船舶舱室的中高频振声仿真及传递路径研究

发布时间：2019-05-29 00:25

【摘要】：随着我国对海洋开发利用的进一步深入,运输船舶和海洋工程装备的动力性能逐步增强,动力装置引起的振动和噪声对船上人员的影响日益凸显。IMO和各船级社都对舱室的噪声等级做出了严格的限制,对船舶的设计和建造都提出了新的要求。在船舶设计阶段进行振声预报,制定有效的降噪方案,有助于从源头控制舱室中的噪声,避免反复试验和改进耗费时间、人力和物资成本,降低整体费用。中高频噪声是舱室噪声的主要组成部分,研究船舶系统的噪声来源、传递路径及控制方法,对提升船舶行业和国防工业的设计、制造水平具有重要意义。然而,由于船舶结构庞大的计算规模,对船舶的振声仿真精度较低,迄今的研究大多停留在定性分析的阶段;而中高频振声问题的不确定性,导致传统传递路径分析方法对这些频带的问题并不适用。这显然无法满足船舶工程领域减振降噪的需求,因此亟须发展新的求解方法。本文以船舶的中高频振动和噪声为分析对象,以降低人员生活舱室振动和噪声为目标,改进现有的计算方法,并提出区别于传统方案的中高频振声传递路径分析方法,确定了舱室噪声的主要来源,制定了切实可行的减振降噪方案。本文的主要研究内容和结论如下:(1)分析了中频和高频振声仿真方法的求解特点和选取依据。分别采用有限元-统计能量分析(FE-SEA)混合法和统计能量分析(SEA)法求解复杂系统的中频和高频振声问题,根据结构特征尺寸与内波长关系区分两类方法的求解区间,并据此建立了某船的FE-SEA混合模型和SEA模型,分别用于中频和高频振声问题求解。(2)提出部分FE子系统建模方法和局部模态参数摄动(LMP)法,提高中频问题的求解效率。针对FE-SEA混合法求解大型存在计算效率不足的缺点,仅选取靠近振声源舱室的部分子系统使用确定方法进行描述,其它次要部分结构采用统计方法描述,并使用LMP法分析强耦合结构之间的耦合损耗因子(CLFs),在降低中频问题求解规模的情况下保证仿真结果的准确。(3)确定了机舱主要振声源对人员活动舱室的贡献量。结合台架和实船测试数据,对200～8000 Hz频带的的噪声进行了仿真,分别计算了主机、发电机组和螺旋桨振动和辐射分量在舱室中产生的噪声。结果表明,主机和发电机组的振声分量是噪声的主要来源,螺旋桨的分量可以忽略。(4)提出使用图论算法求解中高频振声能量的传递路径。将中高频振声系统等效为图论框架下的能量传递网络:SEA子系统看作网络图的结点,而根据损耗因子能够得到结点之间有向边的能量传递权重,从而构成SEA赋权有向图。利用图论中的偏离算法求解源结点到目标结点权重最大的K主要路径(KDP),即可得到中高频振声能量的主要传递路径。最后,利用中心性测量方法评价结点在能量传递中的重要性,进而确定在能量传递中起主要作用的关键结构。(5)精细化路径分析对象的选取方法,降低路径计算的复杂度。引入振声温度的概念,根据子系统的能量、模态数和波数计算子系统的温度,确定能量的单向流动,将高于目标子系统的局部结构作为为路径分析对象,减少路径分析的结点和耦合连接数目,降低计算规模。(6)基于中高频振声仿真和传递路径制定了某船的降噪方案。在全船仿真的基础上建立图形网络,求解主机和发电机组到目标舱室中的KDP,并通过中心性测量确定在能量测量中起主要作用的结构和耦合连接。结果表明,对振动影响最大的是输入组和路径组结点,对应主机舱和辅机舱内底以及它们之间的垂直舱壁。采用阻振质量在这些关键结点位置施加减振降噪措施,可使发电机组在附近人员生活舱室的噪声降低5.59 dB(A)。本文的研究不仅解决了 FE-SEA混合法和SEA法在工程应用中存在的部分问题,而且为中高频振声传递路径的求解提供了一种可行的解决方法。图论算法在路径分析中的应用,为复杂系统中能量传递路径分析提供了巧妙的求解方案,量化了局部结构在系统能量传递中的作用,取得了一系列具有工程实用价值的结论,对船舶等复杂系统的噪声设计具有一定的参考价值。
[Abstract]:With the further deepening of the development and utilization of the ocean, the dynamic performance of the ship and the offshore engineering equipment is gradually enhanced, and the vibration and noise caused by the power device are becoming more and more prominent on the personnel of the ship. IMO and the classification societies have made strict restrictions on the noise level of the cabin, and new requirements for the design and construction of the ship are put forward. In the design phase of the ship, the vibration prediction is carried out, and an effective noise reduction scheme is developed to help control the noise in the cabin from the source, so as to avoid the repeated test and improve the time, the manpower and the material cost and reduce the overall cost. The high-frequency noise is the main part of the cabin noise, and the noise source, the transmission path and the control method of the ship system are studied. It is of great significance to improve the design and manufacture level of the ship industry and the national defense industry. However, because of the large scale of the ship's structure, the accuracy of the acoustic simulation of the ship is low, and the research to date is mostly in the stage of the qualitative analysis; and the uncertainty of the high-frequency vibration problem leads to the problem of the traditional transmission and analysis method to these frequency bands and is not applicable. This obviously does not meet the requirements of vibration reduction and noise reduction in the field of ship engineering, and therefore it is urgent to develop a new solution. Based on the high-frequency vibration and noise of the ship, this paper aims at reducing the vibration and noise of the people's living cabin, improves the existing calculation method, and proposes a method for analyzing the high-frequency and high-frequency vibration transmission in the traditional scheme, and the main source of the cabin noise is determined. And a practical vibration reduction and noise reduction scheme is developed. The main research contents and conclusions of this paper are as follows: (1) The solution characteristics and the selection basis of the intermediate frequency and the high-frequency vibration sound simulation method are analyzed. A finite element-statistical energy analysis (FE-SEA) method and a statistical energy analysis (SEA) method are used to solve the problem of intermediate frequency and high-frequency vibration of a complex system. The FE-SEA hybrid model and the SEA model of a ship are set up to solve the problem of intermediate frequency and high frequency vibration respectively. (2) a partial FE subsystem modeling method and a local mode parameter perturbation (LMP) method are proposed to improve the solution efficiency of the intermediate frequency problem. The method for solving the defects of the large-scale existence calculation efficiency is solved for the FE-SEA mixing method, only a part of the sub-system close to the vibration sound source cabin is selected to be described by using a determination method, and the other secondary part structures are described by a statistical method, And the coupling loss factor (CLFs) between the strong coupling structures is analyzed by the LMP method, and the accuracy of the simulation result is ensured under the condition of reducing the solution size of the intermediate frequency problem. (3) The contribution of the main vibration source of the engine room to the personnel's active cabin is determined. Based on the test data of the gantry and the real ship, the noise in the 200-8000 Hz frequency band is simulated, and the noise generated in the cabin by the vibration and radiation components of the main engine, the generator unit and the propeller are respectively calculated. The results show that the vibration component of the host and the generator set is the main source of the noise, and the components of the propeller can be ignored. (4) The transmission path of high-frequency vibration energy is proposed by using the graph theory algorithm. The high-frequency vibration system is equivalent to the energy transfer network under the graph theory frame: the SEA subsystem is considered as the node of the network graph, and the energy transfer weight between the nodes is obtained according to the loss factor to form the SEA-weighted directed graph. The main transmission path of high-frequency and high-frequency acoustic energy is obtained by using the deviation algorithm in graph theory to solve the K main path (KDP) with the largest weight of the source node to the target node. Finally, the importance of the node in the energy transfer is evaluated by the central measurement method, and the key structure plays a key role in the energy transfer. And (5) the selection method of the refined analytic object is refined, and the complexity of the path calculation is reduced. the concept of the vibration sound temperature is introduced, the temperature of the subsystem is calculated according to the energy, the mode number and the wave number of the subsystem, the one-way flow of the energy is determined, And the calculation scale is reduced. (6) The noise reduction scheme of a ship is established based on the medium-frequency and high-frequency vibration sound simulation and transmission path. A graph network is built on the whole ship simulation, and the KDP in the host and generator set to the target cabin is solved, and the structure and the coupling connection which play a main role in the energy measurement are determined by the central measurement. The results show that the maximum impact on the vibration is the input group and the path group node, corresponding to the bottom of the main engine room and the auxiliary engine compartment and the vertical bulkhead between them. The noise reduction and noise reduction measures are applied to the position of these critical nodes by using the vibration-resistant quality, which can reduce the noise of the generator set in the nearby people's living compartment by 5.59 dB (A). The research of this paper not only solves some of the problems existing in the FE-SEA hybrid method and the SEA method in the engineering application, but also provides a feasible solution for the solution of the high-frequency and high-frequency vibration transmission path. The application of graph theory in the energy transfer of complex system provides a clever solution for energy transfer and analysis in complex system, and quantifies the function of the local structure in the energy transfer of the system, and has obtained a series of conclusions with practical value. It is of reference value to the noise design of complex system such as ship.
【学位授予单位】：大连海事大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U661.44

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