论文部分内容阅读
通过实验研究中心截面沿主流方向带有均匀加热平板的矩形通道混合对流入口段的阻力特性,得到Re数、Gr*数和倾斜角度对阻力系数的影响。实验结果表明:阻力系数随倾斜角度|θ|的增大而增大,在Re数的不同范围内呈不同的特性。Re数小于1500时,阻力系数随Re数的增大而减小,随Gr*数的增大而增大。当Re大于1500时,阻力系数受Re数和Gr*数的影响很小。综合考虑Re数、Gr*数、倾斜角度及管道长径比的影响,对Re数大于1500和小于1 500分别给得出了阻力系数的关联式,该组关联式与实验数据吻合良好,偏差小于10%。
The influence of Re number, Gr * number and tilt angle on the drag coefficient was obtained by experimentally studying the drag characteristics of a rectangular channel mixed convection inlet section with a uniformly heated slab in the center of the section. The experimental results show that the drag coefficient increases with the increase of the inclination angle | θ |, and shows different characteristics in different Reynolds numbers. When the Re number is less than 1500, the drag coefficient decreases with the increase of Re number and increases with the increase of Gr * number. When Re is greater than 1500, the drag coefficient is less affected by Re number and Gr * number. Considering the influence of Re number, Gr * number, tilt angle and pipe length-diameter ratio, the correlation coefficient of resistance coefficient was obtained for Re> 1500 and less than 1 500, respectively. The correlations were in good agreement with the experimental data, Less than 10%.