侧向进水口立轴旋涡数值模拟

Numerical Simulation of Vertical Vortex at Horizontal Intake

为了研究侧向进水口立轴旋涡的运动特性,以RNG模型为基础,引入VOF方法捕捉自由液面的变化,对立轴旋涡的形态及其运动轨迹进行了三维数值模拟,并对旋涡水面线和三维速度分布进行了分析。结果表明,侧向进水口前的旋涡是非对称的,其涡轴是一条空间曲线,旋涡下部在进水口的抽吸拉伸作用下发生扭曲。旋涡运动可分为三部分,第一部分水面线呈漏斗状,与对称旋涡类似,第二部分旋涡运动逐渐从竖向转为横向,第三部分为横向运动。在旋涡的上半部,轴向速度随着水深的增加而增大,当旋涡逐渐由竖向转为横向运动时,轴向速度逐渐减小直至为零。最大切向速度发生在淹没深度的52%处。

In order to study the motion characteristics of vertical vortex at horizontal intake,based on the model of RNG,introducing the VOF method to capture the change of free-surface,the 3-D numerical simulation was applied to research the form and moving trace of vertical vortex,and the vertical vortex water-surface profile and 3-D velocity distribution was analyzed.The results show that the vortex at horizontal intake is asymmetric,the vortex axis is a spatial curve.The lower part of vortex is distorted by the suction and tension from the intake.The motion of vortex can be divided into three parts.The water-surface of the upper part appears like a funnel,which is similar with the symmetrical vortex.The vortex of the second part moves gradually from vertical to lateral,and the third moves laterally.The axial velocity increases with the depth adding at the upper part of the vortex.When the vortex moves gradually from vertical to lateral,the axial velocity is diminishing until to zero.Maximum tangential velocity happens in 52 percent of submergence depth.