摘 要:汽车散热器是车的重要附件，是水冷式内燃机冷却系统中不可缺少的一个组成部 分，它的正常工作，保证了发动机乃至整个汽车的工作效率和可靠性。因此，散热器 的正确设计对汽车的正常运行至关重要。本文主要论述汽车散热器阻力特性分析。
本文首先对本课题的背景与意义和汽车散热器的发展形势进行了叙述，阐明了研 究本课题的目的和工程价值；然后对汽车散热器结构进行了概述，着重介绍了汽车散 热器数值计算基础---CFD 理论，为下面对散热器进行 CFD 分析做好了必要的准 备；接着构建了汽车散热器的几何模型及其网格的划分，最后在此基础上对散 热器进行 CFD 分析，得出压降曲，经计算结果验证计算精度达到了工程要求。
经上述过程可以得出：压力沿着百叶窗流动方向基本呈线性关系递减，流动单元
前半部分压降略小于后半部分的压降；空气在百叶窗汽车散热器内部流动，在低雷诺 数时，空气以轴向流动为主；高雷诺数时，以百叶窗翅片间流动为主，增加了流动效 率；随着迎面风速的增加，百叶窗汽车散热器空气流动阻力(散热器进出口压力差) 变化明显，空气流动阻力随着迎面风速的增加而成抛物线增加，增加的幅度越来越大。
本文的研究结果经验证达到工程要求，可以将此应用于汽车散热器空气流动特性 分析中，为车辆总体设计和发动机舱内流阻力计算提供参考数据，同时为散热器的优 化提出参考性的意见，以较大降低实验设计费用，缩短设计周期，具有较好的工程应 用价值。
关键词：散热器，阻力特性，CFD 分析
Abstract:Radiator is an important vehicle accessories, is water-cooled internal combustion engine cooling system, an indispensable component of its work to ensure that the engine and the whole vehicle efficiency and reliability. Therefore, the correct heat sink design is essential to the normal operation of motor vehicles. This article discusses the resistance characteristics of automotive radiators.
This paper first the background and significance of this issue and developments in automobile radiators of the narrative in the study of this topic to clarify the purpose and value engineering; and then an overview of the structure of car radiator, car radiator highlighted numerical basis - - CFD theory, for the following CFD analysis on the radiator to make the necessary preparations; then build the geometric model of the vehicle radiator and grid division, the last radiator in this based on CFD analysis were obtained pressure drop curve, calculated by the calculation results show the accuracy of the engineering requirements.
The above process can be drawn: the pressure along the flow direction and shutter a linear relationship between decreasing the pressure drop of flow unit slightly smaller than the first half of the latter part of the pressure drop; air in the radiator shutters internal flow at low Reynolds number of air to the main axial flow; high Reynolds number, to flow between the main shutter fin to increase the flow efficiency; with the face velocity increases, blinds car radiator air flow resistance (pressure radiator Import and Export SD) changed significantly, with the face velocity of air flow resistance to the increase of the parabolic increase in the rate of increase is increasing.
This study validated achieve the required results can be applied to this air flow characteristics of automotive radiators in the engine compartment for the vehicle design and provide reference data for calculation of flow resistance, and put forward recommendations for the optimization of the radiator of views to reduce the large experimental design cost and shorten the design cycle, and has good value in engineering.
Keywords: radiator, resistance, CFD analysis
