摘要
湍流边界层起伏压力模型是预报水听器阵流噪声及流激水下结构振动和声辐射的基础,但湍流边界层起伏压力模型(如Corcos模型)都为经验模型,含有多个需要试验确定的待定参数,其中包括点功率谱密度与迁移速度.在此利用一条20元小阵元(6mm)密排线阵在水洞中的测量数据估计湍流边界层起伏压力的波数频率谱,通过估计迁移峰谱密度级估计湍流边界层起伏压力的点功率谱密度级,利用高分辨率波数谱估计方法估计迁移波数并计算迁移速度.与利用单个水听器测量点功率谱密度及利用两个水听器相关时延测量迁移速度的方法相比,本文采用的方法在波数域分离了迁移峰和低波数的背景干扰,提高了置信度.数据分析结果表明,水洞中湍流边界层起伏压力的归一化迁移速度为0 75±0 05,点功率谱密度随流速的4～6次方增长.
The models of the turbulent boundary layer fluctuation pressure(TBLFP) are the basis for the prediction of the flow noise of hydrophone arrays and the vibration and radiation of underwater structure excited by flow However, the parameters of models (for example, the Corcos model) contain many parameters to be determined by the experiment including point power spectrum density and convection velocity. In this paper, the wavenumber frequency spectrum of the TBLFP was estimated by using the data collected with a 20_element_array The point power spectrum density of the TBLPF was estimated using the estimation of the spectrum density of the convection peak The convection velocities were calculated by the convection wavenumbers which were estimated by using high resolution wavenumber spectrum analysis method. The method in this paper removed the convection and the low wavenumber background noise in the wavenumber field compared with the method by a single hydrophone and the convection velocities estimated by the time_delay between the signals received by a pair of hydrophone. The analysis of the data shows that the relative convection velocity is 075±005 and the point power spectrum of TBLFP is increased with 4～6 power of the flow velocity.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
2003年第6期600-603,共4页
Journal of Harbin Engineering University
基金
水声技术国防科技重点实验室基金资助项目(00JS23.1.1).
关键词
湍流边界层起伏压力
流噪声
迁移速度
点功率谱密度
turbulent boundary layer fluctuation pressure
flow noise
convection velocity
point power spectrum density
