螺旋离心泵固液流体分层效应的涡旋形成机理  

Formation mechanism of vortex by solid-liquid fluid stratification in screw centrifugal pump

作　　者：权辉[1] 李仁年[1] 苏清苗 韩伟[1] 程效锐[1] 申立新[1] 

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050 [2]兰州华宇航天技术应用有限责任公司,甘肃兰州730000

出　　处：《兰州理工大学学报》2014年第3期54-58,共5页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51079066);甘肃省自然科学基金(2011GS04252)

摘　　要：鉴于固液两相流在流体机械内部存在速度滑移现象,极易形成流体分层,导致压力梯度和密度梯度增大,进一步加剧了流体运动的复杂性,为讨论该情况下浮力效应对涡旋形成的机理,采用流体力学理论,利用数值模拟方法,对固液两相流在螺旋离心泵内部流动进行模拟和分析.结果表明:速度滑移现象在固相体积分数较大情况下更加明显,流体在各维度上分层使得浮力效应突出,该效应下等密度面线和等压线的斜交形成涡旋,同时,会使各流体层之间剪切力增大,流体呈现强非线性非定常湍流流动.结论揭示了浮力对于涡旋形成的作用机理,对于改善固液两相流在流体机械内部流动状况具有一定的指导意义.Due to the existence of velocity slip in the solid-liquid two-phase flow in the interior of fluid machine, fluid stratification is easy to take place, leading the pressure gradient and the density gradient to increase, further exacerbating the complexity of fluid motion. In order to discuss the case of buoyancy effect on formation mechanism of the vortex, fluid dynamic theory and numerical simulation method were employed to simulate and analyze solid-liquid two-phase flow in the interior of the screw centrifugal pump. The result showed that the velocity slip phenomenon would be more evident if the volume fraction was larger, fluid stratification with different dimensions would make the buoyancy effect prominent, and in this case the oblique crossing of isopycnal and isobar would form the vortex. Meantime, the shearing force between fluid layers would be increased, making the flow strongly nonlinear and non-stationary turbulent. Above conclusion revealed the buoyancy mechanism for vortex formation, which would be a guidance for improving the internal flow condition in fluid machine with solid-liquid two-phase flow.

关 键 词：螺旋离心泵 固液两相流 流体分层 浮力效应 涡旋 

分 类 号：TH311[机械工程—机械制造及自动化]