Numerical Simulation of a Falling Sphere in Viscous Fluid

• Main Authors: KUAN-HUNG LIU, 劉冠宏
• Other Authors: Ching-Biao Liao
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/49787749231007189426

碩士 === 逢甲大學 === 水利工程與資源保育研究所 === 98 === In this study, we simulate a falling sphere in viscous incompressible flow by finite difference method. We apply immersed boundary method to solve solid boundary inside the fluid. That can effectively and quickly deal for complex irregular boundaries in Cartesian grid system. Previous studies discovered that falling sphere do have transverse displacement, and has a spiral trajectory in settlement process. Furthermore, the vortices are not symmetrical to sphere axis in settlement process, and terminal velocity was not a fixed value. We utilize Cate et al. (2002) experimental studies for a falling sphere in silicone oil. The simulation compared falling speed and trajectory data of sphere with their result to verify the accuracy of our model. This study change initial sphere position to produce transverse displacement. We investigate the trajectory and the flow field at high Reynolds number flow and the effect due to transverse displacement and sphere density.