Abstract: To address the issue of feed breakage during hydraulic conveying in aquaculture that affects feeding efficiency and water environment. This study employs a CFD-DEM coupled method to develop a solid-liquid two-phase flow model for particle breakage. The research thoroughly investigates the breakage behavior of cylindrical feed particles within curved pipes during hydraulic conveying, with a particular focus on breakage types, fragment size distribution, and mechanisms of energy transformation and dissipation. The results indicate that feed particle breakage primarily manifests as surface peeling, occurring progressively under shear stress rather than via complete fracture. The size distribution of breakage products exhibits a bimodal pattern: large fragments retain the size of the parent particles, whereas small fragments are numerous but contribute relatively little to total mass. Energy dissipation is especially pronounced during collision-induced breakage, with up to 45.2% of energy lost during the initial breakage event, mainly due to the conversion of translational kinetic energy into internal and rotational kinetic energy. This study systematically reveals the breakage behavior of feed particles during hydraulic conveying from three perspectives—microscopic mechanisms, characteristics of breakage products, and energy transformation—providing a theoretical basis for optimizing hydraulic conveying processes to reduce particle breakage.

Key words: cylindrical feed, breakage characteristics, CFD-DEM, hydraulic conveying

摘要： 针对水产养殖水力输送中饲料破碎而影响摄食效率与水体环境的问题，本研究采用CFD-DEM耦合方法建立了固液两相流颗粒破碎模型，深入研究了水力输送过程中柱状饲料在弯管内的破碎行为，重点分析了破碎类型、碎片粒径分布以及能量转化与耗散机制。结果显示，饲料颗粒破碎主要表现为表面剥层，在切应力作用下发生渐进式剥离，而非整体断裂；破碎产物的粒径呈双峰分布，大尺寸碎片保持父代粒径，小尺寸碎片数量较多但质量占比较低；能量耗散在碰撞破碎过程中尤为显著，首次破碎可达45.2%，主要源于平移动能向内能和旋转动能的转化。本研究从微观机制、破碎产物特征和能量转化三个维度系统揭示了饲料颗粒在水力输送中的破碎行为，为降低水力输送过程中的颗粒破碎提供优化依据。

关键词: 柱状饲料, 破碎特性, CFD-DEM, 水力输送