关键词：
双叶片离心泵;内部流场;粒子成像测速;计算流体力学
摘 要：
采用k-ε模型、SST模型和DES模型分别对比转数为70的前伸式双叶片离心泵进行非定常数值计算,获得不同流量工况下(Q/Qd分别为0.6、1.0、1.6)叶轮内部流场的相对速度分布,将不同湍流模型的内部流动模拟结果与PIV试验结果进行对比分析,发现基于k-ε模型的模拟结果与PIV试验测量结果较为吻合。采用k-ε模型对比转数为157的前伸式双叶片离心泵进行非定常数值模拟,研究发现叶轮内部流动规律与比转数为70的离心泵叶轮内部流动规律具有相似性:在流道中部靠近叶片工作面上存在低速区及与叶轮旋转方向相反的轴向旋涡,随着流量的增大,低速区与轴向旋涡逐渐减小;引入少叶片数离心泵内部流动理论,揭示了低速区和轴向旋涡存在和发展的内在机理。
译 名：
Flow Field in Forward-extended Double Blades Centrifugal Pump at Different Specific Speeds
作 者：
Lang Tao;Shi Weidong;Chen Keqiang;Li Wei;Ji Leilei;National Research Center of Pumps,Jiangsu University;
关键词：
Double blades centrifugal pump;;Internal flow;;Particle image velocimetry;;Computational fluid dynamics
摘 要：
This research was taken on probing the internal flow pattern of relative velocity flow field in the back-swept double blades centrifugal pump. Firstly,different turbulence models,including k-ε,SST and DES were used to do unsteady numerical simulation on the particle image velocimetry( PIV) test pump whose specific speed was 70. Secondly,PIV test was done on the pump and the relative velocity flow field distribution in the impeller was got. The results showed that numerical simulation results of k-εturbulence model were more consistent with PIV test results. By analyzing the distribution of relative velocity of the impeller whose specific speed was 70 under different flow rate conditions( Q / Qdwas 0. 6,1. 0,1. 6),the variation of axial vortexes and low-speed zones in the impeller was found out. When Q / Qdwas 0. 6 and 0. 8,there were low-speed zones and axial vortexes were opposite to rotation directions of impeller in the middle zone of channels nearby the pressure surface of the blades,and with the increase of flow rate,low-speed zones and axial vortexes decreased. Then k-ε turbulence model was used to do numerical simulation on the pump whose specific speed was 157,the results showed that the variation law of the relative velocity flow field distribution in the impeller was similar with that of PIV test pump. To explain the phenomenon,the theory of limited number blades in the centrifugal pump internal flow was introduced,which revealed the fundamental reason for the existence and development of the lowspeed zones and vortexes. The research results have an important reference value for the further research of the internal flow pattern of protrusive type twisted blades centrifugal pump.
