【作者】 张红辉；

【导师】 邓兆祥；

【作者基本信息】 重庆大学 ， 动力机械及工程， 2002， 硕士

【摘要】 汽车产业的发展给人们带来了巨大的便利，同时，它所产生的排放、噪声和能源短缺问题也日益引起人们的关注。汽车的冷却风扇作为汽车的一个重要的噪声源，它的低噪声气动性能设计随着新的噪声法规的出台变得日益迫切。本文着眼于汽车冷却风扇的低噪声气动性能，从汽车冷却风扇的流体动力学理论和气动噪声的产生机理出发，建立数学模型，分析风扇主要结构参数对冷却风扇噪声性能的影响。根据叶轮机械设计中的正问题的提法，编制了计算机结构参数计算程序，进行了冷却风扇的设计计算，从若干种风扇设计方案中选优，进行三维实体造型，制造了快速原型模型用于噪声气动性能试验。同时，根据叶轮机械设计中的反问题的提法，针对发动机轴流冷却风扇的噪声性能，编制了反算程序，用于预测估计冷却风扇的噪声性能，从而为设计效果的验证提供初步依据。设计制造了发动机冷却风扇噪声性能测试专用试验台，用于冷却风扇的台架试验。同时，使用新的风扇原型进行了整车车外加速噪声性能测试。风扇台架试验测试结果表明，针对研究车型（SC6331B）改进设计的冷却风扇，噪声得到较大幅度的下降，在发动机主要工作转速下，风扇噪声下降3~4.5dB(A)，由此带来了1.5~2dB(A)左右的整车车外加速噪声的下降。配合护风圈的改进和冷却风扇相对护风圈安装位置的优化，整车车外加速噪声可以期待更大的降低，但限于试验条件的制约，未能得到有效地证实。由于计算流体力学和计算技术的迅速发展，利用数值技术进行流体机械正问题研究已经较为成熟，并有一定的研究与应用，但湍流模型尚待进一步完善。由于资金缺乏和技术意识的落后，国内的数值计算工作开展不够。为了探讨现代设计方法在冷却风扇设计中的应用，本文对冷却风扇的计算流体动力学问题（CFD）作了一定的探讨，同时，也对计算声学（CAA）的理论与实践作了一定的摸索。更多还原

【Abstract】 The great convenience has been brought to humans by the development of automobile industry, at the same time, the resulted exhaust and noise pollution and the shortage of energy source raised the comprehensive concentration. Cooling fan as an important noise source of automobile, its low noise aerodynamic performance design has been increasingly important with the issue of new noise regulation.This paper aimed at the low noise aerodynamic performance of automobile cooling fan, set out from the fluid dynamics and the mechanism of noise generation and radiation, mathematical model has been erected to analyze the influence of the main structural parameters on noise performance. According to the forward problem of impeller machinery design, calculation software was developed to get the main structure parameters of cooling fan, and optimum design schemes was selected from the many alternatives to manufacture the rapid prototyping model for the experiment. At the same time, according to the reverse problem of impeller machinery design, focusing on the noise performance, the counter calculation software was developed to estimate the noise of cooling fan to provide the elementary verification of the design effect.A specialized noise test bench of automobile cooling fan was designed to carry out the bench test and the outer vehicle acceleration noise test also was conducted. The bench test indicated that noise of the designed cooling fan was apparently decreased. At the important revolution, 3~4.5dB(A) noise decrease can be expected in the bench test and 1.5~2dB(A) decrease in the acceleration noise test. With the modification of shroud, a better result can be expected. But it was not verified by the limit of experiment condition.With the rapid development of numerical technology and CFD simulation, the numerical technology for the forward problem of impeller machinery design had a good investigation and application, but the turbulence model need to be improved. For the lack of fund and the lagging behind of the technological consciousness, the job was insufficiently conducted domestically. In order to exploit the application of modern design method to fan design, this paper discussed the CFD calculation and groped the theory and practice of CAA.更多还原