【作者】 艾奇；

【导师】 上官文斌； 叶志刚；

【作者基本信息】 华南理工大学 ， 机械工程， 2010， 硕士

【摘要】 轴流风扇叶轮的基本参数如轮毂比、叶片安装角、叶片弯掠角与弦长,风扇与散热片之间的距离等,对微型计算机CPU散热器的散热效能、噪声大小及声音品质起着至关重要的作用。本文在运用二次正交试验设计的基础上,提出了微型计算机CPU散热器中轴流风扇与散热片的协同设计方法。该方法是将影响散热效能与噪声的7个可能因子进行一次正交试验设计,得到影响散热效能与噪声大小的3个主要因子;再将这3个主要因子进行二次正交试验设计,最终获得优化方案。本次研究为了保证仿真精度,采用全流道计算,划分四面体与六面体混合网格,计算网格约150万。在获得高精度仿真结果及试验测试结果的基础上,运用统计方法对仿真与试验数据建立回归方程并进行分析。通过建立与散热效能及噪声的相关关系矩阵,找到与热阻及噪声有明显相关性的评价参数,同时也找到了热阻与噪声之间的关系。最后,基于优化结果及相关性分析,得到具有普遍意义的结论。散热片上端面通过流量与热阻呈明显负相关,即流量越大,热阻越小。声压值与最外和最内圆柱面的全压差值有明显的正相关性,与半径方向的单位全压值有明显的正相关性——即沿半径方向的全压差或单位全压值越大,则声压值越大。对于声音品质中的调制,推荐叶片的叶根与叶尖安装角均取较大值,而叶片弯掠角趋向于0°;对于突出比,推荐叶片的叶根安装角取较小值,叶尖安装角取较大值,叶片弯掠角取负值。这些具有普遍意义的结果,对此类产品的设计开发具有指导性意义。更多还原

【Abstract】 The basic parameters of axial fan impeller, such as boss ratio, blade angle, skewed-swept angle of blade and chord length, and the distance between fan frame and heat sink etc. obviously influence the thermal conductivity, acoustic noise and sound quality. This paper presents Synergistic Design Method for CPU cooler consisting of axial fan and heat sink based on second Orthogonal Experimental Design. In order to obtain optimized solution, to drive first orthogonal experimental design based on 7 potential factors influencing thermal conductivity and acoustic noise, and obtain 3 key factors to drive second orthogonal experimental design.In this research, model of full calculating zone is created, generating about 1,500,000 mixed meshes of Tetra and Hexa in order to obtain better precision. Based on the simulation and measurement results, statistics method is used to analyze the data and the marginal means is obtained to create the regression table. At the same time, the correlation matrix of the thermal conductivity and acoustic noise is created and the correlations of the estimation parameters between the thermal conductivity and acoustic noise, including correlation between the thermal conductivity and acoustic noise, are presented.Finally, the universal significance results based on the correlation analysis are obtained. There is distinct negative correlation between the thermal conductivity and flowrate through the upper section of heat sink. That means the thermal conductivity will be higher when the flowrate is on larger magnitude.?There is distinct correlation between sound pressure level and difference of total pressure of out columnar section and inner columnar section. There is distinct correlation between sound pressure level and total pressure per unit length. That means the sound pressure level will be higher when the difference of total pressure or the total pressure per unit length is on higher level. For modulation, the recommendations are the blade angle of hub and tip both on larger magnitude, but the skewed-swept angle of blade on 0 degree. For prominence ratio, the recommendations are the blade angle of hub on smaller magnitude, the blade angle of tip on larger magnitude, but the skewed-swept angle of blade on negative magnitude. These universal significance results are useful for similar product research and development.更多还原