The steady-state three-dimensional numerical models for predicting the thermal hydraulic performance for transverse direction (TD) and longitudinal direction (LD) flow through the serrated fins were developed. Firstly, taking oil as working fluid, three samples of LD type serrated fin cores were simulated in order to validate the feasibility and reliability of the numerical models. Next to that, the flow and heat transfer characteristics in TD type serrated fins were analyzed numerically and the global properties (j and f factors) obtained in the simulations were compared with the available experimental data. Based on these simulations, a detail description of local and average heat transfer characteristics of the two types of serrated fins was presented and discussed. The experimental results show good agreement with the corresponding numerical predictions. Hence, the numerical analysis procedure proposed in this paper can be used to predict the performance of new type fins. (C) 2010 Elsevier Ltd. All rights reserved.