摘要
针对弹性水翼在流体作用下变形较大的特点,采用计算流体动力学(CFD)方法计算水动力载荷,采用有限元法计算结构响应,建立了双向流固耦合计算方法.在计及结构变形的情况下计算得到了NACA66mod型水翼的稳态流场和压力脉动,发现水翼在雷诺数为7.5×10~5,攻角4°~6°之间发生转捩现象.基于得到的脉动压力,结合模态叠加法和声学边界元法,建立了流致噪声计算方法.数值计算结果表明:在转捩发生后,流致噪声主频处峰值降低;雷诺数每增加1.5×10~5,各成分的声压级增幅约为3dB,主频增幅约为25 Hz;流噪声由压力脉动决定,振动噪声由结构固有特性和激励力共同决定;对于总声压级,水翼流噪声较其自身振动噪声大,振动噪声在近壁面处衰减较快,而流噪声在远场衰减较快.
As flexible hydrofoil deforms too much under fluid impact,the hydrodynamic load was calculated by computational fluid dynamics（CFD）method and structural response was calculated by finite element method.A two-way fluid structure interaction numerical method was established.The steady flow field and pressure fluctuation of NACA66mod hydrofoil were obtained with the method under structural deformation,and numerical results illustrate that transition happens to the hydrofoil at attack angle of 4°-6°and Reynolds number of 7.5×10-5.Based on the fluctuation pressure,a flow induced noise calculation method was established with mode superposition method and acoustical boundary element method.Numerical calculation results show that main frequency peak of the flow induced noise reduces after transition;the main frequency and sound pressure level of the two components increase by 25Hz and 3dB with Reynolds number increasing by 1.5×10-5,respectively;flow noise depends on pressure fluctuation while vibration noise depends on structural natural characteristics as well as excitation force;for overall sound pressure level（SPL）,the flow noise of hydrofoil is greater than its own vibration noise;vibration noise damps faster near the wall while flow noise damps faster in far field.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2017年第11期87-91,102,共6页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51579243)
关键词
弹性水翼
流固耦合
转捩
流噪声
振动噪声
flexible hydrofoil
fluid structure interaction
transition
flow noise
vibration noise
