关键词: 螺旋流, 粒子图像测速技术, 垂直管, 流体流动, 轴向速度, 径向速度, 边界层, 压降

Abstract: In order to study the rules of spiral flow of the Newtonian and non-Newtonian medium fluids in the vertical pipe,the particle image velocimetry was used to measure the characteristics of the velocity field for the spiral flow of water and HPAM chromo with three kinds of mass concentrations in different tangential velocity.The distribution of axial velocity and radial velocity,the characteristics of the boundary layer and the relationship between pressure drop and tangential velocity of the spiral flow in the vertical pipe were investigated.It shows that the axial velocity is a kind of concave curve with double peaks.The trend of double peaks gets to be obvious with the viscosity increasing.The back flow is also observed in the axial direction.The radial velocity is anti-symmetrical as the center axis,and the thickness of the boundary layer is very thin.The calculation models are given for pressure drop of spiral flow of different media in the vertical pipe condition.

Key words: spiral flow, particle image velocimetry, vertical pipe, fluid flow, axial velocity, radial velocity, boundary layer, pressure drop