管翅式换热器流动和换热的低阶模型模拟

采用最佳正交分解技术(POD)建立管翅式换热器的低阶模型,通过数值模拟的方法得到管翅式换热器在雷诺数为100~2 000时的流场和温度场。通过对系统样本实施最佳正交分解得到该物理问题的POD基函数和谱系数。POD基函数具有能量最优的特性,即在重构公式中使用较小的截断自由度可将原物理问题的解准确地表示出来,重构公式在非设计参数时的谱系数由线性插值的方法得到。研究结果表明,基于POD的低阶模型可以快速、准确地预测出管翅式换热器内的温度场和速度场,计算时间仅为SIMPLE算法的1/1 200。

Reduced order modeling of fluid flow and heat transfer in tube-fin heat exchanger

The reduced order model(ROM) of a tube-fin heat exchanger was developed based on the proper orthogonal decomposition(POD) technique.The flow and temperature fields of a tube-fin heat exchanger were obtained from numerical simulation at different Reynolds number,which is 100-2000.The best orthogonal decomposition method was used to the system sample to get POD basis functions and spectral coefficient.The POD basis function has the best characteristics of energy.In the reconstruction formula,a smaller cut freedom may be the solution of the original physical problem accurately.The spectral coefficient in non-design parameters was obtained by linear interpolation at the reconstruction formula.The results show that the reduced order model can predict the temperature and velocity field of the tube-fin heat exchanger quickly and accurately and the calculation time is 1200 times faster than that of SIMPLE algorithm.