摘 要：为研究在气液两相条件下液力透平内部的流动规律，选择比转速为55.7的单级单吸离心泵反转作液力透平（Pumps as Turbines，PAT），在考虑气体可压缩的基础上对该模型在不同流量、不同含气率下进行数值计算。分析含气率对液力透平外特性和液力透平各过流部件内流场的影响规律，总结不同工况下液力透平内气液两相流动规律。研究发现：随着含气率的增大，液力透平的效率和功率逐渐减小、扬程逐渐增加，气体的存在对液力透平效率影响较大；液力透平叶片进口有明显的旋涡，随着流量和含气率的增大，混合介质的相对速度均增加；含气率从液力透平进口到出口逐渐增大，叶片背面的含气率要比工作面大，过流部件内的气体分布不对称，随着含气率的变大，气体分布的均匀性变差。

Abstract:In order to analyze the internal flow of hydraulic turbine with gas-liquid two-phase medium,a single-stage and single-suction pump with the specific speed Ns=55.7 was numerically simulated at different flow rates and different gas rates with-gas compressibility considered.The influence of the gas content on the external characteristics of the hydraulic turbine and the flow field in the flow passage components were analyzed.The gas-liquid two-phase flow law of the hydraulic turbine under different working conditions was summarized.It was shown that as the GVF increases,the efficiency and power of the hydraulic turbine gradually decrease,while the head gradually increases.The existence of the gas has a great influence on the hydraulic turbine efficiency.There is a clear vortex in the hydraulic turbine blade inlet,and the relative flow velocity of the mixed medium increases with the flow rate and the gas content.The gas volume fraction increases from the inlet of the hydraulic turbine to the outlet,and the volume fraction of the gas on the back side of the blade is larger than the working side.The gas distribution in the flow passage components is asymmetric,and the uniformity of the gas distribution is deteriorated with the increase in GVF.

TH311

中国博士后科学基金面上资助（2016M600090）；国家自然科学基金（51279172）；四川省教育厅科研项目（17ZA0366）；西华大学自然科学基金（Z1510417）；西华大学省部级学科平台开放课题（szjj2016-004）