Authors

Abstract

Corn kernels collide with the pipe wall during pneumatic conveying, which affects their quality. Based on the theory of oblique impact collision dynamics, this paper investigates the breakage of corn kernels at impact angles ranging from 10°~40°. The results show that secondary collisions have a significant effect on the normal restitution coefficient. As the impact angle increases, all three restitution coefficients tend to increase. At impact angles of 40° and above, the normal and overall restitution coefficients are related to the initial velocity, while the tangential restitution coefficient is not. At impact angles of 30° and above, the normal restitution coefficient is smaller at the top and larger at the abdomen, and the tangential and overall restitution coefficients are independent of the collision location. The three restitution coefficients when the rotation direction is in the same plane are all smaller than those when rotation occurs perpendicular to the translational plane, with the normal restitution coefficient being most affected by the direction. When the impact angle is between 30°~40°, the tangential restitution coefficient of corn kernels increases with increasing rotational speed. When the impact angle is between 20°~40°, the normal restitution coefficient decreases with increasing rotational speed. When the impact angle is between 10°~40°, the overall restitution coefficient is independent of the rotational speed.

Abstract in Chinese

玉米籽粒在气力输送中会与管壁碰撞进而影响自身质量，本文基于斜撞击碰撞动力学理论，研究了10°~40°撞击角度下玉米籽粒的破碎情况。结果表明：二次碰撞对法向恢复系数影响较大；随着碰撞角度增加，三种恢复系数均呈增大趋势；40°及以上时，法向及整体恢复系数与初速度相关，切向恢复系数与其无关；30°及以上时，法向恢复系数顶部小、腹部大，切向及整体恢复系数与碰撞部位无关；旋转方向在同一平面内的三个恢复系数均小于在垂直于平动面内发生旋转时的恢复系数，其中法向恢复系数受方向影响最大；30°~40°时，玉米籽粒切向恢复系数随转速增大而增大，20°~40°时，法向恢复系数随转速增大而减小，10°~40°时，整体恢复系数与转速无关。