Variation of ocean environmental parameters is important to sound ray propagation. This article studies the problem of sound ray propagation in seawater by BELLHOP ray model. The sensitivities of sound ray propagation...Variation of ocean environmental parameters is important to sound ray propagation. This article studies the problem of sound ray propagation in seawater by BELLHOP ray model. The sensitivities of sound ray propagation to the variations of seabed topography and depth of sound source by simulation. The results show that the depth variation of sound source is the main cause for emerging and disappearing of surface sound channel, accumulation area and deep sound channel. The deviation of sound ray propagation is in accordance with seabed topography change.展开更多
以某款实车为研究对象建立了统计能量分析(Statistical Energy Analysis,SEA)模型,通过传播特性分析对其主要传播路径进行分类,并进行简化模型近似性分析。通过对SEA模型中主要和次要子系统选取,建立了2种简化模型,对其车内噪声和传播...以某款实车为研究对象建立了统计能量分析(Statistical Energy Analysis,SEA)模型,通过传播特性分析对其主要传播路径进行分类,并进行简化模型近似性分析。通过对SEA模型中主要和次要子系统选取,建立了2种简化模型,对其车内噪声和传播路径的计算表明:模型子系统特性改变,能量的传播路径和大小特性随之变化、甚至子系统对外界流体脉动和声场的接受能力也发生变化,导致得到的车内噪声计算结果发生改变。简化模型的使用还需进一步研究。展开更多
Acoustic modal behavior is reported for an L-shape hydrophone array during the passage of a strong nonlinear internal wave packet. Acoustic track is nearly parallel to the front of nonlinear internal waves. Through mo...Acoustic modal behavior is reported for an L-shape hydrophone array during the passage of a strong nonlinear internal wave packet. Acoustic track is nearly parallel to the front of nonlinear internal waves. Through modal decomposition at the vertical array, acoustic modes are identified. Modal evolution along the horizontal array then is examined during a passing internal wave. Strong intensity fluctuations of individual modes are observed before and during the internal waves packet passes the fixed acoustic track showing a detailed evolution of the waveguide modal behavior. Acoustic refraction created either uneven distribution of modal energy over the horizontal array or additional returns observable at the entire L-shape array. Acoustic ray-mode simulations are used to phenomenologically explain the observed modal behavior.展开更多
文摘Variation of ocean environmental parameters is important to sound ray propagation. This article studies the problem of sound ray propagation in seawater by BELLHOP ray model. The sensitivities of sound ray propagation to the variations of seabed topography and depth of sound source by simulation. The results show that the depth variation of sound source is the main cause for emerging and disappearing of surface sound channel, accumulation area and deep sound channel. The deviation of sound ray propagation is in accordance with seabed topography change.
文摘以某款实车为研究对象建立了统计能量分析(Statistical Energy Analysis,SEA)模型,通过传播特性分析对其主要传播路径进行分类,并进行简化模型近似性分析。通过对SEA模型中主要和次要子系统选取,建立了2种简化模型,对其车内噪声和传播路径的计算表明:模型子系统特性改变,能量的传播路径和大小特性随之变化、甚至子系统对外界流体脉动和声场的接受能力也发生变化,导致得到的车内噪声计算结果发生改变。简化模型的使用还需进一步研究。
基金Supported by U.S. Office of Naval Research,Ocean Acoustics Program(322OA)under Nos.N00014-11-1-0701 and N00014-13-1-0306
文摘Acoustic modal behavior is reported for an L-shape hydrophone array during the passage of a strong nonlinear internal wave packet. Acoustic track is nearly parallel to the front of nonlinear internal waves. Through modal decomposition at the vertical array, acoustic modes are identified. Modal evolution along the horizontal array then is examined during a passing internal wave. Strong intensity fluctuations of individual modes are observed before and during the internal waves packet passes the fixed acoustic track showing a detailed evolution of the waveguide modal behavior. Acoustic refraction created either uneven distribution of modal energy over the horizontal array or additional returns observable at the entire L-shape array. Acoustic ray-mode simulations are used to phenomenologically explain the observed modal behavior.
