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针对电子器件的散热问题,设计了6种渐缩型微通道,并通过合理布置圆形凹穴来削减截面几何尺寸突变导致的压力损失。旨在借助凹穴结构促进微通道冷却液混合提升换热性能,以及通过优化通道几何尺寸来改善微通道的流体流速分布,从而进一步提升微通道换热性能。在高热流密度条件下,对6种带凹穴渐缩微通道和普通矩形微通道的流动换热特性进行了对比数值分析,并以泵功和热阻为评价指标来评价通道综合传热性能。结果表明:通过设置渐缩微通道凹槽及通道截面的合理分布,改善了流速的分布,使温度分布更加均匀,并且增强了其散热能力。在实验组的最优结构下,渐缩微通道热阻比普通矩形微通道降低了18.4%,综合传热性能最高提升了15.2%。 相似文献
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针对变频器发热的问题,提出一种S型微通道散热模块,并对其传热性能进行了理论分析,推导得出热阻与结构参数的数学关系式。利用Fluent软件,对S型微通道散热模块的结构参数进行优化,分析其对散热性能的影响,并进行了实验验证。研究结果表明,S型微通道散热模块可有效提升变频器的散热性能,较优的结构参数为:流道水力直径为1.4 mm、流道宽高比为3∶1、弯曲曲率半径为30 mm。将S型微通道散热模块与铜圆管铸铝散热模块进行了仿真及实验比较,结果表明前者基体平均温度比后者要低2.3℃,热阻降低了20.38%,说明S型微通道散热模块具有较好的散热性能。 相似文献
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三维集成电路(3D IC)由于其高热密度,给其热管理带来了巨大挑战。微通道热沉因结构紧凑、散热能力突出,是解决三维集成电路散热问题的有效途径。本文以三维集成电路单层不同形状的横截面的微通道热沉为研究对象,利用计算流体动力学(CFD)方法对三维集成电路单层不同形状的横截面的微通道的热特性进行数值仿真分析。实验结果表明,不同形状的横截面的微通道,有着不同的散热性能,针对矩形横截面的微通道和圆形横截面的微通道进行比较,矩形横截面的微通道有着更好的散热性能。 相似文献
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基于连续性方程和N-S方程,建立了油液在102μm量级通道中流动的数学模型,利用有限元法求得了速度的数值解,并利用CFD软件Fluent分别数值模拟了进口段效应、几何结构参数和重力效应对光滑矩形截面微通道中油液流动特性的影响。结果表明:油液在微通道横截面上的速度分布近似呈抛物线型分布,最大流速在微通道的中心轴线处;进口段效应对油液微流动的影响在通道长度较大时可以忽略;微通道内油液低雷诺数流动的阻力系数随长径比增大而减小,长径比大于75时趋于稳定,而摩擦阻力常数则随高宽比的增大而呈指数级增大;重力效应对油液的微流动可以忽略不计。 相似文献
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为了提高大功率激光二极管列阵的散热效率以便提高其寿命和波长稳定性,研制了一种封装集成度较高的屋脊式硅基微通道热沉.将田口稳健设计方法用于微通道热沉的优化设计,利用正交试验和信噪比分析实现了参数的稳健优化.以(110)单晶硅作为基片,采用KOH各向异性刻蚀和硅-玻璃-硅三层阳极键合方法制作出了通道宽度约为50 μm的微通道热沉,通道壁面粗糙度优于0.1 μm.采用激光二极管芯片对样品进行了封装和测试,利用砷化镓激光波长的温度漂移系数估算出了中间激光二极管的有源区温升,从而计算出了热沉的热阻.测试结果表明,该微通道热沉的单位面积热阻约为0.070 cm2·K/W,与有限元分析结果基本一致. 相似文献
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在恒定泵功0.05 W条件下,对水冷铜基和铝基微通道热沉对流换热进行详细数值模拟和结构优化。通过将数值预测结果与前人已发表的试验结果进行对比,验证所使用的数值模型的正确性。同时讨论在恒定泵功下微通道几何结构对微通道热沉中温度分布的影响。模拟结果显示水冷铜基微通道热沉最优的几何结构参数为通道深为580μm,通道宽为90μm,通道密度为100个/cm;铝基微通道热沉最优的几何结构参数为通道深为620μm,通道宽为80μm,通道密度为100个/cm。 相似文献
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将田口稳健设计方法用于面向大功率激光二极管列阵的硅基屋脊式微通道热沉的优化设计,利用正交试验和信噪比分析实现了参数的稳健优化。采用激光二极管条对样品进行了封装和测试。利用砷化镓激光波长的温度漂移系数估算出了中间的激光二极管条的有源区温升。测试结果表明,该微通道热沉的单位面积热阻约为0.070 K8226;cm2/W,与有限元分析结果基本一致。 相似文献
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Yong H Kim Woo Chong Chun Jin Taek Kim Bock Choon Pak Byoung Joon Baek 《Journal of Mechanical Science and Technology》1998,12(4):709-718
A study of manifold microchannel (MMC) heat sinks for forced air cooling was performed experimentally. The manifold microchannel
heat sink differs from a traditional microchannel (TMC) heat sink in that the flow length is greatly reduced to a small fraction
of the total length of the heat sink. In other words, the MMC heat sink features many inlet and outlet channels, alternating
at a periodic distance along the length of the microchannels while the TMC heat sink features one inlet and one outlet channels.
The present study primarily focused to investigate the effects of geometrical parameters on the thermal performance of the
manifold microchannel heat sinks for optimal design. Also, the thermal resistances of the MMC heat sinks were compared with
those of the TMC heat sinks. Experimental results showed the thermal resistances of MMC heat sinks were affected strongly
by the pumping power, the microchannel width and the manifold inlet/outlet channel width, but weakly by the microchannel thickness-width
ratio and the microchannel depth coorporated with the manifold inlet/outlet channel width. However, it was found that there
existed the optimum values of the latter parameters. Under the optimum condition of geometrical parameters in the present
study, the thermal resistance of the MMC heat sink was approximately 35% lower than that of a TMC heat sink, which clearly
demonstrated the effectiveness of using a manifold. 相似文献
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The present study describes the fabrication of a novel microchannel with 60 electrodes and the electrical resistance measurement in different flow types in the microchannel system. This microchannel is designed for ERT application, which has five measurement cross sections and embeds 12 electrodes in each cross section. The microchannel has been successfully fabricated by MEMS processes which are comprised of photolithography of platinum wire on quartz glass layers, compression to fabricate the electrode layers, and micro mechanical processing for the flow groove. After the microchannel fabrication, the connector is constructed in order to avoid unstable measurement condition between the microchannel electrodes and the resistance measurement system. The electrical resistances between the electrode pairs of the microchannel were measured in the case of tap water, particle flow and the separately injected tap water plus particle flow. The electrical resistances are reasonably and stably measured in the microchannel. 相似文献
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将微管道换热器抽象成多孔介质模型,由Brinkman-extended Darcy方程出发,分别按照双方程模型和单方程模型进行求解,以得到微管道内流体的速度场和温度场分布,并对单方程模型和双方程模型的解析解进行了对比,讨论了微管道高宽比和有效导热系数比对流动与传热的影响。证明了由基于多孔介质双方程、单方程模型所得的解析解均可用于预测微管道换热器中的容积平均速度与温度分布。利用基于多孔介质双方程模型还可得出微管道换热器的总热阻和优化设计结构,结合硅衬底上的多路感应耦合等离子体刻蚀工艺加工出了经结构优化的硅制微管道换热器。在满足局部热平衡条件下,基于多孔介质单方程模型更适用于实际工程计算,不必经由预先的试验确定换热系数。 相似文献
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针对飞行器大功率电动舵机伺服系统功率模块内各器件发热损耗不同引起温度不均的问题,开展非均匀热流下微小通道热沉传热特性分析。依据功率模块三相桥电路的实际构型和工作特点,在数值计算方法和网格无关性验证基础上,利用FLUENT建立多种结构微小通道热沉的数值模型,对冷却通道在高、低热流区的典型周向传热特性及热沉总体性能进行探讨。研究发现,相同通道截面下,各通道圆周方向壁温呈非均匀分布,但不同通道的相同位置处局部传热系数较为一致;对于等流通面积的变截面冷却通道,通道数量及结构对局部传热影响突出。非均匀热流分布和通道流向、通道构型相匹配有助于改善基底均温性,渐缩通道构型和小截面多通道构型强化传热优势明显,具有较低热阻和较好均温性。 相似文献
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Xu Shanglong Hu Guangxin Qin Jie Yang Yue 《Journal of Mechanical Science and Technology》2012,26(4):1257-1263
Four different microchannel heat sinks are designed to study the effects of structures in microchannel heat sinks for electronic
chips cooling. Based on the theoretic analysis and numerical computation of flow and heat exchange characteristics, the electronic
chip’s temperature and flow rate distributions are obtained. The correspondence between flow pressure drop and chip’s temperature
in the four microchannel heat sinks is also studied and analyzed. Numerically analyzed results indicate that the topological
structure in microchannel heat sink has a significant influence on electronic chips cooling. This study shows various thermal
properties in the four microchannel heat sinks. 相似文献
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Yoon Jo Kim Yogendra K. Joshi Andrei G. Fedorov 《Journal of Mechanical Science and Technology》2008,22(2):338-349
Theoretical analysis and simulation of performance of an air-cooled microchannel absorber is reported in this study. It is
shown that the air-cooled microchannel absorber can be integrated into an absorption-based miniature electronics cooling system
by which the chip junction temperature can be maintained near room temperature, while removing 100 W of heat load. Water/LiBr
pair is used as the working fluid and refrigerant vapor is intended to counter-currently flow against aqueous LiBr solution
flow. Parametric study is carried out to determine the effects of several operating parameters, including inlet temperature
and mass flow rate of the coolant, and inlet temperature of LiBr solution. To facilitate the air-cooling of microchannel absorber,
an offset-strip-fin array is adopted, by which enhanced air-side heat transfer coefficient and large heat transfer area are
obtained. The performance of the air-cooled absorber is compared to liquid-cooled absorber. 相似文献
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