This thesis describes the design and the numerical evaluation of the combined liquid-air cooling system in an electric motor. The introduction presents contracting authority’s demands and the theoretical basis of the addressed problem. This provides the basis for analyses of existing electric motor air cooling solutions and analyses of the proposed concept of the combined liquid-air cooling system. Next, we describe the temperature measuring process in the existing electric motor and the process of making a measuring instrument to measure the temperature in the rotor. This part also presents the airgap problem between the rotor and stator, which consists of difficulties describing local conditions such as: fluid velocity, heat flows etc. For this purpose the validation of the numerical simulation is given, which is based on existing articles and literature. Then two electric motors are analysed, namely the existing electric motor which is validated with the help of the preliminarily measured temperatures, and the electric motor with the combined liquid-air cooling system. We then compare the analysis of the existing electric motor and the analysis of the electric motor with the liquid-air cooling system, noticing an increased mass flow of the air flow through the channels of the rotor package and air circulation inside the electric motor.
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