非稳态横掠管束对流传热的数值模拟

In order to study the relationship between heat transfer law and tube spacing,the rationality of using periodic boundary conditions and symmetrical boundary conditions for the full development section of the crossing tube bundle was verified by analyzing the flow field and heat transfer coefficient of different physical models.Numerical simulation of flow and heat transfer in a certain Reynolds number range with different tube spacing across the periodically fully developed section of parallel tube bundles is carried out by using FLUENT software.The results show that the heat transfer effect of densely arranged tube bundles is evidently larger than that of sparsely arranged tube bundles,and for the longitudinal tube spacing S_n/d=1.25 tube bundles,when the transverse tube spacing is about S_p/d=2.0,the heat transfer between tube bundles reaches the strongest,which can provide practical reference for improving the heat transfer capacity of heat exchangers.Finally,the numerical simulation results are compared with previous empirical formulas and experimental results to ensure the accuracy of the numerical simulation method.