Discrete element method for non-spherical feed particle transport in offshore truss cage aquaculture: Modeling and applications

IF 4.3 2区农林科学 Q2 AGRICULTURAL ENGINEERING

Aquacultural Engineering Pub Date : 2025-10-07 DOI:10.1016/j.aquaeng.2025.102644

Haibo Liu , Yunpeng Zhao , Chao Ma , Guangchen Jia , Zhan Zhang , Dong An

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引用次数: 0

Abstract

Optimizing feed utilization is a critical challenge in offshore aquaculture, where low efficiency and high costs persist due to difficulties in predicting feed dispersal. This study addresses this issue by employing a Computational Fluid Dynamics–Discrete Element Method (CFD-DEM) framework, featuring a non-spherical drag model, to analyze the transport and dispersion of feed pellets in a truss net cage. One-way coupling was utilized to simulate the trajectories of dilute concentrations of both short cylindrical (H/D = 0.2, 0.4, 0.6) and slender cylindrical (H/D = 2.24, 2.47, 2.83) pellets. The results reveal that under cross-flow conditions, the particle Stokes number (S_t) is significantly less than unity (S_t≪1), indicating that trajectories are primarily governed by the local flow field. The pellet aspect ratio was identified as a key determinant of rotational dynamics, slender pellets exhibited more vigorous rotation, which enhanced their spatial dispersion. Particle shape significantly influenced residence time. While slender pellets settled faster in still water, short cylindrical pellets had shorter residence times in the presence of a current. By accurately modeling small-scale particle dynamics within a large-scale environment, this research provides valuable insights for optimizing feed pellet geometry to enhance aquaculture efficiency.

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海上网箱养殖非球形饲料颗粒输运的离散元法：建模与应用

优化饲料利用是近海水产养殖的一个关键挑战，由于难以预测饲料扩散，该领域的低效率和高成本一直存在。本研究采用计算流体动力学-离散元法（CFD-DEM）框架，采用非球形阻力模型，分析了饲料颗粒在桁架网箱中的输送和分散。利用单向耦合的方法模拟了短柱（H/D = 0.2、0.4、0.6）和细长柱（H/D = 2.24、2.47、2.83）球团的稀浓度轨迹。结果表明，在横流条件下，颗粒斯托克斯数（St）明显小于单位（St≪1），表明轨迹主要受局部流场控制。颗粒长径比是颗粒旋转动力学的关键决定因素，细粒颗粒表现出更强烈的旋转，这增强了它们的空间分散。颗粒形状对停留时间有显著影响。细长的颗粒在静水中沉降更快，而短的圆柱形颗粒在水流存在下的停留时间更短。通过在大尺度环境中精确建模小尺度颗粒动力学，本研究为优化饲料颗粒几何形状以提高水产养殖效率提供了有价值的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Aquacultural Engineering 农林科学-农业工程

CiteScore

8.60

自引率

10.00%

发文量

审稿时长

>24 weeks

期刊介绍： Aquacultural Engineering is concerned with the design and development of effective aquacultural systems for marine and freshwater facilities. The journal aims to apply the knowledge gained from basic research which potentially can be translated into commercial operations. Problems of scale-up and application of research data involve many parameters, both physical and biological, making it difficult to anticipate the interaction between the unit processes and the cultured animals. Aquacultural Engineering aims to develop this bioengineering interface for aquaculture and welcomes contributions in the following areas: – Engineering and design of aquaculture facilities – Engineering-based research studies – Construction experience and techniques – In-service experience, commissioning, operation – Materials selection and their uses – Quantification of biological data and constraints