非牛顿流体在变截面管中流动的数值模拟  

Numerical Simulation on Non-newtonian Fluid Flow in a Variable Cross-section Tube

作　　者：李玉伟[1] 方小里[1] 李召生[1] 曹丽琴[2] 

机构地区：[1]哈尔滨锅炉厂有限责任公司,哈尔滨150046 [2]燕山大学环境与化学工程学院,河北秦皇岛066004

出　　处：《应用能源技术》2015年第4期1-4,共4页Applied Energy Technology

摘　　要：由于非牛顿流体的粘度随剪切速率而变化,使得其在流动时表现出十分复杂的规律,这给实际应用和研究带来困难。文中应用数值模拟方法对非牛顿流体在二维变截面管中的非稳态流动进行了研究。研究发现,对于非牛顿流体,考虑粘度随剪切速率变化时的工况与考虑粘度为固定值时的工况相比,流动更加复杂,流场也更加紊乱,管道中心区的速度明显增加;同时,在截面突然变化的区域,流体的压力和速度波动也更加剧烈,下游区域往往会形成大量的旋涡,这对流体流动的均匀性产生巨大的影响。在同一周期的不同时刻,流场中的压力和壁面剪切力也表现不同的变化物性。The viscosity of non - Newtonian fluid depends on the shear rate, which makes the flow very complex, and increases the difficulty to practical application and research work. This paper numerically studies an unsteady non -Newtonian flow in a two -dimension tube with variable across - section. It shows that for the non - Newton fluid, the pattern of the flow is more complex and the field is more disordered with a higher velocity at the centre of the tube in the case with the viscosity changing with the shear rate than in the case with a constant viscosity. In the region of the throat, the pressure and the velocity of the fluid fluctuate significantly and many vortices form at the downstream region, which have a significant contribution to the homogeneity of the flow. At different phases in a period, the pressure and wall shear stress performance differently too.

关 键 词：非牛顿流体 非定常流动 变截面管 旋涡 数值模拟 

分 类 号：TH138.1[机械工程—机械制造及自动化]