等温条件下球形颗粒沉降的轨迹特性

采用粒子图像测速仪研究了球形颗粒在重力作用下沉降的流场特性，研究了同一雷诺数(Re)下不同释放位置、同一释放位置不同Re下的颗粒沉降的规律. 结果表明，Re≤100时，同一Re下不同释放位置，颗粒最终稳定沉降位置均在中心处. 颗粒的释放位置沿中心线对称时，颗粒沉降的轨迹线沿中心位置对称；同一释放位置不同Re下，随Re增加，颗粒最终沉降轨迹由稳定的直线下降变为稳定的周期性摆动下降.颗粒的平衡位置与颗粒的初始释放位置及Re无关，但颗粒沉降的轨迹形状与释放位置及Re有关. 模拟结果与实验结果几乎一致.

Trajectory Characteristics of Spherical Particle Sedimentation under Isothermal Conditions

Trajectory characteristics of spherical particle sedimentation under the effect of gravity were studied using particle image velocimetry，PIV. The law of particle sedimentation, the experiment of different releasing locations under same Reynolds numbers and the same releasing location under different Reynolds numbers were examined. The results show that when Re≤100, despite different globule releasing locations, final stable settlement position of the particles was at the center under the same Re. When the particle's releasing position was symmetrical along the centerline, the trajectory of the particle sedimentation was also symmetrical along the center. With the increase of Re, the final sedimentation trajectory of the particle changed from a stable straight line to a stable periodic swing curve. In conclusion, the equilibrium position of the particles was independent of the initial release position of the particles and the value of Re, but the trajectory of the particles was related to the position and Re. The simulated and experimental results were almost the same.