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微尺度通道内流动沸腾研究综述 总被引:1,自引:0,他引:1
阐述了微尺度通道内传热问题出现的工程背景——高密度微电子器件的冷却。对当前国内外微尺度通道内流动沸腾换热特性的研究现状进行了归纳。突出分析了工质种类、微尺度通道的几何参数和工质的工况参数等对微尺度通道内流动沸腾换热特性的影响。同时分析了微尺度通道内流动沸腾换热的强化机理、流动阻力特性、压降关联式和沸腾换热关联式的理论和实验研究。最后根据分析对今后的工作提出了一些建议。 相似文献
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为了研究带有交错内肋微通道的流动和传热特性,采用数值模拟的方法分析了肋片的形状对微通道热力性能的影响,对比了矩形肋、菱形肋、三角形肋和圆形肋4种不同形状内肋结构的微通道和光滑矩形微通道的热力性能。结果表明:矩形肋、菱形肋、三角形肋和圆形肋微通道的努塞尔数Nu都大于光滑矩形微通道的努塞尔数Nu,最大值分别为光滑矩形微通道的2.59,2.71,2.90和2.48倍;肋片对微通道的传热特性具有显著的强化作用,这是由于流体在交错内肋的后方产生涡流,实现整个流场的全局强化传热,极大提升微通道传热特性;交错内肋的应用也增大了通道的摩擦系数,矩形肋、菱形肋、三角形肋和圆形肋微通道摩擦系数的最大值分别为光滑矩形微通道的8.66,7.96,17.50和5.96倍。 相似文献
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建立了非圆形硅微通道内单相流动和换热过程的三维模型,并分别对三角形、矩形和梯形微通道中流动换热进行了数值模拟.研究发现,截面平均努塞尔数在通道入口处数值最大,然后沿流体流动方向急剧减小,直至流动充分发展时趋于恒定.固体和流体温度沿流动方向近似线性升高.换热面壁温仅沿流动方向升高,在垂直于流动方向,温度则基本保持均衡;雷诺数对微通道的流动与换热特性存在着较大的影响,雷诺数越大,其对应的努塞尔数也越大.对3种微通道的热经济性分析比较发现,三角形通道的热有效性最高. 相似文献
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Flow and heat transfer characteristics of slot jets impingement to a cylindrical convex surface are numerically investigated.Suitable turbulence models have been determined through comparison with the experimental data.Flow structures are described and impingement heat transfer characteristics are discussed.The effects of Re,H/B and D/B on single-slot jets impingement heat transfer are analyzed and heat transfer characteristics of multiple-slot jets are investigated.The results show that:Gas flows along the convex surface and boundary layer separation occurs in both single and multiple-slot jets impingement.A maximum stagnation Nu appears at H/B=8 and the local Nu decreases with increasing H/B in the region far away from the stagnation.The Nu in the stagnation region decreases with increasing D/B but the Nu is nearly the same in the region far away from the stagnation.Pressure gradient is an important factor on heat transfer enhancement.Correlations of the Num for single-slot,double-slot and quadric-slot jets impinging on a convex surface are obtained.It indicates the effects of Re and D/B on Num could become more important in less slot jets impingement. 相似文献
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浇注系统的设计是铸造工艺设计的主要内容。利用数值模拟技术,可对浇注系统进行优化设计。建立了液态金属流动和传热的数学模型,讨论了边界条件、初始条件的选择,对液态金属浇注过程中的流动与传热耦合问题进行了数值模拟,并对模拟结果进行了讨论。所得结论对于浇注系统和过程的优化设计具有重要的实用价值。 相似文献
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为了深入挖掘三角翼纵向涡发生器在两个相对壁面布置的强化换热潜力,采用数值模拟方法,在雷诺数3 000~18 000的范围内研究了5种纵向涡发生器配置的流动换热情况,配置方式包括单面布置的共同上、下流配置,双面布置的共同上、下流配置,以及混合配置。结果表明:纵向涡可以很好地提高场协同效果,换热强度不完全取决于通道中的二次流强度,还取决于通道中的场协同性;在所有配置中,混合配置具有最高的二次流强度、最佳的场协同效果以及换热性能,可以将光滑通道的Nu提高28.3%~35.3%;另外4种配置可分别将光滑通道的Nu提高21.4%~32.0%,20.0%~29.2%,26.3%~34.3%和23.7%~28.0%;建议选用Re<6 000范围内的混合配置,此时其具有1.03~1.10的综合换热因子以及1.32~1.35的Nu/Nu0。 相似文献
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. oas-sous tw con~ tot ed trsmeans of meving Pactri tal bo bo widsly nsed intw ot wet boal. ~ or not od,mp Of gaS aDd solid waSte hot and otherinMal tw. W bas the adVantage Of bo bedpem tw, cope edgUhaOn anu easr cootOf -al reshaCe tim diStritw (RTD in hedexChaDg over the fhadhal bo mfor. HOWeVer uP tohaX the -- on the hod transfer in thes kindOf bea tw are od feW to our We.McGa wt a two -ed hamch COnSistw Of pe -- l,], in which themoha ~ We was divital into man diotch an0 the bo o… 相似文献
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Hideki Yanaoka Takao Inamura Yosuke Suenaga Daisuke Sugimoto Yasuo Kobayashi 《亚洲传热研究》2008,37(8):471-484
Three‐dimensional numerical simulations of asymmetrical flows and heat transfer around a hill in shear flows were performed. When shear velocity distributions are introduced at the inlet, a vortex pair is formed asymmetrically to the spanwise direction behind the hill. Further, an asymmetrical hairpin vortex is periodically generated downstream. The leg of the asymmetrical hairpin vortex on the high‐speed side collapses first. Further downstream, the asymmetrical hairpin vortex breaks down earlier than the symmetrical hairpin vortex, and streamwise vortices appear on the high‐speed side. These streamwise vortices increase the heat transfer downstream. In contrast, no hairpin vortex appears in the case of a strong shear velocity distribution, but instead a streamwise vortex appears. The heat transfer decreases downstream since the turbulence generated by streamwise vortices is weak. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20223 相似文献