Study on the influence of queue modes on the hydrodynamic performance of fish schooling swimming

In this study, computational fluid dynamics (CFD) models were used to investigate how different queue patterns affect the hydrodynamic performance of fish schooling. Various queue modes—such as tandem, parallel, and rectangular—were simulated to analyze fish swimming behaviors and hydrodynamics. Results indicated that both the queue pattern and fish spacing influence collective fish swimming. In tandem queues, fish exhibited improved speeds, with leading fish showing a 39.3% increase in cruising speed compared to single fish at dy =0.3L. However, larger spacing led to decreased fish speeds, with two fish at dy =1.2L nearing the speed of a single fish (0.12 and 0.02L/s differences). In parallel queues, fish swimming speed was lower than that of a single fish, especially when dx =1.5D, with inner fish cruising at 49.9% of a single fish's speed. Yet, increased spacing at dx =4D saw speeds nearing equality (0.01L/s differences), suggesting reduced queue impact. Rectangular queues showcased varying fish speeds, notably with outer rear fish displaying superior propulsion. As spacing increased, all fish tended toward a single fish's speed. Analyses of single fish, including acceleration and wake interactions, revealed collective movement utilizing vortices to generate thrust and create low-pressure zones, thus enhancing hydrodynamics. This research sheds light on how queue modes and spacing affect fish collective behavior and swimming dynamics, offering insights into collective dynamics and biological behaviors.