# NOVEL APPROACH TO ANALYTICAL MODELLING OF STEADY-STATE HEAT TRANSFER FROM THE EXTERIOR OF TEFC INDUCTION MOTORS

## Main Article Content

## Abstract

The purpose of this paper is to propose a novel approach to analytical modelling of steady-state heat transfer from the exterior of totally enclosed fan- cooled (TEFC) induction motors. The proposed approach is based on the geometry simplification methods, energy balance equation, modified correlations for forced convection, the Stefan-Boltzmann law, air-flow velocity profiles and turbulence factor models. To apply modified correlations for forced convection, the motor exterior is presented with surfaces of elementary 3D shapes as well as the air-flow velocity profiles and turbulence factor models are introduced. The existing correlations for forced convection from a short horizontal cylinder and correlations for heat transfer from straight fins (as well as inter-fin surfaces) in axial air-flows are modified by introducing the Prandtl number to the appropriate power. The correlations for forced convection from straight fins and inter-fin surfaces are derived from the existing ones for combined heat transfer (due to forced convection and radiation) by using the forced-convection correlations for a single flat plate. Employing the proposed analytical approach, satisfactory agreement is obtained with experimental data from other studies.

## Article Details

**Thermal Science**, [S.l.], mar. 2017. ISSN 2334-7163. Available at: <http://thermal-science.tech/journal/index.php/thsci/article/view/2179>. Date accessed: 24 nov. 2017. doi: https://doi.org/10.2298/TSCI150629091K.

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Accepted 2017-03-13

Published 2017-03-13

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