登录

  • 登录
  • 忘记密码?点击找回

注册

  • 获取手机验证码 60
  • 注册

找回密码

  • 获取手机验证码60
  • 找回
毕业论文网 > 毕业论文 > 理工学类 > 轮机工程 > 正文

水下椭圆柱壳声辐射与声散射试验方案设计毕业论文

 2021-11-14 09:11  

论文总字数:20084字

摘 要

水下目标声辐射特性和声散射特性是水下航行器和船只的声振特性的重要组成,并对水下目标的隐身性能方面有着重要的影响。例如潜艇和海上漂浮的船只,因为大多数这些海上交通工具可以近似为圆柱壳,所以各国学者已经对该壳的振动声特性进行了广泛的研究。但随着科学技术的发展,出现了越来越多的非规则圆柱壳结构的水下航行装置,这就需要我们对非规则圆柱壳结构开展进一步研究,本文对水下椭圆柱壳的声散射与声辐射特性进行了试验设计,意在完善水下椭圆柱壳声振特性研究的试验方法。

本文通过查找和翻阅相应的专业文献,对水下柱壳结构振动声辐射和声散射试验测试方法进行调研分析,详细了解其试验原理和方法,对比开阔水域、普通水池、消声水池测试的差异性及适用范围;结合椭圆柱壳声振特性,设计试验结构模型的参数,设计壳体模型、悬吊装置、换能器旋转装置、端盖板、配重选择等,试验在消声水池中进行,选择合适的试验测试设备,搭建试验测试平台方案。

通过功率放大器将激励力信号放大后驱动激振器,对壳体模型进行激励,使用加速度传感器采集加速度信号,模型振动向外辐射声压,在模型周围布置水听器来测量壳体辐射声压,分析实验结果完成对水下椭圆柱壳的声辐射试验设计。

通过换能器发射声波激励,水听器接收到目标模型的散射信号,使用线性调频信号(LFM)对散射声场作频域测量和分析,通过旋转装置连续旋转物理模型,同时在短时间内连续采集数据来进行测量,分析实验结果完成水下椭圆柱壳的声散射试验设计。

实验都在消声水池中完成,为了模拟一个没有反射的开阔水域声场条件,达到自由声场的试验条件,而普通水池由于水面,池壁,池底等对入射声造成的反射,会使试验测量的声辐射与声散射存在误差,而消声水池环境对试验声振的特性测量所造成的误差可以忽略不计。

关键词:水下椭圆柱壳;声辐射;声散射;试验设计

Abstract

Acoustic radiation characteristics and acoustic scattering characteristics of underwater targets are important components of acoustic vibration characteristics of underwater vehicles and ships, and have an important impact on the stealth performance of underwater targets. For example, submarines and floating ships, because most of these marine vehicles can be approximately cylindrical shells, scholars in various countries have conducted extensive research on the vibration and acoustic characteristics of the shells. However, with the development of science and technology, there are more and more underwater navigation devices with irregular cylindrical shell structures, which requires us to carry out further research on irregular cylindrical shell structures.

In this paper, the acoustic scattering and radiation characteristics of underwater elliptic cylindrical shells are experimentally designed in order to perfect the experimental method for studying the acoustic vibration characteristics of underwater elliptic cylindrical shells. In this paper, through searching and browsing the relevant professional documents, the test methods of vibration, sound radiation and sound scattering of underwater cylindrical shell structures are investigated and analyzed, the test principles and methods are understood in detail, and the test differences and application scope among open water areas, common water pools and anechoic water pools are compared. Combined with the acoustic vibration characteristics of elliptic cylinder shell, the parameters of the test structure model are designed, and the shell model, suspension device, transducer rotating device, end cover plate, counterweight selection, etc. are designed. The test is carried out in a silencing pool, appropriate test equipment is selected, and a test platform scheme is built.

The power amplifier amplifies the excitation force signal and drives the exciter to excite the shell model. The acceleration sensor is used to collect the acceleration signal. The vibration of the model radiates sound pressure outward. Hydrophones are arranged around the model to measure the radiated sound pressure of the shell. The acoustic radiation test design of the underwater elliptic cylinder shell is completed by analyzing the experimental results.

The hydrophone receives the scattered signal of the target model through acoustic excitation emitted by the transducer, and uses LFM to measure and analyze the scattered sound field in frequency domain. The physical model is continuously rotated by a rotating device while data are continuously collected in a short period of time for measurement. The acoustic scattering experiment design of the underwater elliptic cylinder shell is completed by analyzing the experimental results. The experiments are all completed in anechoic pool. In order to simulate the sound field condition in an open water area without reflection and achieve the test condition of free sound field, the reflection of incident sound caused by water surface, pool wall and pool bottom in ordinary pool will cause errors in the acoustic radiation and scattering measured in the test, while the errors caused by the anechoic pool environment on the measurement of the characteristics of acoustic vibration in the test can be ignored.

Key words:Underwater elliptic cylinder shell; Sound radiation; Sound scattering; Experiment design

目录

摘 要 I

Abstract II

第1章 绪论 1

1.1 研究背景 1

1.2 应用 1

1.3 国内外研究现状 2

1.4 研究目的和意义 5

1.5 本章小结 5

第2章 水下椭圆柱壳的声辐射试验 6

2.1 试验模型 6

2.2 试验布放 6

2.3 声辐射试验 7

2.3.1 试验设备 8

2.3.2 水下测试所用器材表 10

2.3.3 声辐射测试 11

2.4 本章小结 12

第3章 水下椭圆柱壳的声散射试验 13

3.1 试验模型 13

3.2 实验布放 13

3.3 实验装置 14

3.4 声散射试验 15

3.5 频域分析 16

3.6 不同水域中的差异性 17

3.7 本章小结 18

第4章 结论及展望 19

4.1 结论 19

4.2 展望 19

参考文献 20

致谢 23

第1章 绪论

1.1 研究背景

水下声辐射与声散射的研究一直以来是水声学的热点,水下目标对声波的散射特性及目标声辐射特性是影响水下航行体隐身的两个重要方面。例如潜艇和海上漂浮的船只,因为大多数这些海上交通工具可以近似为圆柱壳,所以已经对该壳的振动声特性进行了广泛的研究。

随着现在科技的发展,水下声对抗技术也不断发展,各种减震降噪技术使得被动声呐已经无法快速准确搜寻水下的目标特征,主动声呐成为水下目标探测的主要手段,被动声呐在辨别水下目标的特征时,快速性和准确性已经逐渐不能满足当今技术发展的需要,因此主动声呐更多的应用在水下目标探测的工作。振动辐射信号是水下目标发出的主要信号,通常作为声呐接收系统接收的信号,而主动声呐的接受系统在此基础上还增加了对目标散射声波信号的接收,也就是声辐射和声散射耦合形成的声信号。因此水下椭圆柱壳声辐射与声散射的研究对水下声对抗技术以及各种减震降噪技术的研究有着重要意义。

我国对水下柱壳振动的研究相对于发达国家来说起步较晚,经过长久以来的理论研究和实验验证,对于水下声辐射结构预报方面的技术,目前国内的掌握相对成熟,对水下结构振动声辐射的控制方法国内也掌握较多的方案,然而这些控制方法主要通过改变结构或覆盖阻尼材料,属于被动控制的方法,如果想在水下声波技术方面取得实质性的进展,就要摆脱材料和结构等因素对水下结构声辐射的贡献的影响,积极寻求主动控制技术的突破。

请支付后下载全文,论文总字数:20084字

您需要先支付 80元 才能查看全部内容!立即支付

企业微信

Copyright © 2010-2022 毕业论文网 站点地图