Experimental Investigation of Flow Patterns in a Pump Intake with Different CWL(Critical Water Level)and Back-Wall Clearance  

作　　者：GUO Miao TANG Xuelin LI Xiaoqin WANG Fujun 

机构地区：[1]College of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China [2]Beijing Engineering Research Centre of Safety and Energy Saving Technology for Water Supply Network System,China Agricultural University,Beijing 100083,China

出　　处：《Journal of Thermal Science》2021年第6期2150-2163,共14页热科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51909132,52079140,51779257).

摘　　要：In this study,influence of back-wall clearance,CWL(Critical Water Level)and air content in water on flow patterns in a pump intake has been investigated experimentally and theoretically for different cases.The statistical data show that CWL for a two-phase flow is lower than that in the case of a single-phase flow at a relatively low flow rate,and as the flow rate increases,this trend turns out to be completely reversed.Fine experimental data obtained under conditions of subcritical,critical and supercritical flow rates have revealed that the larger the back-wall clearance is,the more vortices exist and the higher the vorticity of free-surface vortices is.For the smallest back-wall clearance,the flow coming through the inlet occupies most space under the pipe bell,and both this flow and the inflow coming from the back wall are asymmetric relative to a certain vertical line other than the axis.For the larger and the largest back-wall clearances,the flows coming from the inlet and from the back wall are almost symmetrical relative to the vertical axis of the pipe bell.The velocity distributions on two PIV measurement lines for different back-wall clearance magnitudes indicate that the smallest back-wall clearance influences the flow around the pipe bell.

关 键 词：Critical Water Level(CWL) back-wall clearance air content in water pump intake 

分 类 号：TH38[机械工程—机械制造及自动化]