间隙尺寸对水翼叶顶旋涡空化流动影响的试验研究

发布时间：2018-08-30 10:41

【摘要】：采用试验方法对不同间隙尺寸的水翼叶顶旋涡空化流动进行研究.试验在闭式空化水洞中进行,应用高速全流场显示技术对旋涡空化形态进行观测,采用图像处理技术对结果进行处理,并对比分析间隙尺寸分别为0.5和2.0 mm的2种工况下间隙空化流动的发展规律.研究结果表明:随着空化数的减小,叶顶空化流动可以分为涡空化初生阶段、间隙内部附着空化发展阶段和剪切层空化发展阶段3个典型阶段;在涡空化初生阶段,大间隙工况下涡空化沿流动方向延伸距离大于小间隙工况;在间隙内部附着空化发展阶段,随着空化数的降低,大间隙工况下附着空化的初生和发展均领先于小间隙工况;在剪切层空化发展阶段,大间隙工况下剪切层空化形态趋于稳定时对应的空化数大于小间隙工况,并且其向下游延伸距离大于小间隙工况.
[Abstract]:Vortex cavitation flow at the top of a hydrofoil blade with different clearance sizes was investigated by experimental method. The experiment was carried out in a closed cavitation water tunnel. The vortex cavitation morphology was observed by high-speed full-flow field display technique, and the results were processed by image processing technology. The development of clearance cavitation flow under two conditions with clearance size of 0. 5 mm and 2. 0 mm respectively is analyzed. The results show that with the decrease of cavitation number, the cavitation flow at the top of the blade can be divided into three typical stages: the primary stage of vortex cavitation, the stage of internal attachment cavitation development and the stage of shear layer cavitation development, and the third stage is the primary stage of vortex cavitation. Under the condition of large clearance, the distance of vortex cavitation extending along the flow direction is longer than that of small clearance, and in the development stage of internal attachment cavitation, with the decrease of cavitation number, the initiation and development of attachment cavitation in large clearance is ahead of that in small clearance. In the developing stage of shear layer cavitation, the cavitation number of shear layer is larger than that of small gap when the cavitation shape of shear layer tends to be stable under the condition of large clearance, and the extension distance to downstream is larger than that of small gap.
【作者单位】：北京理工大学机械与车辆学院;
【基金】：国家自然科学基金重点资助项目(51239005);国家自然科学基金资助项目(51479002)
【分类号】：TK72

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