偏心度与间隙比对轴流泵流动激励力的影响  

Effect of eccentricity and clearance on the flow excitation force in axial flow pump

作　　者：王珏星 杨爱玲[1] 陈二云[1] 戴韧[1] 李国平 

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]中船重工第七O四研究所,上海200031

出　　处：《能源研究与信息》2014年第4期227-234,共8页Energy Research and Information

基　　金：上海市教委重点学科资助项目(J50501)

摘　　要：叶轮偏心将会引起轴流泵叶轮顶部间隙沿周向不均匀，从而导致附加的流动激励和噪声．利用计算流体力学商业软件 Fluent 模拟不同偏心度和间隙比的轴流泵非定常流场，研究周向非均匀间隙对泵内压强脉动及叶轮激励力的影响．结果表明：壁面压强脉动强度并不是在最小间隙处达到最大，而是出现在偏离最小间隙处约30°～60°的方向，并随着间隙比增大，脉动强度最大值发生位置逐渐向最小间隙处靠拢；同时，偏心造成的非均匀叶顶间隙引起了轴频处的压强脉动，在间隙比为2．5％下偏心度从0％增加到60％，轴频处的压强脉动相对增量为661．54％；叶轮受到的径向激励力时均值与偏心度呈线性关系，其斜率与间隙比的平方根成正比．Nonuniform tip clearance in axial flow pumps may cause mechanical vibration of the pump and generate larger hydrodynamic noise.The computational fluid dynamic（CFD） software of Fluent is employed to simulate the unsteady flows of the pumps with different relative eccentricities and clearance ratios.Then the influence of nonuniform clearance along circumference on the pressure fluctuation and excitation force is studied.The results show that the maximum pressure fluctuation does not appear at the minimum clearance,but appears at the position where the offset is between 30 degrees and 60 degrees.At the same time,the pressure fluctuation at the shaft frequency is caused by the nonuniform tip clearance.And it increases by 661.54% as the relative eccentricity varies from 0% to 60%with clearance ratio of 2.5%.When the clearance ratio increases,the occurrence of maximum fluctuation intensity transforms to the position of the minimum clearance slowly. Meanwhile,the simulation results also show that there is linear relationship between the time-average excitation force of the impeller and the eccentricity.And the slope is proportional to the square root of clearance ratio.

关 键 词：非均匀叶顶间隙 偏心度 间隙比 压强脉动 叶轮激励力 

分 类 号：TH312[机械工程—机械制造及自动化]