Today, more than half the total electrical energy used in industrialized countries is converted to mechanical energy through AC induction motors. The applications for these motors cover almost every stage of manufacturing and processing in factories and industrial centers and domestic environment. simplicity, reliability and low cost make this type of electric motor so popular. The electrical motors similar to the other electrical machines have some losses. Since these losses appear as heat, cooling of the electrical motors is very important. If the heat of inside of the motor doesn’t transfer well to environment, the temperature of the internal components will be increased and thus the windings and insulation life will be decreased. In this study thermal modeling of TEFC electrical motors has been investigated with two methods: thermal equivalent circuit and computational fluid dynamics (CFD). Also effects of applying the axial flow through the air-gap has been studied. For this purpose, the axial flow through the air-gap with different mass flow rate and two directions has been investigated. Results show that applying the axial flow through the air-gap has significant effects on the end-windings conventional heat transfer coefficient and temperature of stator windings and thus motor life. So that, the mean coefficient of heat transfer in stator windings increases by more than 50% with applying a axial mass flow rate of 8 g/s. In this study, it was shown that applying the axial flow in air-gap from drive side to fan side of motor has far more effect than axial flow from fan side to drive side on decrease of windings temperature. So that, in this state and with applying a mass flow rate of 8 g/s, maximum temperature of the windings decreases by more than 6 degrees Celsius. This means that the life of motor could be increased by more than 30%. Keywords: Heat transfer, Electrical energy, TEFC electrical induction motors, Axial flow, Air-gap, Thermal equivalent circuit, Computational fluid dynamics