered; the number of fish varies from one to six. The pressure, velocity, and vortex contours are discussed to investigate the hydrodynamic parameters of fish school. The results show that the shedding vortex has a greater effect on the hydrodynamic characteristics of fish school than the channel effect; as the longitudinal distance increases, the channel effect rapidly declines while the shedding vortex still generates an effect on the hydrodynamic characteristics of fish school at a relatively big longitudinal distance; the inverted triangular configuration has a stronger channel effect than the positive triangle configuration; the number of fish has a greater impact on the hydrodynamic characteristics of fish located at the back of the fish school than on the hydrodynamic characteristics of fish located at the front of the fish school.