努塞尔数
自然对流
无量纲量
瑞利数
机械
传热
材料科学
流动可视化
瑞利散射
对流
热力学
涡流
流量(数学)
几何学
雷诺数
光学
物理
湍流
数学
作者
Luis Fernando Alzuguir Azevedo,E. M. Sparrow
摘要
Heat transfer and flow visualization experiments were carried out in water to investigate the effect of inclination on natural convection in a parallel-walled channel. Parametric variations were also made of the dimensionless interwall spacing S/H, the mode of heating, and the wall-to-ambient temperature difference (i.e., the Rayleigh number Ras). The heating modes included: (I) both walls heated and maintained at the same uniform temperature, (II) heating only from above, and (III) heating only from below. The Nusselt number results for top-heated channels inclined at an angle θ and for the vertical one-sided heated channel were perfectly correlated by the single parameter (S/H)Rascosθ. On the other hand, the results for bottom-heated channels displayed a separate dependence on S/H, Ras, and θ. The Nusselt numbers for two-sided heating exceeded those for one-sided heating for vertical and moderately inclined channels, with a mixed trend at high inclinations. The global correlation Nus = 0.645[(S/H)Ras]1/4 represented all the results within ±10 percent. Recirculation zones were present adjacent to the unheated wall of top-heated and one-sided heated channels. In the presence of heating from below, secondary flows in the form of longitudinal vortices existed above a threshold Rayleigh number.
科研通智能强力驱动
Strongly Powered by AbleSci AI