九州大学大学院生物資源環境科学府生産環境科学専攻
Departmetn of Bioproduction Environmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University
九州大学大学院生物資源環境科学府生産環境科学専攻
Departmetn of Bioproduction Environmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University
自脱型コンバイン用揺動選別部を改良した揺動選別実験装置を製作し, これを用いて揺動棚振動数や供試材料の混合比を種々変えた揺動選別実験を行った. さらに, 揺動選別実験の DEM シミュレーションを行うとともに, 実験結果と解析結果を比較・照査することにより, DEM モデルの妥当性を検討した. その結果, 揺動棚振動数ならびに混合比の違いによる供試粒子の運動ひいては選別・分離現象を定性的に表現可能であることがわかった. さらに, DEM によるケーススタディとして揺動棚振動数を種々変えた解析を行った結果, 揺動棚振動数の差異による粒子挙動の変化を表現できることを示した. 特に, DEM 解析結果から最適な選別を行うための揺動棚振動数を推定できる可能性が示唆された. 今後は, 実際の籾と藁, 粃等の混合体を用いた現実に近い揺動選別実験や 3 次元 DEM による数値解析法の高度化を行っていく予定である.
Shaking separation test apparatus was developed by reconstruction of shaking separation unit in a commercial head-feeding combine harvester in order to improve the performance of shaking separation system. Shaking separation tests were conducted under various conditions such as the frequency of shaking table and mixture ratio of the particles tested. The motion of particles in the test was measured directly by using a high-speed camera. On the other hand, the numerical simulations on the shaking separation tests were carried out by DEM (Discrete Element Method) and its validity was verified by comparison with the test data. As a result, the behavior of particles simulated by the DEM agreed qualitatively with that observed in all the tests under the various conditions mentioned above. Case studies by the DEM were conducted for solving the mechanical behavior of particles under the various frequency conditions. The results would give the good suggestions to determine the optimal frequency condition for shaking separation system in the head-feeding combine harvester in particular.