Numerical study of hydrofoil surface jet flow on cavitation suppression  

作　　者：WANG Wei LU Shengpeng XU Ruiduo YI Qi WANG Yayun WANG Xiaofang 

机构地区：[1]Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education,Dalian University of Technology

出　　处：《排灌机械工程学报》2017年第10期829-834,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：supported by the National Key Basic Research Special Foundation of China (2015CB057301)

摘　　要：Cavitation caused vibration and noise of hydraulic machinery. To some extent,cavitation made fatigue damage in advance. Many scholars found that the re-entrant jets were the reasons of the shedding of cavities. To suppress cavitation,based on the idea of blocking the re-entrant jets,a special surface flow structure of 2D hydrofoil was proposed. The through-hole was made in the proper position of the hydrofoil. The incoming flow can outflow from this jet-hole automatically depending on the pressure difference between pressure side and suction side. Re-entrant jet growth can be weakened by optimizing the jet-hole geometry. Based on the standard k-ε turbulence model and Schnerr & Sauer cavitation model,under different cavitation numbers( σ) and jet-angles( β) for NACA0066( 2D) hydrofoil with 8° angles of attack,cavitation field numerical analysis was carried out. The results show that 2D hydrofoil cavitation flow had a strong unsteadiness. Making a jet-hole at the junction between the re-entrant jet and cavity can effectively minimize cloud cavitation. For a certain cavitation condition,optimal jet-angles( β) can be obtained to control cavitation growth. For the same β,the effects of cavitation suppression were changed with different cavitation numbers( σ). Consequently,suitable jet-angle and jet-position could extend the stable operating range of the hydrofoil.Cavitation caused vibration and noise of hydraulic machinery. To some extent,cavitation made fatigue damage in advance. Many scholars found that the re-entrant jets were the reasons of the shedding of cavities. To suppress cavitation,based on the idea of blocking the re-entrant jets,a special surface flow structure of 2D hydrofoil was proposed. The through-hole was made in the proper position of the hydrofoil. The incoming flow can outflow from this jet-hole automatically depending on the pressure difference between pressure side and suction side. Re-entrant jet growth can be weakened by optimizing the jet-hole geometry. Based on the standard k-ε turbulence model and Schnerr ＆ Sauer cavitation model,under different cavitation numbers（ σ） and jet-angles（ β） for NACA0066（ 2D） hydrofoil with 8° angles of attack,cavitation field numerical analysis was carried out. The results show that 2D hydrofoil cavitation flow had a strong unsteadiness. Making a jet-hole at the junction between the re-entrant jet and cavity can effectively minimize cloud cavitation. For a certain cavitation condition,optimal jet-angles（ β） can be obtained to control cavitation growth. For the same β,the effects of cavitation suppression were changed with different cavitation numbers（ σ）. Consequently,suitable jet-angle and jet-position could extend the stable operating range of the hydrofoil.

关 键 词：HYDROFOIL CAVITATION suppression jet flow lift-to-drag ratio 

分 类 号：S277.9[农业科学—农业水土工程]