A级汽车暖通空调系统流动噪声分析

发布时间：2018-03-19 10:33

本文选题：汽车空调　切入点：HVAC系统　出处：《吉林大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着人民生活水平的不断提高,人们对乘车舒适性的追求也越来越迫切,汽车的噪声问题开始受到人们的重视。过高的车内噪声不仅影响车内人员的正常交流,还会引起车内人员的疲劳,甚至影响着行车安全,给人们的生命财产安全造成威胁,如何降低车内噪声成了近年来的关注问题。随着车外噪声的降低,以及车身密闭性的提高,空调HVAC系统的气动噪声成为了车内噪声的主要噪声源。改善HVAC系统的气动噪声特性的意义重大。汽车空调HVAC系统的气动噪声主要有风机噪声和风道噪声。对于风机噪声,很多学者针对风机的叶形、叶片数量、蜗舌间隙、蜗壳型线等结构参数进行了研究,改善了风机的气动噪声特性;通过减少风道结构上的突变,以降低风道内的压降,来改善风道的气动噪声特性。本文将HVAC总成作为研究对象,侧重分析总成内部结构对气动噪声特性的影响,并进行相应的优化,改善气动噪声特性。本文具体的研究内容为:对HVAC总成进行风量试验和噪声试验,获得总成在不同风机转速下的风量值和噪声值。通过对HVAC系统进行风机的阶次分析和出风口处的噪声频谱分析,对比两种噪声源噪声特性的区别,并为仿真分析提供边界条件。通过分析流场和声场的基本理论,建立HVAC系统的三维实体数模、湍流分析模型和声学分析模型。对总成的流场和声场进行仿真分析,并将风量值和噪声值与试验结果进行对比,对仿真模型的准确性进行验证。分析HVAC总成的流场和声场分布,获得总成内部的流场分布和噪声源分布情况,并通过分析出风口处的噪声频谱,对不同噪声源的噪声特性进行了对比。针对HVAC系统流场和声场的分析结果,对HVAC总成的气动噪声特性进行优化。首先,使用响应面法进行优化,采用两种优化机理对HVAC总成进行了多目标优化,建立了流量、压降和声压级与吹面、吹脚、冷暖风门的开角之间的数学函数关系,在不降低HVAC总成流场特性的前提下降低了出风口处的气动噪声,且两种优化结果基本相同。然后,通过添加导流板的方法对HVAC总成进行结构改进,降低了出风口处的气动噪声,效果相对多目标优化法不明显。最后,对三种优化方案的过程、结果进行综合对比,为HVAC系统的设计与优化提供了思路。
[Abstract]:With the continuous improvement of people's living standard, people's pursuit of ride comfort is becoming more and more urgent. It can also cause fatigue of the people in the vehicle, even affect the safety of driving, and threaten the safety of people's life and property. How to reduce the noise inside the vehicle has become a concern in recent years. With the decrease of the noise outside the vehicle and the improvement of the airtight of the car body, The aerodynamic noise of air conditioning HVAC system has become the main noise source of vehicle interior noise. It is of great significance to improve the aerodynamic noise characteristics of HVAC system. The aerodynamic noise of automobile air conditioning HVAC system mainly includes fan noise and air duct noise. Many scholars have studied the structural parameters of the fan, such as leaf shape, number of blades, cochlear tongue clearance, volute line and so on, to improve the aerodynamic noise characteristics of the fan, and to reduce the pressure drop in the duct by reducing the abrupt change in the air duct structure. In this paper, the HVAC assembly is taken as the research object, the influence of the inner structure of the assembly on the aerodynamic noise characteristics is analyzed, and the corresponding optimization is carried out. The main contents of this paper are as follows: air volume test and noise test for HVAC assembly. The wind volume and noise value of the assembly at different fan speeds are obtained. By analyzing the order of the fan and the noise spectrum at the outlet of the HVAC system, the differences between the noise characteristics of the two kinds of noise sources are compared. By analyzing the basic theory of flow field and sound field, the three-dimensional solid mathematical model, turbulence analysis model and acoustic analysis model of HVAC system are established. The flow field and sound field of the assembly are simulated and analyzed. The accuracy of the simulation model is verified by comparing the wind value and the noise value with the experimental results. The flow field and sound field distribution of the HVAC assembly are analyzed, and the distribution of the flow field and the noise source inside the assembly is obtained. By analyzing the noise spectrum of the air outlet, the noise characteristics of different noise sources are compared. The aerodynamic noise characteristics of the HVAC assembly are optimized according to the analysis results of the flow field and sound field of the HVAC system. The response surface method is used to optimize the HVAC assembly with two optimization mechanisms, and the mathematical function relationship between the flow rate, pressure drop and sound pressure level and the opening angle of the blowing surface, blowing foot, cold and warm air valve is established. The aerodynamic noise at the air outlet is reduced without reducing the flow field characteristics of the HVAC assembly, and the two optimization results are basically the same. Then, the structure of the HVAC assembly is improved by adding the guide plate, and the aerodynamic noise at the air outlet is reduced. The result of the method is not obvious. Finally, the results of the three optimization schemes are compared synthetically, which provides the train of thought for the design and optimization of HVAC system.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.851

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