不同边界条件下管翅式换热器流动与传热性能的POD分析

POD analysis of flow and heat transfer performance of tube fin heat exchanger on different boundary conditions

传统的数值模拟计算时间长,很难满足现代工业发展需求。采用适体坐标与本征正交分解(POD)相结合的方法在等壁温和等热流两种边界条件下对扁管管翅式换热器进行降维计算,并将计算结果与有限容积法(FVM)计算结果进行了对比。结果表明:POD方法在等壁温和等热流边界条件下均能获得物理过程的准确信息,并将传统FVM数值计算速度提高了3093倍。采用POD方法重构温度场时,在等壁温和等热流条件下相对偏差平均值的最大值分别为0.557%和0.308%。重构速度场时,在等壁温和等热流条件下相对偏差平均值的最大值分别为1.26%和1.9%,这一结论可为换热器的数值设计中合理设置边界条件提供理论依据。

The traditional numerical simulation calculation time is long,and it is difficult to meet the needs of modern industry development.The method of combining body-fitted coordinates and proper orthogonal decomposition(POD)reduced-order model is used to calculate the heat transfer units of the flat tube fin heat exchanger.And its calculation results are compared with the results of the finite volume method(FVM).The results show that the POD method can accurately obtain the actual information under the boundary conditions of uniform wall temperature and uniform heat flux.But also,the calculation speed of POD is 3093 times of FVM.As for the cases of reconstructing the temperature field,the maximum error values under the boundary conditions of uniform wall temperature and uniform heat flux are 0.557%and 0.308%,respectively.As for the cases of reconstructing the velocity field,the maximum error values under the boundary conditions of uniform wall temperature and uniform heat flux are 1.26%and 1.9%,respectively.The conclusions of this study can supply theoretical reference for reasonable boundary condition in numerical design of the heat exchanger.