风冷式冰箱风罩气腔气动噪声实验与仿真研究

发布时间：2018-06-16 16:46

本文选题：风冷式冰箱 + 气动噪声　；参考：《昆明理工大学》2017年硕士论文

【摘要】：风罩是风冷式冰箱风冷系统主要组成部分,在风冷式冰箱内部冷热气流的交换以及各个舱室之间温度调节过程中起着重要的作用,因此一般在设计风罩时往往仅考虑制冷效率与除霜效果,而忽视对其结构进行低噪设计。风罩的主要噪声有:离心风扇转动产生的气动噪声、流体在风道腔体内部流动而产生的气动噪声、风扇转动引起风罩壳体结构振动的噪声。因此风罩气动噪声的研究对于风罩的整体噪声研究具有重要意义。近些年,随着技术与理论的发展,关于空腔气动噪声的研究已经成为空气动力学科的一个热点。但目前大部分研究方向主要集中在亚音速或超音速气流条件下的气动简单结构腔噪声问题,对于一般的工业应用中,低速气流与结构复杂的腔体气动噪声问题则较少涉及,因此研究低速复杂结构腔体的气动噪声对于工业应用具有很大的意义与价值。本文以风冷式冰箱的冷凝风罩模型为研究对象,采用实验测试、结构动力学、计算流体动力学与计算气动声学仿真分析相结合的研究方法,研究冰箱冷凝风罩内部气腔气动噪声特性。研究内容主要包括:设计了将风冷式冰箱风罩与内部离心风扇分离的气动噪声特性测试试验台,通过试验台进行模态实验以及振动噪声的测量实验,测试风罩壳体模态参数与空腔气动噪声特性;采用计算流体动力学CFD与计算气动声学方法对风罩气腔模型进行流体动力学分析与噪声仿真分析,得到了风罩气腔的流场分布特征与声压频谱特征;噪声关键频率成分与仿真结果,较为吻合,然后分析风罩气腔的气动噪声特点以及影响因素,并讨论误差产生的原因。为下一步的风罩的减振降噪与结构优化提供理论与实验支持。通过对风罩气腔气动噪声进行研究分析,得出了冰箱风罩气腔内部气动噪声的组成及影响因素,提出了流体引起复杂腔体气动噪声的一种研究方法。
[Abstract]:The air hood is the main part of the air cooling system of the air-cooled refrigerator, which plays an important role in the exchange of the cold and hot airflow inside the air-cooled refrigerator and in the process of adjusting the temperature between the various compartments. Therefore, the cooling efficiency and defrosting effect are usually taken into account in the design of the wind cover, but the low noise design of the structure is neglected. The main noise of the wind cover is the aerodynamic noise caused by the centrifugal fan rotation, the aerodynamic noise caused by the fluid flowing in the air duct cavity, and the noise caused by the wind cover shell structure vibration caused by the fan rotation. Therefore, the study of the aerodynamic noise of the wind cover is of great significance to the study of the overall noise of the wind cover. In recent years, with the development of technology and theory, the research of cavity aerodynamic noise has become a hot topic in aerodynamics. However, at present, most of the research directions are mainly focused on the aerodynamic simple structural cavity noise problem under the condition of subsonic or supersonic flow. For general industrial applications, the aerodynamic noise problem of low speed airflow and complex cavity is less involved. Therefore, the study of aerodynamic noise of low speed complex cavity has great significance and value for industrial application. In this paper, the model of condensing wind cover of air-cooled refrigerator is taken as the research object, and the research method of combining experimental test, structural dynamics, computational fluid dynamics and aerodynamic acoustics simulation analysis is adopted. The aerodynamic noise characteristics of the air chamber inside the condensing hood of the refrigerator are studied. The main contents of the study are as follows: the pneumatic noise characteristic test bench is designed, which separates the air-cooled refrigerator air cover from the inner centrifugal fan, and carries on the modal experiment and the vibration noise measurement experiment through the test bed. The modal parameters of the shell and the aerodynamic noise characteristics of the cavity are tested, and the hydrodynamic analysis and noise simulation of the air-chamber model are carried out by CFD and aerodynamic acoustics. The characteristics of flow field distribution and sound pressure spectrum are obtained, and the key frequency components of noise are in good agreement with the simulation results. Then the aerodynamic noise characteristics of the chamber and the influencing factors are analyzed, and the causes of the errors are discussed. It provides theoretical and experimental support for the next wind cover vibration and noise reduction and structural optimization. Based on the research and analysis of the aerodynamic noise in the air chamber of the air hood, the composition and influencing factors of the aerodynamic noise in the air chamber of the refrigerator are obtained, and a research method for the aerodynamic noise caused by the fluid in the complex chamber is put forward.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM925.21

【参考文献】