间隙尺寸对水翼叶顶旋涡空化流动影响的试验研究  

Experimental investigation into influence of clearance size on cavitating vortical flows in hydrofoil tip

作　　者：刘雷鸣[1] 刘影[1] 赵宇[1] 王国玉[1] 

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《排灌机械工程学报》2016年第7期573-578,共6页Journal of Drainage and Irrigation Machinery Engineering

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)

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.Cavitating vortical flows in a hydrofoil tip with different tip clearance sizes are studied ex- perimentally. A series of experiments are conducted in a closed-loop cavitation tunnel. The cavities are observed with a high speed camera and are analyzed by using image processing. The cavitating flow de- veloping characters in the different size clearances （0.5 and 2.0 mm） are compared. Based on the re- sults, three typical cavitation stages can be defined with decreasing cavitation number, namely inci- pient cavitation （I）, attached cavitation （II） and shear layer cavitation （III）. In stage I, the stream- wise length of cavity in the big gap is larger than that in the narrow gap. In stage II, the attached cavi- ty inside the large gap develops faster than that in the small gap in both the cavitation inception and the developing phases with decreasing cavitation number. In stage III, the critical cavitation number for the formation of triangular shear layer cavitation in the large gap is higher than that in the small gap; meanwhile, the cavity extends further downstream in the large gap than that in the small gap as well.

关 键 词：水翼 叶顶间隙涡 空化 间隙尺寸 高速摄像 

分 类 号：S277.9[农业科学—农业水土工程] TK730[农业科学—农业工程]