Measurement and CFD Prediction of Heat Transfer in Air-Cooled Disc-Type Electrical Machines

Abstract

This is the accepted version of the paper.This version of the publication may differ from the final published version. Abstract-Accurate thermal analysis of axial flux permanent magnet (AFPM) machines is crucial in predicting maximum power output. Stator convective heat transfer is one of the most important and least investigated heat transfer mechanisms and is the focus of this paper. Experimental measurements were undertaken using a thin-film electrical heating method, providing radially resolved steady state heat transfer data from an experimental rotor-stator system designed as a geometric mockup of a through-flow ventilated AFPM machine. The measurements are compared with computational fluid dynamics (CFD) simulations using both 2D axisymmetric and 3D models. These were found to give a conservative estimate of heat transfer, with inaccuracies near the edge and in the transitional flow regime. Predicted stator heat transfer was found to be relatively insensitive to the choice of turbulence model used in the CFD simulations. Permanent repository link

Development of Correlations for Windage Power Losses Modeling in an Axial Flux Permanent Magnet Synchronous Machine with Geometrical Features of the Magnets

“…More importantly, the results were verified with the numerical simulations by Wrobel et al [21] as well as the experimental data by Howey et al [24]. This verification can give us trust in the CFD modeling used in this study.…”

A Computationally Efficient PM Power Loss Mapping for Brushless AC PM Machines With Surface-Mounted PM Rotor Construction

“…Mechanical loss is attributed to the frictional effects within the bearing assembly (bearing loss) and fluid dynamics or aerodynamics effects within the motor body (windage or drag loss) [5]. Electromagnetic losses are usually associated with active parts of the motor assembly and include the iron, winding and permanent magnet (PM) loss components [6]- [8].…”

“…Mechanical loss is attributed to the frictional effects within the bearing assembly (bearing loss) and fluid dynamics or aerodynamics effects within the motor body (windage or drag loss) [5]. Electromagnetic losses are usually associated with active parts of the motor assembly and include the iron, winding and permanent magnet (PM) loss components [6]- [8].Recently, there has been increased interest in methods for accurate and computationally efficient derivation of the electromagnetic loss components [1], [9], [10], that can be easily incorporated within design software tools. Of particular interest is the automated generation of loss/efficiency maps, which have received some attention in the literature [1], [9].…”

Thermal modelling of a low speed air-cooled axial flux permanent magnet generator

“…During operation, the permanent magnets attached onto the rotor disc act in the same way as radial compressor blades pumping a radial flow out from the machine. Topologies of AFPM generators with short axial length and high power density have gained more attention recently in terms of thermal analysis [2][3][4][5]. Convection cooling plays an important role in keeping the generator operating at optimum level.…”