【作者】 刘胜柱；

【导师】 罗兴锜；

【作者基本信息】 西安理工大学 ， 水利水电工程， 2005， 博士

【摘要】 本文混流式水轮机部分是在国家自然科学基金重点项目《巨型混流式水轮机组振动与稳定性研究》(90410019)资助下完成。轴流式水轮机部分是在国家自然科学基金项目《水轮机间隙流动的试验和数值模拟研究》(50379044)资助下完成。本文对水轮机内部流动分析及性能优化进行了系统研究,并进行了试验验证,主要成果有: 本文根据水轮机通流部件几何形状的特点,采用拼接式多块网格技术,建立了网格块划分的拓扑方法,采用代数方法实现水轮机通流部件网格生成,能够快速实现全包角蜗壳、半蜗壳、导叶、混流式转轮、轴流式转轮、尾水管的高质量结构化网格生成。 提出了混流式水轮机转轮叶片进出水边外延方法和水轮机叶片参数样条曲面改型方法。建立了叶片改型与CFD分析的关系,并成功应用于三峡右岸等多个重点工程的水轮机研发。 通过水轮机各通流部件的数值模拟,改进了水轮机各通流部件的整体性能。采用k-ε模型数值模拟,得到了水轮机的数值效率,通过试验对比,混流式水轮机的数值效率在设计点附近与试验值具有很好的吻合,而远离设计工况计算结果偏差加大。 提出了在CFD分析中通过转轮出口环量控制改善压力脉动的方法,并成功解决了重大工程三峡水轮机模型试验中出现的高部分负荷压力脉动问题;通过性能优化,全面提高了三峡右岸水轮机的水力性能,使三峡右岸水轮机与左岸相比不仅效更多还原

【Abstract】 In this paper, the research achievements for the Francis turbine was supported by the National Nature Science Foundation of China (Grant No. 90410019), and the research findings for the Kaplan turbine were gained owing to the support of the National Nature Science Foundation of China (Grant No. 50379044). The flow field investigation and hydraulic performance optimization for the hydraulic turbine were carried out and the research results were verified by use of experimental investigations. The main research findings were as follows.Based on geometrical characteristic of through-flow components of reaction turbine and patched multi-block grid generating technique, the block topology for through-flow components of reaction turbine was achieved. The universal grid-generating program was developed on the basis of algebraic grid generation method. It could generate rapidly structured grids to describe the flow passage geometry of spiral case, Semi-spiral case, guide vanes, mixed-flow runner, axis-flow runner and draft tube of the reaction turbine.An algorithm to lengthen the inlet or outlet edge of the runner blade in the Francis turbine, and the blade redesign technical measure based on NURBS surface was put forward respectively. The relationship between blade redesign and flow field investigation in the turbine was constructed and a synthetical optimization performance technique of the turbine was brought forward according to the relationship. The synthetical optimization performance technique had been applied successfully to develop the Three Gorge turbine and the others.The whole performance of the through-flow components of reaction turbine was improved by use of the synthetical optimization performance technique based on numerical simulation.Using k-ε model numerical analysis, the numerical efficiency of thewater turbine was achieved, which accord with the test value near the design point. Whereas, the numerical efficiency of the water turbine that was away from the design point was departure from the test value.In this paper, based on CFD analysis a technical method, which is to improve pressure pulsation by means of controlling the velocity circulation distribution at runner exit, was put forward. The problem of pressure pulsation under high part load condition appeared in the turbine model test of the Three Gorge Project was solved drastically. Through performance optimization, the hydraulic performance of the turbine on the right bank of the Three Gorge Project was improved, and high efficiency and low cavitations coefficient were obtained. In addition, the pressure pulsation performance was advanced materially compare with the turbine on the left bank. This technique was applied in the turbine on the right bank of the Three Gorge Project, thus lead to the success in the international tender.The influence of flange clearance of axis-flow runner on the runner ?fficiency, leakage flow volume, main flow and the occurring position of the clearance vortex were discussed respectively.How to select a position of the guide vanes and runner interface was discussed through analyzing the influence of the selected different interface on the numerical simulation results. Based on the study of matching relation of the guide vanes and runner interface, the performance of axis-flow turbine was optimized.Based on the Reynolds-stresses model and k-e model, under the best operation condition the numerical simulation of axis-flow turbine was conducted respectively. The computational solution indicated that the Reynolds-stresses model did not take on its advantage, whereas show a shortage of long calculating time expense. The prediction value of clearance vortex, which was gained by the whole machine simulation, was closer to the test value than one that was obtained by single component simulation.According to the test result, the clearance vortex occurring was related to the blade incidence angle. The more the incidence angle is, the more the clearance vortex is. The damage of clearance vortex to the blades is the main factor. The position and size of clearance vortex varied with operation condition change. The clearance flows on flange have five cavitations forms. The five forms vary with the blade open position, one or two be likely to occur at the same time*更多还原