某机载光电系统风冷散热翅片优化设计及仿真

针对机载密闭空间电子组件散热问题,对被动风冷翅片散热器进行了设计优化及仿真分析。首先基于正交实验设计方法以翅片厚度、翅片间距以及翅片高度为分析因素设计了三因素四水平正交实验;基于CFD数值仿真方法对不同翅片形式的散热器进行了仿真分析;最后基于极值分析对各因素对散热器散热性能的影响显著程度进行了分析。结果表明,翅片高度对散热器性能影响最大,翅片间距次之,翅片厚度影响最小,并得到了最优的翅片形式。     

大功率LED灯具散热器的优化设计研究

LED的散热性能对其寿命有至关重要的影响,而现阶段LED的散热器设计方法很多依靠的是经验值。本文针对这一问题,提出一种散热器的优化设计方法,该方法首先基于大量实验数据研究了散热器翅片单一因素（包括翅片高度、翅片间距、翅片厚度、底板厚度）对散热性能的影响,然后运用正交试验法,综合分析了各因素对散热性能的影响程度,最终得到了翅片参数的最优水平组合。最后本文利用此方法,设计了一款新的散热器,实验表明该LED灯源芯片温度降低,并计算了优化后翅片的效率。     

大功率 LED 散热器的数值模拟与优化

为解决大功率 LED 的散热问题,设计一种方形散热器,以传热理论为基础,采用基于有限单元法的数值计算方法,通过单一变量法对大功率 LED 采用空气冷却时的散热过程进行数值模拟,分析方形散热器结构参数对散热性能的影响规律并进行结构优化。研究结果表明：底板边长为 90 mm、底板厚度为 6 mm、翅片数量为 22 以及翅片高度为 50 mm 的方形散热器具有最佳的散热效果。     

半圆柱板翅片散热器传热特性的数值模拟

在板式翅片散热器的基础上,通过增加不同数量和半径的半圆柱肋片,构造了6种不同结构的半圆柱板翅片散热器(HPPFHS),并通过数值模拟的方法对这两种散热器的流动和传热特性进行了研究。结果表明,随着入口风速的增加,两种散热器的热阻减小的同时压降随之增大,但其热阻减小的趋势变小。入口风速相同时,相比板式翅片散热器,流经半圆柱板翅片散热器的空气受到半圆柱肋片的影响产生涡流,因而减少了热阻,同时增加了压降,但其综合性能远好于板式翅片散热器。     

LED投光灯叉翅散热器热分析及优化

为探究叉翅散热器在某100 W LED舞台投光灯上的散热强化作用并进行优化设计,通过数值模拟与实验验证的方法,对影响叉翅散热器散热性能的主要几何因素及其机理进行了分析。以LED芯片最高温度和散热器质量为优化目标,对短翅长度与间距进行了单因素分析,然后通过NSGA-Ⅱ算法进行双目标优化,并进行模糊C均值聚类,得到了不同应用场景下散热器配置。结果表明：叉翅散热器可有效增强散热性能,其结构可增加翅片表面平均对流换热系数,短翅长度和间距对单位质量散热性能影响均存在最优值,短翅过长或间距过小均会使翅片表面对流换热系数下降。双目标优化后的叉翅散热器可在几乎不改变散热器质量时,降低LED芯片最高温度2.33℃。     

大功率LED针翅式散热器散热性能数值模拟

发光二极管(LED)作为新一代光源,得到广泛应用.然而在工作过程中,大部分的电能会转变为热能,使LED的结温升高,可靠性降低.为了使LED芯片产生的热量能够及时有效地散发出去,通常采用翅片散热方法对其进行散热.采用数值模拟的方法对大功率LED针翅式散热器的散热性能进行了研究.为了验证模型的准确性,利用K型热电偶和安捷伦数据采集仪对散热器进行了实验测试.实验结果表明,该数值模型方程能够很好地模拟散热器的散热性能.此外,研究了大功率LED针翅式散热器的几何参数(翅片高度、半径、排数、列数)对LED散热性能(结温、对流换热系数和热阻)的影响,并且对翅片结构进行了优化分析.     

功率型LED灯散热器优化设计研究

针对大功率型LED路灯散热器稳态工作下温度中心集聚的热特性,利用有限元方法构建其3D模型,并在三维模型基础上得到散热器的稳态温度场分布云图;采用正交试验设计法探讨散热器中心翅片的厚度、底板的厚度、不同疏密程度结构对散热器的水平和垂直方向热传导的影响;最后根据实验结果得到能有效对LED路灯散热器温度进行热控制的优化参数和结构,该方案有效降低了散热器的最高温度并提高了散热器的垂直热传导能力;通过对实物进行实验测量得到温度数据再与有限元分析的温度场分布图比较,证明了设计仿真的准确性和可靠性。     

大功率LED 片式CO B光源散热设计

提出了大功率LED 片式CO B光源夹持式的散热方案。采用正交试验法分析了片式光源散热器的六个形状尺寸对片式CO B光源结温和成本（以散热器体积表征）的影响。采用极差分析法得出了不同散热器参数对片式CO B光源结温的影响程度大小为：翅片片数＞翅片高度＞翅片长度＞翅片厚度＞翅片间距＞基底厚度,对成本（散热器体积）的影响程度大小为：翅片片数＞翅片长度＞翅片厚度＞基底厚度＞翅片高度＞翅片间距。综合考虑光源结温和成本,得到15W 片式光源模组散热器的最优尺寸。提出在散热器基底中央位置加导热筋的散热方案对前片式光源模组存在的热集中现象进行了改进。根据“烟囱效应”,提出了在散热器中合理设计流道来增强片式CO B光源模组自然对流强度的方法。     

大功率LED路灯的散热结构设计和参数优化

为了达到对大功率LED路灯产品既降低制造成本(散热器质量)又加快散热的目的,优化了LED路灯散热器结构.在对原有结构参数化建模及热分析的基础上,采用正交试验分析了散热器中平板厚度、翅片厚度、翅片间距、翅片高度4因素对产品质童与散热效果的影响,并研究了同一结构下热传导与热对流两种方式对散热的影响,最终得出了一个较为理想的...     

大功率LED分段翅片散热器热设计

针对平板翅片式散热器存在的不足,提出一种分段翅片散热器。基于COMSOL Multiphysics平台,对不同分段数的分段翅片散热器的流动传热过程进行模拟。在此基础上,将Matlab模糊推理工具箱与Simulink相结合,对不同结构的散热器进行可靠性评估。最终得到分段数为4的散热器换热系数最大、可靠性最高、结构最佳,每段翅片长度、厚度、高度、翅片间距及分段间隔分别为29 mm,4 mm,40 mm,10 mm和3 mm。当入口风速由1 m/s增大到9 m/s,分段数为4翅片散热器的换热系数相对于平直翅片散热器提高了3.42%~5.47%,压降增大了31.60%~40.85%,可靠性提高了0.2。此研究为散热器结构的优化设计提供了理论依据和参考。     

影响功率器件散热器散热性能的几何因素分析

型材散热器的几何结构由肋片和基座构成，主要几何参数包括肋片长、肋片厚，肋片数、基座厚、基座宽等，研究了型材散热器几何因素对其热性能的影响，通过改变散热器的几何参数，可以有效的降低散热器的热阻，获得好的散热效果。本文的研究为型材散热器的的选择及优化设计提供了依据。     

高热流密度热沉散热能力数值仿真分析

固体激光器增益介质的热效应问题严重制约了高功率固体激光器的发展。本文从实际应用角度出发,通过数值仿真实验对比散热热沉的主要几何参数(包括热沉基底厚度、肋片高度、肋片宽度、肋片间距)对散热效果的影响;同时也分析了不同的外部流量条件下热沉的散热性能。计算结果表明:优化热沉几何参数,选取适宜的流量,热沉散热效果会有一定提升。     

肋片截面及安装角度对LED散热性能的影响

为提高LED的散热性能,研究了肋片截面形状及安装角度对LED散热性能的影响,获得了较优的肋片横截面形状和最佳肋片安装角度。首先,利用Matlab软件对矩形截面和三角形截面进行数值计算,选择具有较优截面形状的肋片制作3个实物模型;接着,通过温度场测试实验,对3种不同肋片安装角度的模型进行温度场分析,比较并利用Ansys仿真反求出各个模型的表面对流换热系数,进一步验证安装角度对LED散热性能的影响;最终获得较优的肋片截面形状为矩形,最佳安装角度为90°(即垂直于水平面)。     

A numerical study of the thermal performance of an impingement heat sink-fin shape optimization

This paper presents the results of a numerical analysis of the performance of an impingement heat sink designed for use with a specific blower as a single unit. These self-contained heat sink/blower units, which cause impingement type flow on the heat sink fins, are now commonly used for desktop microprocessors. One of the objectives of this study is to examine the effect of the shape of the heat sink fins, particularly near the center of the heat sink, on the thermal performance of the package. The pressure gradient at the center of the heat sink, near the base, tends to be high. It significantly reduces the airflow, and hence, transport in that region. Different fin shapes and airflow rates have been studied with the objective of searching for an optimal heat sink design that would improve the thermal performance without increasing the pressure drop across the heat sink. Parallel plate fins have been studied by removing fin material from the region near the center of the heat sink along the length and height of the fins. Seventeen different designs have been compared, and an "optimum" heat sink shape is reported that results in a lower operating temperature and pressure drop. It is found that removal of fin material from the central region of the heat sink enhances the thermal as well as hydraulic performance of the heat sink.     

LED筒灯复合结构热管散热器的数值模拟

为解决LED筒灯使用单纯自然对流散热扩散热阻过大、温度分布不均的问题,提出一种基于平板热管和热虹吸管的复合结构热管散热器,并用数值模拟的方法研究了热功率、翅片高度、翅片数目、辐射换热对该散热器性能的影响。模拟结果表明应用于LED筒灯的复合结构热管散热器的热阻随着热功率的增加而减小,翅片高度和翅片数目存在一个最优值,使得散热器温度和热阻最小,自然对流情况下不可忽视辐射换热的作用。     

Thermal design and optimization of natural convection polymer pin fin heat sinks

The design and optimization methodology of a thermally conductive polyphenylene sulphide (PPS) polymer staggered pin fin heat sink, for an advanced natural convection cooled microprocessor application, are described using existing analytical equations. The geometric dependence of heat dissipation and the relationships between the pin fin height, pin diameter, horizontal spacing, and pin fin density for a fixed base area and excess temperature are discussed. Experimental results of a pin finned thermally conductive PPS heat sink in natural convection indicate substantially high thermal performance. Numerical results substantiate analytical modeling results for heat sinks within the Aihara et al. fin density range. The cooling rates and coefficient of thermal performance, COP/sub T/, that relates cooling capability to the energy invested in the formation of the heat sink, has been determined for such heat sinks and compared with conventional aluminum heat sinks.     

A novel hybrid heat sink using phase change materials for transient thermal management of electronics

A hybrid heat sink concept which combines passive and active cooling approaches is proposed. The hybrid heat sink is essentially a plate fin heat sink with the tip immersed in a phase change material (PCM). The exposed area of the fins dissipates heat during periods when high convective cooling is available. When the air cooling is reduced, the heat is absorbed by the PCM. The governing conservation equations are solved using a finite-volume method on orthogonal, rectangular grids. An enthalpy method is used for modeling the melting/re-solidification phenomena. Results from the analysis elucidate the thermal performance of these hybrid heat sinks. The improved performance of the hybrid heat sink compared to a finned heat sink (without a PCM) under identical conditions, is quantified. In order to reduce the computational time and aid in preliminary design, a one-dimensional fin equation is formulated which accounts for the simultaneous convective heat transfer from the finned surface and melting of the PCM at the tip. The influence of the location, amount, and type of PCM, as well as the fin thickness on the thermal performance of the hybrid heat sink is investigated. Simple guidelines are developed for preliminary design of these heat sinks.     

散热器的电磁辐射和散热特性分析

利用Feko软件分析对比了两种集成电路散热器的电磁辐射特性,再用Flotherm软件分析了它们的散热特性。结果表明,散热器在某些频率产生较大辐射,针状散热器的辐射与片状散热器,在一定频率范围内差别不大,但针状散热器散热性能要好于片状散热器。     

Heat transfer from square pin-fin heat sinks using air impingement cooling

Experimental and numerical results are presented for heat transfer from a C4 mounted organic land grid array (OLGA) thermal test chip cooled by air impingement. Five heat sink geometries were investigated for Reynolds numbers ranging from 9,000 to 26,000. The dimensionless nozzle-to-heat sink vertical spacing z/D was varied between 2 and 12. In this study, we investigate the interactions between heat sink geometry, flow conditions and nozzle setting and how they affect the convective heat transfer and overall cooling of the test chip as measured by total thermal resistance /spl theta//sub ja/. Optimizing fin arrays by minimizing the overall heat sink thermal resistance instead of focusing solely on maximizing the heat transfer from the fins is shown to be a better design criterion. We also provide results that show cooling performance gains can be obtained by inserting a deflector plate above the heat sink.