离心泵内部非定常空化流动及其可视化

摘要

基于混合多相流模型，不同的湍流模型及完整空化模型，对比转数为86的离心泵内部流道的空化流动进行了定常和非定常的数值模拟，预测了空化初生阶段、发展阶段和空化严重阶段叶轮流道内空泡分布的形态特征。利用高速摄像机和设计的可视化离心泵，对空泡形态特征和连续时间内的叶轮内空化流场的观察与分析，获得了叶轮旋转过程中相邻叶片流道中非定常空化流动的变化规律。结果表明：拍摄所得空泡形态特征随NPSH的变化规律与数值计算结果基本一致，验证了数值计算的有效性；当某一叶片背面上或某一叶片流道内出现严重空化时，紧跟其后的叶片背面上或叶片流道内空化现象会受到抑制，但在其工作面上会出现明显的空化区。%Based on mixture model, full cavitaion model and various turbulence models,the steady and un-steady cavitating flow-passages in centrifugal pump with specific speed of 86 were numerically simulated. The morphological characteristics of cavitation at different stages were estimated.The cavitation morphologi-cal characteristics were catched through the high speed camera system and the visualization pump as well as the features and regularities of unsteady cavitating flow in adjacent blade passage.The simulation results in-dicate that the experiments results of the cavitation morphological characteristics which were observed are consistent with the simulation results proving its effectiveness.When a severe cavitation appears on the back of the blade or a blade runner, the cavitation of the next blade or passage will be suppressed, but cavitation zone will be appeared in the working surface.