绕水翼加速流空化特性数值模拟  

Numerical Simulation of Accelerated Flow on Hydrofoil Cavitation

作　　者：施卫东[1] 张俊杰[1] 张德胜[1] 赵睿杰[1] 张琳[1] 

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,镇江212013

出　　处：《农业机械学报》2016年第4期1-7,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51479083);江苏高校优势学科建设工程项目;江苏省重点研发计划项目(BE2015001)

摘　　要：为了解翼型加速流动过程中空化特性,采用分离涡湍流模型(Detached eddy simulation,DES)和均相流空化模型对攻角为5.8°的NACA66(mod)水翼进行数值模拟,分析了空化数为0.99、对应雷诺数为8×105时绕二维水翼的非定常流动。通过模拟2种不同加速度(5 m/s2和2.5 m/s2)情况下空化演变过程和流场结构变化特征,得出了加速过程特有的变化规律:不同加速流下空泡都先在翼型的前缘产生,经过一段时间发展壮大,在翼型尾翼处分离,前缘处空泡减少,尾翼处空泡增加并向后衍生,直至破裂。空化产生于总加速时间的0.6倍左右,在总加速时间的1.12倍左右结束第一个周期。加速度越小,升力系数振荡范围越小,阻力系数振荡范围越大,空化发展过程越缓慢。In order to study the hydrofoil cavitation characteristics in the process of accelerated flow,detached eddy simulation（ DES） and homogeneous cavitation model were employed to simulate the unsteady flow around NACA66 model at attack angle of 5. 8°. The cavitation number was 0. 99 and the corresponding Reynolds number was 8 × 10^5. The characteristics of cavitation evolution and flow field structure were obtained in the case of two different accelerations（ a1= 5 m / s^2,a2= 2. 5 m / s^2）. Different numerical simulation results were obtained by studying different accelerations. Cavitation was first born in the leading edge of the hydrofoil,and grew after a period of time and finally separated. Then the cavitation in the leading edge was reduced and the cavitation at the tail of the hydrofoil was increased and backward spread until rupture. Cavitation was first generated at around 0. 6 times of total acceleration time and finished a cycle at about 1. 12 times of total acceleration time. Oscillation ranges of the lift coefficient became large and the range of the drag coefficient was small with the increase of acceleration.Using small acceleration,the cavitation developed more slowly. The simulation results obtained by DES turbulence model were more close to the experimental values than those obtained by homogeneous cavitation model. The research results can provide reference basis for cavitation characteristics study of hydraulic mechanical startup process.

关 键 词：水力机械 水翼空化 加速流 分离涡模型 

分 类 号：V211.1[航空宇航科学与技术—航空宇航推进理论与工程]