力学与实践 ›› 2017, Vol. 39 ›› Issue (4): 354-358,378.DOI: 10.6052/1000-0879-16-393

• 应用研究 • 上一篇    下一篇

非稳态Couette流动阶段的边界位移与黏性能量耗散

闫彦   

  1. 中国石油化工集团公司发展计划部, 北京 100728
  • 收稿日期:2016-12-05 修回日期:2017-04-24 出版日期:2017-08-15 发布日期:2017-08-10
  • 通讯作者: 闫彦,高级工程师.E-mail:dayanxiaoli@163.com

BOUNDARY DISPLACEMENT AND ENERGY DISSIPATION IN UNSTEADY COUETTE FLOW STAGE

YAN Yan   

  1. SINOPEC Planning and Development Department, Beijing 100728, China
  • Received:2016-12-05 Revised:2017-04-24 Online:2017-08-15 Published:2017-08-10

摘要:

本文研究了牛顿流体非稳态Couette流动阶段的边界位移与流体黏性摩擦能耗.在上边界始终保持静止,下边界以恒定速度或恒定内壁剪切应力突然运动的情况下,建立了Couette非稳态流动的数学模型.求解定解问题,获得流体速度分布函数;通过渐近分析,获得不同边界条件下流动充分发展的临界时间,进而获得非稳态过程中的边界位移量.利用边界剪切应力和位移量的结果,计算非稳态过程中移动平板做功;再结合流体动能增加量,计算得出不同边界条件下非稳态流动阶段流体黏性摩擦能耗.

关键词:

边界位移|能量耗散|非稳态阶段|Couette流动

Abstract:

The boundary displacement in the unsteady Couette flow stage of Newtonian fluid is investigated in this paper. The top wall is always kept stationary and a constant velocity or a sudden constant tangential surface force is imposed on the bottom wall. The fluid velocity distributions are obtained by solving the problems. The time periods for the flow to reach the steady state under different situations are obtained by using the asymptotic analytic method. Then the boundary displacements in the unsteady stage are obtained from the time periods and the boundary velocities. With the shear stress on the inner surface of the bottom wall and the boundary displacements, the work done by the Couette system under different situations is obtained. From the increase of the fluid kinetic energy, the energy dissipations caused by the viscous friction in the unsteady Couette stage are obtained.

Key words:

boundary displacement|energy dissipation|unsteady state|couette flow

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