摘要
半开式气液混输泵的叶顶泄漏涡往往伴随着较多的气泡,诱发泵的不稳定现象。为了研究泵内水气混合泄漏涡的动力学特性,本文基于欧拉-欧拉非均相双流体模型以及MUSIG气泡分布模型对三级半开式混流泵进行了数值模拟研究。采用高速摄像技术捕捉到了一个叶轮叶片周期内的叶顶泄漏涡轨迹、结构及其发展过程。研究结果表明:在叶顶间隙附近区域,科氏力项引起的涡量耗散最大,其次是拉伸扭曲项。膨胀收缩项和斜压扭矩项的大小比前两项下降一个数量级,且只在气液两相工况作用并随着进口含气率增加而增加。半开式气液两相泵的气相聚集区影响涡量耗散区的位置,叶轮的旋转作用是诱发涡量耗散的主要原因。
Tip leakage vortices(TLVs)in a semi-open gas-liquid mixed transport pump are often accompanied by a large number of bubbles,which induce instability in pump operation.This study numerically simulates the flows in a three-stage semi-open mixed flow pump using an Euler-Euler inhomogeneous two-phase flow model and a MUSIG bubble distribution model to study the dynamic behaviors of the TLVs with bubbles.High-speed camera technology is used to capture their trajectory,structure,and developing process in an impeller blade period.The results indicate that in the vicinity of the blade tip clearance,the largest dissipation of vorticity is caused by the Coriolis force term,followed by the stretch-twist term.Under gas-liquid two-phase conditions,the magnitudes of the expansion-contraction term and the diagonal torque term decrease by an order of magnitude compared to the first two terms,while they increase with the increase in inlet gas volume fraction(IGVF).Bubble accumulation zones in the impeller affect the position of vortex dissipation zones,and the rotation of the impeller is the main cause of inducing vortex dissipation.
作者
闫思娜
罗兴锜
冯建军
谢航
孙帅辉
朱国俊
YAN Sina;LUO Xingqi;FENG Jianjun;XIE Hang;SUN Shuaihui;ZHU Guojun(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China;Institute of Water Resources and Hydroelectric Engineering,Xi’an University of Technology,Xi’an 710048,China)
出处
《水力发电学报》
CSCD
北大核心
2024年第12期116-124,共9页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(52409119,52309118)
陕西省博士后科研基金(2023BSHEDZZ257)。
关键词
混流泵
气液两相流
涡动力学
数值模拟
mixed flow pump
gas-liquid two-phase flow
vortex dynamics
numerical simulation
