【摘要】 对不同倾斜角度的平板在空气中的自然对流换热系数进行了实验测量。采用直接电加热方法对倾斜平板进行加热,在倾斜铜板背面嵌入式布置热电偶测量平板表面平均温度,同时测量电加热时的电压及电流。实验结果表明,随着倾斜表面与空气温差的增加,实验得到的平均努谢尔特数与经典的准则关联式得到的努谢尔特数呈现不同的变化趋势;随着倾斜角度的增加自然对流换热得到了强化,而且当倾斜平板趋于水平或者竖直时实验结果与经典准则关联式的计算结果偏差逐渐增大,最大偏差达到51%。更多还原

【Abstract】 The study on the natural convective heat transfer from an inclined plate in air with different inclined angles and heated surface upward was performed experimentally.The plate was heated with electric heating,its average surface temperature of plate was measured by the thermocouple embedded in back surface of plate current and voltage for the electric heating were measured.The results show that change trends for the Nusselt number from experimental and the values from the classical correlations with the increase of inclined angle and temperature difference are different,and the natural convective heat transfer will be strengthened when the inclined angel increases.The deviations between experiment and calculated Nusselt number will increase gradually when the plate approaches the horizontal or the vertical,and the maximal deviation is about 51%.更多还原