Convection Heat Transfer and Flow Calculations Suitable for Analytical Modelling of Electric Machines

Motor-CAD is a commercial software package dedicated to the optimisation of motor cooling. Its solver is based on thermal lumped circuit analysis. This provides near instantaneous calculations speeds allowing 'what-if' scenarios to be run in real time. The user inputs geometric data for the design they wish to simulate using the graphical radial and cross-section editors. Materials to be used in the machine and the cooling type to be modelled (TENV, TEFC, liquid cooling, etc) are selected. All thermal parameters such as conduction, radiation and convection thermal resistances are then calculated by the program and the thermal performance calculated. This article concentrates on the formulations used to predict the convection cooling and flow within the machine