摘要
为了分析双吸泵内部非定常空化流,采用SST湍流模型及基于Rayleigh-Plesset方程的输运空化模型,对双吸泵空化流场进行定常与非定常模拟,得到了双吸泵内流场空化初生部位及空化发展情况,并设置监测点分析了空化状态下双吸泵内不同位置处的压力脉动特性。结果表明,空化首先发生于叶片吸力面头部靠近前盖板处,随着空化余量的降低,空化面积及空泡体积分数不断增大,空化继续发展后,空泡会逐渐向叶片吸力面及叶轮出口扩散,从而降低泵的扬程;在一个旋转周期内,单个叶片上的空化状态呈现出由弱变强、再由强变弱的发展趋势;随着空化余量的降低,监测点处压力脉动幅值增加,蜗壳流道内压力脉动的主频为叶频,谐频为叶频的倍数,且蜗壳隔舌处的压力脉动幅值最大。
In order to analyze unsteady cavitation flow of double-suction pump,the SST turbulence model and transport cavitation model based Rayleigh-Plesset equation were used to simulate steady and unsteady cavitation of flow field in double-suction pump.The cavitation inception position of flow field in double-suction pump and the development of cavitation were obtained.And then the monitoring points were set up to analyze the pressure fluctuation characteristics at different locations in double-suction pump.The results show that the cavitation occurs at the front of the suction surface of the blade,and is close to the front cover plate;with the decrease of the cavitation margin,the cavitation area and the fraction of cavity volume are increasing;with the development of cavitation,the cavity will gradually move to the suction surface of the blade and the outlet of impeller;thereby,the pump head is reduced.In a rotation cycle,the cavitation at a single blade appears the development trend from weak to strong,and then from strong to weak.With the decrease of the cavitation margin,the pressure fluctuation amplitude increases at the monitoring point,and the pressure fluctuation amplitude of the tongue in the spiral case is the largest.
出处
《水电能源科学》
北大核心
2017年第5期167-171,共5页
Water Resources and Power
基金
国家自然科学基金项目(51279172)
西华大学重点科研基金资助项目(Z1510417)
西华大学省部级学科平台开放课题(szjj2016-004)
流体及动力机械四川省科研创新研究团队项目(x1404)
关键词
双吸泵
空化流动
非定常流动
压力脉动
double-suction pump
cavitation flow
unsteady flow
pressure fluctuation
