Numerical simulation and experimental verification of heat transfer from a finned housing of an electric motor

Highlights: • Heat transfer in a finned housing of an electric motor was investigated. • Numerical simulation and thermographic measurements were employed. • The flux of heat losses from the housing to the environment was verified. • Temperature distribution on the surface of a housing fin was determined. • The methodology of simulation combined with thermography proved effective. - Abstract: Engineering analyses based on the results of numerical simulation enable shortening the duration and reducing the costs of the development and tests of equipment models or prototypes. As numerical modeling methods have uncertainties, experimental verification is required. In the literature, there are many examples of application of numerical modelling to the thermal processes occurring in electric motors but the experimental methods of model validation are not so well described. In this work, numerical and experimental investigations of heat conduction in the finned housing of an electric motor, and the comparison between their results are presented. 3D geometrical model of the motor rated 7.5 kW was imported to COMSOL Multiphysics software package. After defining thermophysical properties of the housing material and heat flows generated in the motor, and setting boundary conditions, a numerical model of heat conduction in the motor housing was obtained. The model allowed to calculate steady-state temperature distribution in the housing cross section. In order to validate the model, investigations of the temperature distribution were carried out using FLIR SC7600 thermovision camera. Steady-state temperature distribution on the surface of housing of the motor run in idling conditions was recorded by thermography. The obtained thermograms were found to be in satisfactory quantitative agreement with the simulated temperature distribution as the real values of temperature differences measured across the housing cross section deviated not more than 10% from the calculated ones. The research confirmed that a thermovision camera is an efficient experimental tool for the validation of numerical models of the heat transfer phenomena in the finned housing of an electric motor.