补气降低射流泵汽蚀振动和噪声的实验研究  

EXPERIMENT STUD ON REDUCTION OF CAVITATION INDUCED VIBRATION AND NOISE OF JET PUMP BY AIR SUPPLY METHOD

作　　者：龙新平[1,2] 王丰景[1,2] 关运生[1,2] 

机构地区：[1]武汉大学动力与机械学院,武汉430072 [2]湖北省流体机械与动力工程装备技术重点实验室,武汉430072

出　　处：《振动与冲击》2008年第10期32-35,69,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(50579060)

摘　　要：对喉管低压区补气来改善射流泵汽蚀性能的方案进行了实验研究,得出如下结论:1)补气会将射流泵汽蚀时的噪声降低1 dB-8.7 dB。补气量越大,噪声降低效果越明显;2)在同一汽蚀条件下,工作压力越大,汽蚀所产生的振动加速度也就越大;在轴线方向,振动加速度随着补气量的增大而降低,但在水平和竖直方向补气前后振动加速度变化不大;3)补气可以明显降低扩散管及其出口的压力脉动,有利于泵性能的稳定和延长泵的使用寿命;4)补气后,射流泵的流量比有所变化,但变化不大。工作压力越大,补气后汽蚀流量比下降的越少,在某些情况下,补气后反而可以增大流量比;5)补气会破坏严重汽蚀时的液汽两相临界流动,大大改善流动的阻塞情况。成果表明,在喉管低压区自然补气简单可靠,易于实现,具有明显的降噪减振效果,可有效改善泵的汽蚀性能,可在工程实践中得到广泛的应用。Experimental study on improvement of cavitation performance of a water jet pump by air supply in the low-pressure region of the throat tube is carried out.It is found that:(1) The cavitation noise in the jet pump decreases about 1-8.7db by the air supply method.The higher air-supply flow rate,the more effective the noise reduction.(2) Under the identical cavitation conditions,the vibration acceleration induced by cavitation increases with the augment of the working pressure.In the axial direction,the vibration acceleration decreases with the increase in the air-adding flow rate.While in the horizontal and the vertical direction,the vibration acceleration has little change with the variation of air supply flow rate.(3) The pressure pulsation in the diffuser can be reduced greatly by the air supply method.This means that this method is good for the stabilization of operation and for extending the service life of the jet pump.(4) Flow rate ratio of the jet pump has a little change before and after air supplying.The higher the working pressure,the less drop the flow rate ratio with air supply.Under some operation conditions,the flow rate ratio of the jet pump will increase with air supply.(5) The supplied air will destroy the wavefront of the water-vapor two-phase critical flow and then improve greatly the flow choke condition.The above results reveal that the air supply method is a simple,and reliable method and also easy to operate,it can improve effectively the cavitation performance of a jet pump.

关 键 词：射流泵 补气 汽蚀 降噪 减振 压力脉动 文验研究 

分 类 号：TB53[理学—物理] TH38[理学—声学]