基于流固声耦合的空间管路系统振动噪声研究及在空调配管的应用

The problem of vibration and noise is conspicuous increasingly. Based on the characteristic of vibration and noise of spatial pipeline system, the applicant makes theoretical study coupled by acoustic field of medium in pipe and vibration and noise of pipe with fluid-structure interaction, by which the vibration and noise of pipeline system can be reduced to a very low lever in design stage. Considering pressure fluctuation of airflow as coupling agent, a fluid-structure coupling model can be constructed of spatial pipeline system,and vibration equation of the medium in pipe is built by the wave theory. Then the fluid-structure acoustic coupled mathematical model is built by correlating the above models. Further analytical solutions of the model are obtained by transfer matrix method with Laplace Transform and Fourier Transform. On this basis, low-frequency vibration and noise are studied of the pipeline system in air-conditioner. And the NVH performance of all components in pipeline system and its propagation law are analysed. Then the source, generation mechanism and transmission path of low-frequency noise can be researched, and contributions to low-frequency noise can be obtained of each component in the air-conditioner pipes. Finally, experiment study on the air-conditioner ptototype is done in order to verify rationality of the theoretical model. So the research results of this project can lay a theoretical foundation for optimization design on pipeline system and low-frequency noise control or elimination of the air-conditioner pipes fundamentally, which has important theoretical significance and application value.

针对当前日益突显的振动噪声问题，申请人根据空间复杂管路的振动噪声特点，提出将管路的流固耦合振动噪声与管路内介质的声场相耦合的方法进行理论研究，从而在设计阶段就把管路系统的振动噪声降到较低水平。项目以气流的压力脉动为主要耦合剂，建立空间管路系统的流固耦合模型，并根据波动理论建立管路内介质的振动方程，然后将两者进行联立，建立管路系统流-固-声耦合的数学模型。拟采用Laplace变换和Fourier变换推导系统的传递矩阵，并推导解析解。在此基础上，结合空调的配管系统，采用建立的理论模型对管路的低频振动噪声进行研究，分析管路中各部分的振动噪声特性及其传播规律，研究空调管路中低频噪声产生的根源、机理、传递路径及各部分对低频噪声的贡献量。最后通过实验对理论模型进行验证。本项目的成功实施将为空调管路系统的优化设计及从根本上控制或消除空调管路的低频噪声等奠定理论基础，具有重要的理论意义和实用价值。

管路系统是当今输送流体的最重要设备之一，而且应用非常广泛，近年来关于管路的振动噪声问题备受关注。本项目根据空间复杂管路的振动噪声特点，借助于流固耦合基本理论，建立了典型管段的流固耦合模型，并进行动态响应分析，初步给出空调中振动噪声的传递路径；同时项目探索了管路中压力脉动变化规律及其对管路动态响应的影响机理，初步揭示了流固耦合作用对管路的动态响应的影响规律，获取了一些隔音材料的隔音特性和管路的减振降噪方法，从而为管路的优化设计和减振降噪提供参考依据。