Experimental research on natural convective heat transfer of water near its density maximum in a horizontal annulus
Experimental research on natural convective heat transfer of water near its density maximum in a horizontal annulus
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水平环空密度极大值附近水自然对流换热实验研究
DOI：
10.1016/j.expthermflusci.2012.08.016
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发表时间：
2013
影响因子：
3.2
通讯作者：
Jing-Wen Tang
中科院分区：
文献类型：
--
作者：
You-Rong Li;Xiao-Feng Yuan;Yu-Peng Hu;Jing-Wen Tang
本文对水在水平环隙内密度极大值附近的自然对流换热特性进行了实验研究。环由两个同心或偏心的铜圆柱形壁形成。外筒的温度保持在0°C左右，内筒的温度范围为0至12°C。为了强化传热，在内壁上应用了三维外翅片。研究了环隙差距、环隙偏心率和肋片几何参数对换热的影响。结果表明，内壁平均努塞尔数的两个转折点分别出现在温差接近4°C和8°C时。随着温差的增大，平均努塞尔数先增大，然后减小，最后又增大。平均努塞尔数的最小值位于温差8°C附近。此外，随着环隙差距宽度和偏心距的增大，偏心距也增大。此外，当应用三维外翅片时，平均努塞尔数随着翅片轴向间距的增加而增加，而随着翅片宽度的增加而减小。在实验值范围内，翅片高度和间距对螺旋桨性能的影响很小。最后，得到了管内壁面换热的实验经验关联式。
In this paper, the heat transfer characteristics of the natural convection of water near its density maximum in a horizontal annulus had been experimentally investigated. The annulus was formed with two copper cylindrical walls, which were concentric or eccentric. The temperature of the outer cylinder was kept at around 0°C and that of the inner cylinder was ranged from 0 to 12°C. In order to enhance heat transfer, three-dimensional external fins were applied on the inner wall. The effects of the gap width and the eccentricity of annulus and the fin geometric parameters on heat transfer were studied. The results show that the two turning points of the average Nusselt number on the inner wall appear at the temperature differences close to 4°C and 8°C, respectively. With the increase of temperature difference, the average Nusselt number firstly increases, and then decreases, finally increases again. The minimum value of the average Nusselt number locates near the temperature difference 8°C. Additionally, it increases with the increase of the gap width of annulus and the eccentricity. Furthermore, when three-dimensional external fins were applied, the average Nusselt number increases with the increase of the fin axial pitch, whereas it decreases with the increase of the fin width. In the range of experimental values, the influences of the fin height and circular pitch are slight. Finally, the experimental empirical correlations of heat transfer on the inner wall are obtained.
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影响因子：
2.2
作者：
S. Nada
通讯作者：
S. Nada
影响因子：
--
作者：
B. Farouk;S. Güçeri
通讯作者：
B. Farouk;S. Güçeri
DOI：
10.1016/0146-6291(77)90475-1
发表时间：
1977-05
期刊：
Deep Sea Research
影响因子：
--
作者：
B. Gebhart;J. Mollendorf
通讯作者：
B. Gebhart;J. Mollendorf
DOI：
--
发表时间：
2004-07
期刊：
Thermal science and engineering
影响因子：
--
作者：
Y. Funawatashi;Shin-ichi Ohta;Tateyuki Suzuki
通讯作者：
Y. Funawatashi;Shin-ichi Ohta;Tateyuki Suzuki
影响因子：
2
作者：
G. Guj;F. Stella
通讯作者：
G. Guj;F. Stella