A three-dimensional numerical study on heat transfer characteristics of flow in a channel with fins attached to one wall

Three dimensional numerical computation was performed for the developing region of flow and thermal fields in an internally finned channel The channel studied here has a heated area of finite length to which plate fin arrays are attached in order to improve its heat transfer performance. The performance was evaluated suing Nu(L)*. Nusselt number corresponding to the heat transfer rate per unit heated area. The effect of fin height, fin pitch, fin length and Reynolds number on Nusselt number was examined parametrically Changing the fin height with the fin pitch kept constant, the maximum value of Nu(L)* was obtained when fin top reached the top wall of the channel On the other hand, when the fin pitch was changed with the fin height kept constant, the numerical results demonstrated two kinds of tendencies. In the case with clearance between the fin top and the top wall there existed the optimum fin pitch which makes Nu(L)* maximize. In the case without the clearance. Nu(L)* increases with decrease of fin pitch The optimum value of fin pitch gradually decreased with decreased with decrease of fin length and or with increase of Reynolds number. The ratio of j-factor to f-factor was also obtained to evaluate the performance of the fins.