基于正交优化设计的诱导轮空化性能研究

为了研究不同结构因素对诱导轮空化性能的影响及主次顺序,基于正交优化设计,采用数值模拟的方法,通过诱导轮可视化试验进行验证,对某型诱导轮及其改型进行了分析。仿真计算得到的不同空化数下空穴形态与实验结果吻合较好,断裂空化数的计算结果与实验结果误差为0.3%。仿真及实验结果表明,诱导轮发生扬程断裂不仅与空穴区占流道体积的大小有关,还与空穴区在流道中分布的位置有关,空穴区位置越靠后,越容易发生扬程断裂;对诱导轮空化性能及水力效率影响最大的结构因素为入口安放角,其次为入口修圆包角;入口等螺距段长度和变螺距段长度较小时可以提高诱导轮的空化性能。

Study on Cavitation Performance of Inducer Based on Orthogonal Experiment

In order to study the influence and the priorities of different structural factors on cavitation performance of inducer, this paper analyzed the cavitation performance of an inducer and its modifications based on the orthogonal experiment and numerical simulation, the results were verified by the visualization tests. Cavity structures at different cavitation numbers predicted by simulation were in good agreement with the experimental results, the error of head coefficient between simulation and experimental results was 2.46% in design flow coefficient. Simulation and experimental results show that the head breakdown of inducer is not only related to the size of the cavity volume in flow channel, but also related to the distribution of cavities. When the distribution of cavities develop further inside flow channel, the easier the head breakdown would occur. Inlet blade angle has the greatest affect on cavitation performance and hydraulic efficiency, followed by the leading edge sweepback wrap angle. The cavitation performance of inducer could be improved when the length of inlet equal- pitch parts and variable- pitch parts are smaller.