Effect of leading edge roughness on cavitation inception and development on thin hydrofoil  

作　　者：TAO Ran XIAO Ruofu FARHAT Mohamed 

机构地区：[1]Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Net- work System, China Agricultural University, Beijing 100083, China [2]Laboratory for Hydraulic Ma- chines, Ecole Polyteehnique Federale de Lausanne, Lausanne 1007, Switzerland

出　　处：《排灌机械工程学报》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)

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.

关 键 词：cavitation inception surface roughness sheet cavitation cloud cavitation HYDROFOIL 

分 类 号：S277.9[农业科学—农业水土工程]