仿生蜗壳离心泵内部非定常流动特性分析

Analysis on unsteady flow characteristics in centrifugal pump with bionic volute

为了改善离心泵内部流场的非定常流动特性,基于仿生学原理构建仿生非光滑表面蜗壳,利用滑移网格技术对标准蜗壳、仿生蜗壳离心泵内部流场进行非定常计算,研究不同时刻下不同蜗壳离心泵静压场及速度场的差异,对比不同蜗壳离心泵压水室内压力脉动特性.结果表明:在不同时刻下,仿生蜗壳扩散段内静压分布更均匀、压力梯度更小,速度方向、大小基本保持一致,相对标准蜗壳更不易出现漩涡、二次流及边界层分离现象;叶片扫过隔舌瞬间,仿生蜗壳叶轮流道内流线分布相对更对称;一个周期内,仿生蜗壳离心泵压力脉动最大与最小处的脉动幅值均明显降低.说明仿生蜗壳能改善离心泵内部非定常流场,且对压水室内压力脉动有明显的抑制作用.

To improve unsteady internal flow characteristics in centrifugal pump,bionic nonsmooth volute was built based on bionics principle,sliding mesh technology was applied for calculation of unsteady internal flow field in centrifugal pump with standard and bionic volute.Discrepancies for different volutes under different times in pressure and velocity field were investigated and pressure fluctuation characteristics in pumping chamber for different volutes.Results show that the distribution of static pressure and velocity in the diffuser for bionic volute under different times are more uniform,and its are less prone to vortek,secondary flow and boundary separation phenomenons comparing to standard volute.When blade approaches the tongue,the distribution of streamline in impeller is more symmetrical.Pulsating amplitude of max and mix pressure pulsation for bionic volute drops evidently over a period of time.In addition,the structure of bionic volute can improve unsteady internal flow,and restrain pulsating amplitude in pumping chamber obviously.