A simplified model based on multi-phase flow and heat transfer during the quenching process was developed.A set of equations of fluid flow and heat transfer were derived from two-phase fluid dynamics and fluid-solid conjugated heat transfer (CHT）.User-defined functions of the commercial CFD software Fluent were designed for the numerical simulation of fluid flow and heat transfer during the quenching process according to the model.Some influence factors were analyzed and the results showed that the numerical results were consistent with the theoretical analysis.Finally numerical simulation was also done with a rectangular aluminum block

and the computed temperature history within the aluminum block was compared with the temperature history of measured data by using thermocouples in the literature.The error was below 15%.The present model is feasible and captures the major aspects of the quenching process.