叶片载荷对离心泵内流动激励力及噪声的影响  

Effect of blade loading on fluid-induced exciting force and noise in centrifugal pumps

作　　者：杨爱玲[1] 徐洋[1] 李国平[2] 章艺[2] 

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]中国船舶重工集团公司第704研究所,上海200031

出　　处：《排灌机械工程学报》2014年第1期23-28,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(50976072);上海市教委重点学科建设项目(J50501)

摘　　要：基于大涡模拟技术和边界元方法分析离心泵内非定常流场及流动诱导的结构振动与噪声,研究叶片载荷对离心泵水力性能、流动激励力及流动噪声的影响.数值计算结果表明:相比于低叶片载荷的离心泵,高叶片载荷离心泵的水力效率提高了1.1%~2.9%,流场分布更均匀;相同工况下高叶片载荷离心泵的蜗舌压力脉动系数幅值比低叶片载荷泵高42.6%;叶轮受到的径向力脉动幅度也提高了7.63%;根据声场计算结果,蜗壳壁面振动速度在二阶叶频上最大,高叶片载荷离心泵蜗壳的最大振动速度是低叶片载荷离心泵的5~6倍;蜗壳振动向外辐射噪声的指向性分布也发生了变化,在10°~310°范围内高叶片载荷泵辐射的噪声声压级大于低叶片载荷泵.研究表明叶片载荷是影响离心泵内流动激励力和流动诱导振动与噪声的重要因素,低噪声低振动水泵的设计需综合考虑水力效率与泵内流动激励力.The unsteady three-dimensional turbulent flow fields in two centrifugal pumps are analyzed by using large eddy simulation method,then the structure vibration of the volute and the noise induced by the unsteady pressure are simulated with boundary element method. The pumps have an identical volute,impeller outlet diameter,blade outlet width,duty head and flow rate and rotational speed but different blade loadings. The hydraulic efficiency,flow field characteristics,pressure pulsation,volute vibration features and radiated noise from the pump are compared to investigate effects of the loading on hydraulic performance and fluid-induced exciting force. The results show that the hydraulic efficiency of the pump with the higher blade loading is not only 1. 1%-2. 9% better than that with the lower loading,but also has a more uniform flow field. The unsteady pressure on the wet surfaces of the volute and the exciting force applied on the impellers at blade passing frequency are dominated. The amplitude of pressure fluctuation in the pump with the higher blade loading is so remarkable that the maximum pressure fluctuation amplitude at the volute tongue is 42. 6% higher compared with that in the pump with the lower loading. Likewise,the magnitude of unsteady radial thrust fluctuation on the pump with the higher blade loading is increased by 7. 63% as well. The maximum vibration velocity and acceleration of the volute in the pump with the higher blade loading at the 2nd harmonic frequency is 5-6 times the frequency in the pump with the lower blade loading. Note that the directivity pattern of noise also shows an obvious difference in the two pumps,particularly,the sound pressure level from the pump with the higher blade loading is more violent than that with the lower loading in the range of 10°-310° polar angle. These results suggest that blade loading is an important factor that affects the exciting force and subsequently alters fluid-induced noise from a centrifugal pump. In addition,the hydraulic efficiency and exciti

关 键 词：离心泵 叶片载荷 流动激励力 大涡模拟 流动噪声 声振耦合 

分 类 号：S277.9[农业科学—农业水土工程] TH311[农业科学—农业工程]