基于近场测量的声速分层介质中辐射声场预测与计算方法

Middle- and high-frequency underwater transducers are widely used in underwater acoustic devices, and work in sound-velocity layered fluid media. Near-field measurement can be used to predict radiated sound field and avoid complicated modeling of the transducer and its radiated sound field. Furthermore, it can be used to estimate the working performance of an acoustic device before mounting on a platform (i.e., ship or underwater vehicle). However, the research of near-field measurement for middle- and high-frequency underwater transducer is insufficient, and near-field measurement and sound propagation in sound-velocity layered fluid media are researched separately, which causes errors in sound field prediction. Thus, this project intends to research three key scientific issues theoretically and experimentally, including near-field measurement theory for middle- and high-frequency underwater transducer, high-definition and high-precision measurement for middle- and high-frequency sound field, and coupling model of near-field measurement and acoustic propagation theory in sound-velocity layered fluid media. This project intends to establish a near-field measurement method for middle- and high-frequency underwater transducer and a computational method for predicting the radiated sound field in sound-velocity layered fluid media, and estimate the working performance of underwater acoustic device. The works in this project will benefit underwater acoustic device-device and device-platform collaborations and promote best performance of acoustic devices.

中高频水声换能器常用于各类声学设备，工作于声速随深度变化的连续分层介质声学环境。近场测量可用于预测换能器辐射声场，避开换能器及其外部声场的复杂建模，进而在安装到船舶、潜器等载体平台前，评估声学设备工作性能。然而目前针对中高频水声换能器的近场测量研究较少，并且近场测量与声速分层介质声传播通常作为两个方向分离开来研究，给声场预测带来较大误差。本项目围绕中高频水声换能器近场测量理论模型、中高频声场的高分辨率准确测量、近场测量与声速分层介质声传播耦合模型三个关键科学问题，开展近场测量理论和实验研究，旨在建立中高频水声换能器近场测量方法，进而将近场测量与声速分层介质声传播模型相结合，建立辐射声场计算方法，揭示声速分层对换能器辐射声场的影响规律，预测声学设备工作性能。本项目可为声学设备与载体平台集成优化，以及多声学设备协同工作提供重要依据，为声学设备实现最佳性能奠定基础，促使近场测量研究成果走向应用。

中高频换能器常用于各类声学设备，以实现探测、导航、通信等各类任务需求。本项目针对中高频换能器近场测量理论模型、中高频声场的高分辨率准确测量、近场测量与声速分层介质声传播耦合模型三个关键科学问题，开展了理论和实验研究，完成预定研究任务，取得相应的研究成果。本项目提出了中高频换能器的近场测量方法，该方法以Kirchhoff-Helmholtz积分方程为基础，针对中高频换能器较小的几何尺寸、障板安装条件和水下消声环境，具有计算简单高效的特点。进一步搭建了近场测量系统，在消声水池中开展实验研究，通过近场测量预测换能器外部辐射声场，与外部辐射声场的实测值进行对比，验证了本项目提出的近场测量方法的准确性。最终将近场测量与声速分层介质声传播模型相结合，以声速分层介质中的Green函数为纽带，建立换能器在声速分层介质中辐射声场的计算方法，对声学设备在工作水域的工作性能进行预测，并开展湖上实验进行考核验证，结果表明本项目提出的预报方法较为准确。本项目将近场测量应用于工作水域声速分层介质中辐射声场的计算，可促使近场测量的研究成果走向应用。利用本项目的研究成果，可在各类声学设备安装到载体平台前，对其工作性能进行预测并进行优化调整，这有利于促进声学设备与载体平台的集成优化，以及多声学设备协同工作，促使声学设备在载体平台和工作水域环境中实现最佳工作性能。