翼型流激噪声计算及实验研究

Calculation and experimental study on flow induced noise of hydrofoil

针对翼型绕流产生的湍流边界层脉动压力激励结构振动易引起流激噪声的问题,设计了三种不同尾缘(尖锐型、方型和鱼尾型)结构的翼型,采用大涡模拟(LES)和声振理论计算了其流场和声场,并在水洞中开展了声振特性实验研究,得到了不同攻角下各翼型的声振特性:各翼型的振动加速度总级和总声压级均随着攻角的增大而增大,其频谱曲线除峰值点外基本上随着频率的增大而减小.数值计算和实验结果均表明:尖锐尾缘翼型的振动和噪声最大,鱼尾型尾缘翼型的较小,可为水下航行器翼型的声学设计提供理论指导.

For the flow induced noise caused by structural vibration excited by fluctuating pressure in turbulent boundary layer generated by hydrofoil flow,three hydrofoils with different trailing edges(sharp,square and fishtail) were designed,and the flow field and sound field were calculated by large eddy simulation(LES) and vibro-acoustic theory.The vibro-acoustic characteristics of different trailing edges were studied experimentally, and the vibro-acoustic characteristics of each hydrofoil at different angles of attack were obtained,that is the total vibration acceleration level and total sound pressure level of each hydrofoil increase with the increase of attack angle, and the spectrum curve basically decreases with the increase of the frequency except peak points.Numerical calculations and experimental results show that the vibration and noise of the sharp trailing edge hydrofoil are the largest,while the vibration and noise of the fishtail trailing edge hydrofoil are smaller, which could provide theoretical guidance for the acoustic design of underwater vehicle hydrofoil.