Mei Su

The Characteristic Temperature in the Definition of Heat Transfer Coefficient on the Fin Side Surface in Tube Bank Fin Heat Exchanger

The characteristic temperature in the definition of the fin side surface heat transfer coefficient of two tube bank fin heat exchangers is investigated in detail. The results reveal that if the average temperature of the fin side fluid is used in the definition of the fin side surface coefficient, a small discrepancy between the numerical and experimental results is obtained. The results not only give a technical definition of the characteristic temperature of the fin side surface heat transfer coefficient, but also imply that the discrepancy between experimental and numerical results may come from incorrect use of the characteristic temperature.

The criteria of convergence in conjugated simulation of fluid flow and heat transfer in the channel formed by tube bank fins

The criteria of convergence of many reported numerical studies of conjugate heat transfer in tube bank fin heat exchangers have not been clearly addressed. In this paper, the criteria are addressed clearly. The results show that when the relative error of any field variable or characteristic number is less than certain value is chosen as convergence criterion, the balance between the heat transferred from and to the fins cannot achieve. This implies that in numerical method using conjugated method, the physical requirement of the studied problem must be enforced in choosing the criteria of convergence.