摘要
为了获得柱状物的轨迹和取向演变过程,对旋转直扩张通道中的柱状物悬浮流进行了数值模拟.采用Laplace方程生成通道的数值网格,使用有限体积法求解流场,然后采用Runge-Kutta法沿轨迹积分Jeffery方程来获得柱状物的取向演变.通过求解概率分布函数获得柱状物稳态取向分布.结果表明,流场的进口速度和柱状物所处的进口位置对于柱状物的取向演变具有重要影响,而通道的旋转速度和柱状物的初始取向对于柱状物的取向演变影响不大.当柱状物的长径比大于5时,取向分布对于长径比的变化不敏感;小于5时,长径比越小,柱状物旋转的速度越快,并且出现指向围绕流动方向振荡的情况越频繁.柱状物的取向总体上朝着流线方向,在壁面附近这一现象更为明显.结论对于含柱状物悬浮流泵送过程的研究具有参考价值.
To obtain the evolutions of cylinder trajectory and orientation,the cylinder suspension flowing through a rotating straight expansion duct was simulated numerically.The Laplace equation was used to ge-nerate the numerical grids of the duct,and the FVM was used to solve the flow field.Then the Runge-Kutta method was adopted to integrate the Jeffery equation along the trajectory to obtain the cylinder orientation.The probability distribution function was solved to get the steady cylinder orientation distribution.The results show that the fluid velocity at inlet and inlet position of cylinders located have significant effects,and rotation velocity of duct and initial cylinder orientation have insignificant effects on the orientation distribution of cylinders.The orientation distribution of cylinders is not sensitive to the variation of cylinder aspect ratio when the aspect ratio is larger than 5.For the cylinders with aspect ratio less than 5,the smaller the aspect ratio,the faster cylinders rotate,and more frequently cylinders swing around the flow direction.Cylinders generally orient along the flow direction,which is more obvious in the region near the wall.The conclusion is helpful to the investigation on the pumping process of suspension containing cylinders.
出处
《排灌机械工程学报》
EI
2010年第5期422-427,共6页
Journal of Drainage and Irrigation Machinery Engineering
基金
浙江省重大科技专项基金资助项目(2008C01024-4)
关键词
柱状物悬浮流
旋转
扩张通道
取向
数值模拟
cylinder suspension
rotation
expansion duct
orientation
numerical simulation
