Experimental and Numerical Investigation of Centrifugal Pumps with Asymmetric Inflow Conditions  

作　　者：Sten Mittag Martin Gabi 

机构地区：[1]Institute of Fluid Machinery, Karlsruhe Institute of Technology KIT

出　　处：《Journal of Thermal Science》2015年第6期516-525,共10页热科学学报（英文版）

摘　　要：Most of the times pumps operate off best point states.Reasons are changes of operating conditions,modifications,pollution and wearout or erosion.As consequences non-rotational symmetric flows,transient operational conditions,increased risk of cavitation,decrease of efficiency and unpredictable wearout can appear.Especially construction components of centrifugal pumps,in particular intake elbows,contribute to this matter.Intake elbows causes additional losses and secondary flows,hence non-rotational velocity distributions as intake profile to the centrifugal pump.As a result the impeller vanes experience permanent changes of the intake flow angle and with it transient flow conditions in the blade channels.This paper presents the first results of a project,experimentally and numerically investigating the consequences of non-rotational inflow to leading edge flow conditions of a centrifugal pump.Therefore two pumpintake-elbow systems are compared,by only altering the intake elbow geometry:a common single bended 90°elbow and a numerically optimized elbow(improved regarding rotational symmetric inflow conditions and friction coefficient).The experiments are carried out,using time resolved stereoscopic PIV on a full acrylic pump with refractions index matched(RIM)working fluid.This allows transient investigations of the flow field simultaneously for all blade leading edges.Additional CFD results are validated and used to further support the investigation i.e.for comparing an analog pump system with ideal inflow conditions.

关 键 词：non-rotational symmetric inflow centrifugal pump intake elbow PIV RIM CFD 

分 类 号：TH311[机械工程—机械制造及自动化] V412.1[航空宇航科学与技术—航空宇航推进理论与工程]