共查询到17条相似文献,搜索用时 359 毫秒
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本文利用基于复合网格系统的计算方法,对Re=50~1200的近壁插入圆柱流场进行数值模拟,研究过渡流状态下在壁面附近插入圆柱对下游壁面传热强化的影响。并基于低速循环水槽流动实验台,采用粒子成像测试法(PIV)对Re=100~500的近壁插入圆柱流场进行可视化实验研究,验证了数值模拟方法的可靠性。研究结果表明:近壁插入圆柱流场在Re=100时进入过渡流状态;Re直接影响圆柱尾流中周期性涡脱和壁面涡岛的发生位置及其洗刷效应的大小,随着Re的增大,洗刷效应明显增强,因而,过渡流范围内Re越大,圆柱下游壁面传热强化越大。 相似文献
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竖直圆管中超临界压力CO2对流换热实验研究 总被引:5,自引:1,他引:4
本文对超临界压力CO2在竖直加热圆管内的对流换热进行了实验研究,比较了不同流向、不同热流密度等对流动和换热的影响。实验结果表明,管内径为2mm时,在低进口Re条件下,由于浮升力影响导致层流向湍流提前转变, 对流换热增强;与向上流动相比,向下流动更易由层流转变为湍流;向下流动的换热要强于向上流动,表明浮升力对换热有很大影响。对于管内径为0.27 mm的微细圆管,当进口Re高于104时,浮升力的影响可以忽略,对流换热系数的变化完全由物性的变化尤其是cp的变化导致。 相似文献
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Kanzawa A. Pfender E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1978,6(1):33-42
The application of thermal plasmas particularly in the field of plasma chemistry and plasma material processing requires a basic understanding of the heat transfer process. This paper is concerned with an analysis of the heat transfer to a positively biased body exposed to a plasma flow. Because of the induced current flow due to the biasing potential, the plasma surrounding the biased body will experience an increase in temperature caused by Joule heating. The fraction ? of the dissipated heat which is transferred to the body is calculated for an atmospheric argon plasma flow at temperatures between 104 and 2 × 104K and Reynolds numbers of 40 and zero. The results indicate that ? increases with increasing plasma temperature for Re = 40 and decreases slightly with increasing plasma temperature for Re = 0. As the Re number increases at constant plasma temperature ? decreases. 相似文献