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导出了无量纲的支配方程组，能适用于壁面为定热流或定壁温的边界条件．采用原始变量方法，利用ＳＩＭＰＬＥＣ算法进行了求解．在较为宽广的瑞利数Ｒａ和半径比范围内分别对定热流和定壁温两种情况进行了计算并得到了相应的结果．流场中存在着半月形的涡旋，而径向的温度分布在一定角度范围内有温度反转现象．平均换热Ｎｕ随Ｒａ和半径比的增加而上升，定热流的换热要略强于定壁温情况下的值．整理了水平同心套管换热的关联式，并对两种边界条件进行了比较．所得结果与有关文献进行了比较，相符较好
The dimensionless governing equations are derived and can be applied to boundary conditions where the wall is constant heat flow or constant wall temperature. Using the original variable method, using SIMPLEC algorithm for solving. Two cases of constant heat flow and constant wall temperature were calculated and the corresponding results were obtained respectively in the range of Ra and radius ratio. There exists a semilunar vortex in the flow field, while the radial temperature distribution has a temperature reversal phenomenon within a certain angle range. The average heat transfer Nu increases with the increase of Ra and radius ratio. The heat transfer of constant heat flow is slightly higher than the value of constant wall temperature. The correlation of horizontal concentric bushing heat exchangers was sorted out and the two boundary conditions were compared. The results obtained are compared with the relevant literature, which is in good agreement