Effect of leading edge roughness on cavitation inception and development on a thin hydrofoil
TAO Ran1,2, XIAO Ruofu1, FARHAT Mohamed2
1.Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083, China； 2.Laboratory for Hydraulic Machines, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1007, Switzerland)
摘要 We investigate the cavitation incipience and development of water flow over a thin hydrofoil placed in the test section of highspeed cavitation tunnel. Hydrofoils with smooth and rough leading edge were tested for different upstream velocities and incidence angles. Our observations clearly revealed that cavitation incipience is enhanced by roughness at incidence angle below 2°. This is in line with the former reports, according to which roughness element decreases the wettability and traps a larger amount of gas. As a result, surface nucleation is enhanced with an increased risk of cavitation. Surprisingly, for higher incidence angles (>3°), we have found that cavitation incipience is significantly delayed by roughness while developed cavitation is almost the same for both smooth and rough hydrofoils. We argue that this unexpected incipience delay is related to the change in the boundary layer structure due to roughness. We also report a significant influence of roughness on the dynamic of developed cavitation and shedding of transient cavities.
通讯作者:
TAO Ran(1990—),male,master,doctoral student (randytao@cau.edu.cn), researching in the flow analysis and design of hydraulic machinery.
作者简介: XIAO Ruofu(1976—),male,Ph.D.,professor (xrf@cau.edu.cn), researching in the flow analysis and design of hydraulic machinery.
引用本文:
TAO Ran,, XIAO Ruofu, FARHAT Mohamed. Effect of leading edge roughness on cavitation inception and development on a thin hydrofoil[J]. 排灌机械工程学报, 2017, 35(11): 921-926.
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