Heat transfer from extended surfaces subject to variable heat transfer coefficient
Heat transfer from extended surfaces subject to variable heat transfer coefficient
复制标题
来自受可变传热系数影响的扩展表面的传热
DOI：
10.1007/s00231-002-0338-3
复制
发表时间：
2003
影响因子：
2.2
通讯作者：
E. Mokheimer
中科院分区：
文献类型：
--
作者：
E. Mokheimer
本文研究了局部变传热系数对自然对流条件下延伸表面（翅片）性能的影响。不同的配置文件的翅片进行了研究。目前考虑的翅片轮廓是，即，直和针翅片与矩形（恒定直径），凸抛物面，三角形（圆锥形）和凹抛物面轮廓和径向翅片与恒定的轮廓具有不同的半径比。局部传热系数被认为是局部温度的函数，并已获得使用现有的自然对流的相关性为每个相关的扩展表面考虑。翅片的性能用翅片效率表示。比较目前的结果为所有的翅片考虑和相应的翅片得到的结果受到恒定的传热系数沿着翅片。比较，即显示出良好的协议与文献中的实验结果。结果表明，采用定传热系数计算的翅片效率与采用变传热系数计算的翅片效率存在较大的偏差，且偏差随无量纲参数的增加而增大。
The present article investigates the effect of locally variable heat transfer coefficient on the performance of extended surfaces (fins) subject to natural convection. Fins of different profiles have been investigated. The fin profiles presently considered are namely; straight and pin fin with rectangular (constant diameter), convex parabolic, triangular (conical) and concave parabolic profiles and radial fins with constant profile with different radius ratios. The local heat transfer coefficient was considered as function of the local temperature and has been obtained using the available correlations of natural convection for each pertinent extended surface considered. The performance of the fin has been expressed in terms of the fin efficiency. Comparisons between the present results for all fins considered and the results obtained for the corresponding fins subject to constant heat transfer coefficient along the fin are presented. Comparisons, i.e. showed an excellent agreement with the experimental results available in the literature. Results show that there is a considerable deviation between the fin efficiency calculated based on constant heat transfer coefficient and that calculated based on variable heat transfer coefficient and this deviation increases with the dimensionless parameterm.