非平直下壁面对辐射吸收引发的对流影响研究

Study on the Influence of Non-Uniform Lower Wall on Convection Induced by Radiation Absorption

摘要: 对非平直下壁面辐射驱动的自然对流进行了数值模拟，基于ANSYS FLUENT求解控制方程，分析了几何参数和Rayleigh数对辐射驱动自然对流流动和传热的影响。结果表明，随着Rayleigh数的增加，流函数的对称结构被破坏，上方流线图变得近似水平，小波长的工况会出现水平流动；几何参数对羽流穿透深度和下壁面温度分布有重要影响，随着振幅的增大，系统的温度均匀性变小，当周期个数为1时，羽流穿透深度最大；当波长长度为1.8时，下壁面温度分布出现过渡情况，由波峰温度最高变为波谷温度最高。

Abstract: A numerical simulation of radiation-driven convection on a non-flat lower wall is carried out. The influence of geometric parameters and Rayleigh number on radiation-driven natural convection flow and heat transfer is analyzed by solving the governing equation based on ANSYS FLUENT. The results show that with the increase of Rayleigh number, the symmetric structure of the stream function is destroyed, the upper flow plot becomes nearly horizontal, and horizontal flow occurs in the condition of small wavelength. The geometrical parameters have an important effect on the plume penetration depth and the temperature distribution on the lower wall. With the increase of the amplitude, the temperature uniformity of the system becomes smaller. When the number of periods is 1, the plume penetration depth reaches the maximum. When the wavelength length is 1.8, the temperature distribution of the lower wall appears a transition, from the highest peak temperature to the highest trough temperature.