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本文研究了12种不同形状和椭圆管横放(长轴平行于气流方向)和竖放(长轴垂直于气流方向)在横掠气流中的强迫对流换热。其椭圆管的长、短轴之比分别为1.25,1.50,1.75,2.00,2.25,2.50,2.75,3.00,3.25,3.50,3.75,4.00。作为椭圆管的特例,研究了横掠气流中的圆管(a/b=1)和平板(a/b≈∞)的放热。据据实验结果,对工程上若干种常用的椭圆管以及和平板给出了计算平均放热系数的经验公式。本文还探讨了椭圆管横放和竖放,不同长、短轴之比等因素的影响。作为参考,文中将圆管和平板的实验结果和其它作者的公式进行了比较,比较结果十分满意。
In this paper, forced convection heat transfer in 12 swept air currents of 12 different shapes and elliptical tubes in transverse direction (long axis parallel to the direction of airflow) and vertical (long axis perpendicular to the direction of airflow) were studied. The oval tube of the long and short axis ratio were 1.25,1.50,1.75,2.00,2.25,2.50,2.75,3.00,3.25,3.50,3.75,4.00. As a special case of elliptical tube, the exothermicity of the circular tube (a / b = 1) and the flat plate (a / b ≈∞) in a swept air flow was studied. According to the experimental results, some empirical formulas for calculating the average exothermic coefficient are given for several kinds of commonly used oval pipes and plates in engineering. This article also discusses the elliptical tube horizontal and vertical, different length, short axis ratio and other factors. As a reference, the experimental results of the pipe and the plate are compared with those of other authors, and the results of the comparison are very satisfactory.