Characterisation of the Pump-Suction Flow Field of Antarctic Krill and Key Influencing Factors

To address the problem of high damage rates and low efficiency during Antarctic krill pumping, this study used Discrete Phase Modelling (DPM) computational fluid dynamics (CFD) to analyse how krill–water mixing ratios and centrifugal pump speeds affect flow dynamics and mechanical stresses. The simulation results show that a 4/6 krill-water ratio and a rotation speed of 550–600 rev/min minimise wall collision forces and krill crowding forces, thereby significantly reducing damage. Lower rotation speeds result in uneven force distribution, while higher rotation speeds have the potential to cause localised stress peaks. A mixing ratio deviation of 4/6 increases wall collisions (3/7) or interkrill crushing (5/5). These results provide a feasible guide for the design of krill suction pumps that will improve krill survival and contribute to the sustainability of the Antarctic krill fishery.