磁场作用下Oldroyd-B流体的非稳态驻点流动  

Unsteady Stagnation-Point Flow of Oldroyd-B Fluid along a Stretching Sheet with Magnetic Field

作　　者：白羽[1,2] 王清 张艳 

机构地区：[1]北京建筑大学,北京 [2]建筑结构与环境修复功能材料北京市重点实验室,北京

出　　处：《现代物理》2021年第1期1-8,共8页Modern Physics

摘　　要：本文研究了拉伸板上Oldroyd-B流体的非稳态驻点流动,此外,还考虑了磁场对流动的影响。利用合适的相似变换将控制方程转化为常微分方程。结合双参数变形展开方法与基函数方法(DPTEM-BF)求得微分方程的近似解析解。通过图形展示了各物性参数对速度场的影响,值得注意的是:随着松弛时间参数的增加,流体的粘性力增大使得流体流动阻力增强,这导致了流体流速减小;延迟时间参数的变化使得速度场增大,并且动量边界层厚度变厚;较大的磁场参数对应于较大的洛伦兹力,这个力阻碍了流体流动,因而流体流动速度降低。This paper examines the influence of magnetic field on unsteady stagnation-point flow of Oldroyd-B fluid towards a stretching sheet. Suitable similarity transformations are put into use to yield the ordinary differential equation, which are dealt with double-parameter transformation expansion method with base function method (DPTEM-BF). Impacts of various physical parameters on the velocity field are explored via graphs. It is noteworthy that as relaxation time parameter enlarges, the viscous force of fluid increases, which causes larger resistance to fluid flow. The increase of retardation time parameter increases both the velocity and momentum boundary layer thickness. Larger magnetic parameter corresponds to the larger Lorentz force, which impedes fluid flow and thus slows it down.

关 键 词：Oldroyd-B流体 非稳态驻点流动 磁场 DPTEM-BF方法 

分 类 号：G63[文化科学—教育学]