含加热圆管方腔内自然对流的数值研究

采用数值计算方法对含不同直径圆管以及相同直径圆管位置不同方腔内的层流自然对流进行了研究。以冷热壁面温度差为基准的瑞利数Rn为10^6，以圆管壁面热流密度为基准的Ra为10^8。计算结果表明，当圆管处于方腔中间位置时，随着圆管直径的增大，圆管表面局部努塞尔数呈减小趋势。当圆管直径不变时，由于在不同位置处浮力作用的强弱不同，随着圆管在方腔内位置的改变，方腔内流场结构和温度场分布也会发生变化。整个计算结果可为工程设计提供参考。

Numerical investigation of natural convection in square cavity containing heated circular pipe

Numerical method was employed to investigate the laminar natural convection for two cases in a square cavity containing a circular pipe. varied pipe diameter at the center of the cavity and the same pipe at different position in the cavity. Rayleigh number based on the temperature difference between the cold and hot wall was while the Rayleigh number based on the heat flux through the pipe was. The result indicates as the diameter of the pipe fixed at the center of the cavity increases, the local Nusselt number along the pipe surface decreases. When the pipe with the same diameter changes its position in the cavity, the flow field and temperature distribution are affected because of the different intensity of buoyancy at different positions. The results can provide a reference for engineering design.