叶片包角是叶轮设计的重要参数，为探究包角对液力透平能量回收效率和运行稳定性的影响，采用UG建立流体域的三维模型，通过CFX软件将包角在50°~120°区间内的液力透平在额定工况下进行数值计算并进行外特性分析，选择75°、80°、85°三组包角方案进行内流特性分析与压力脉动频谱分析。研究发现：液力透平的效率随包角的增大先增大后减小，在包角80°左右时效率最高；包角的改变对叶轮内部的流场影响较大，合适的包角可以降低叶轮工作流道内的湍动能，使高速流体冲击叶片后的能量转换更加充分；蜗壳与隔舌处的压力脉动主要受动静干涉作用影响，主频为7fn，叶轮工作流道内主要受涡流影响，主频为2fn；将三种包角方案的时域图、频域图对比分析，发现包角对蜗壳、叶轮的压力脉动影响较大，对隔舌影响较小；包角为80°时，监测点rv5处的峰峰值与包角85°时相比降低了9.78%，显著提升了液力透平的运行稳定性。

The scroll of blade is an important parameter in impeller design. In order to explore the influence of wrap angle on the energy recovery efficiency and operational stability of hydraulic turbines, a three-dimensional model of the fluid domain was established using UG. The fluid turbine with wrap angle in the range of 50°~120° was numerically calculated and analyzed for external characteristics under rated conditions using CFX software. Three sets of wrap angle schemes, namely 75°, 80°, and 85°, were selected for internal flow characteristics analysis and pressure pulsation spectrum analysis. Research has found that the efficiency of a hydraulic turbine first increases and then decreases with the increase of the wrap angle, and the efficiency is highest at around 80° wrap angle; The change of the wrap angle has a significant impact on the flow field inside the impeller. An appropriate wrap angle can reduce the turbulent kinetic energy in the working flow channel of the impeller, making the energy conversion more complete after the high-speed fluid impacts the blade; The pressure pulsation at the volute and tongue is mainly affected by the interference of dynamic and static forces, with a main frequency of 7fn. The working flow channel of the impeller is mainly affected by eddy currents, with a main frequency of 2fn; Comparing and analyzing the time-domain and frequency-domain diagrams of the three envelope angle schemes, it was found that the envelope angle has a greater impact on the pressure pulsation of the volute and impeller, and a smaller impact on the tongue; When the package angle is 80°, the peak to peak value at monitoring point rv5 decreases by 9.78% compared to when the package angle is 85°, significantly improving the operational stability of the hydraulic turbine.

TV734；TK720

海南省省重点研发计划(ZDYF2021SHFZ057)；天津市自然科学基金重点项目(20JCZDJC00460)；中央级公益性科研院所基本科研业务费专项资金项目(K-JBYWF-2021-T07,R-JBYWF-2021-T02)