Journal Article

Simulation and Experiment on Structural Parameters of Three-Way Pipe in an Air-Blown Alfalfa Seed Metering Device Based on Fluent–Rocky Coupling

Chen, Wei, Wang, Yao, Zhang, Jin, An, Minhui, Lu, Biyun, Kuan, Qin, Xue, Kang, Wang, Liwei, Fan, Binbin, Wang, Chuan, Tang, Hao, Jiang, Zizhen

2026

Overview

To address the poor seeding uniformity and low stability of traditional seeders when sowing small, lightweight forage alfalfa seeds, this paper conducts a theoretical analysis of the key components of an air-blown alfalfa seeding mechanism. The Fluent–Rocky coupling simulation method is employed to investigate the effects of the structural parameters of the three-way pipe (contraction angle α and throat height h) on seeding performance. To obtain the optimal parameter combination, a two-factor, three-level orthogonal bench test was designed with throat height and contraction angle as independent variables. The results showed that when the contraction angle α was 20° and the throat height h was 18 mm, the coefficient of variation for seeding stability was 2.56%. Field validation tests indicated that under these parameter conditions, the average airflow velocity at the outlet of the seeding tube was 13.21 m/s, and the coefficient of variation for seeding stability was 3.09%, demonstrating good overall machine performance that met the requirements for alfalfa seeding operations. This study can provide a theoretical basis and technical reference for the optimal design of pneumatic seeding equipment for forage grass.

• Publisher: MDPI AG
• Subject: Accuracy / Analysis / Design / Discrete element method / Fluent-Rocky coupling / Fluid dynamics / Particle size / pneumatic seeding / Seeds / Simulation / Simulation methods / small-sized seeds / three-way pipe / Velocity