基于CFD-EDM的自动投饵饲料颗粒气力输送数值模拟

Simulation of automatic pneumatic conveying process of automatic feeding system based on computational fluid dynamics-discrete element method

针对深水网箱自动投饵系统颗粒饲料气力输送时易阻塞与破损的问题,为揭示自动投饵系统中颗粒饲料的气力输送运动特性,开展了管道颗粒饲料气固两相流的数值模拟研究。基于气固两相流理论,分别建立了计算流体模型与离散元模型,通过计算流体力学与离散单元法(computational fluid dynamics-discrete element method,CFD-EDM)耦合求解,对饲料颗粒从气力输送管道初始阶段到稳定阶段的运动过程进行了分析,得到颗粒从初始状态到运动稳定阶段的颗粒位置分布情况。对不同位置管道内压力进行了分析对比,得到从管道入口到颗粒运动稳定状态时刻的压降。模拟仿真结果为自动投饵装备的模拟仿真与优化设计提供了参考,使其可以对饲料颗粒运动有更好的导向性,更好地降低弯管处颗粒碰撞的能量损失。

During the pneumatic conveying process of automatic feeding systems for deep-water off-shore cage culture, blockages of pipeline and damage to feed pellets occur easily. To reveal the pneumatic transport characteristics of pellet feed in automatic feeding system, a numerical simulation of gas-solid two-phase flow of feed pellets in a pipeline was carried out. Based on gas-solid twophase flow theory, both a computational fluid dynamics(CFD) model and discrete element model were established. The movement process of feed particles from initial stage to stable stage of pneumatic conveying pipeline was analyzed, and the position distribution of feed particles from initial stage to stable stage was obtained. Pressures at various locations in the pipeline were analyzed and compared to determine the pressure drop between the pipeline inlet and the instant at which the flow reached the steady state. The results provide references for the simulation and optimization design of automatic baiting equipment, which can better guide the movement of feed particles and reduce the collision energy loss of particles at elbow.