摘要
The cavitation incipience and development of water flow over a thin hydrofoil placed in the test section of high-speed cavitation tunnel were investigated.Hydrofoils with smooth and rough leading edge were tested for different upstream velocities and incidence angles.The 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 whose 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°),it was found that cavitation incipience is significantly delayed by roughness while developed cavitation is almost the same for both smooth and rough hydrofoils.This unexpected incipience delay is related to the change in the boundary layer structure due to roughness.It was also reported a significant influence of roughness on the dynamic of developed cavitation and shedding of transient cavities.
The cavitation incipience and development of water flow over a thin hydrofoil placed in the test section of high-speed cavitation tunnel were investigated. Hydrofoils with smooth and rough leading edge were tested for different upstream velocities and incidence angles. The 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 whose 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°）,it was found that cavitation incipience is significantly delayed by roughness while developed cavitation is almost the same for both smooth and rough hydrofoils. This unexpected incipience delay is related to the change in the boundary layer structure due to roughness. It was also reported a significant influence of roughness on the dynamic of developed cavitation and shedding of transient cavities.
出处
《排灌机械工程学报》
EI
CSCD
北大核心
2017年第11期921-926,940,共7页
Journal of Drainage and Irrigation Machinery Engineering
基金
National Natural Science Foundation of China(51139007)
National “Twelfth Five-Year” Plan for Science&Technology Support(2015BAD20B01)
China Scholarship Council(201506350088)
作者简介
TAO Ran （1990-） ,male,master,doctoral student （ randytao@ cau. edu. cn） , researching in the flow analysis and design of hydraulic machinery.;XIAO Ruofu （ 1976-）, male, Ph.D. , professor （ xrf@ cau. edu. cn）, researching in the flow analysis and design of hydraulic machinery.
