TITLE:
CFD Study of Forced Air Cooling and Windage Losses in a High Speed Electric Motor
AUTHORS:
Kevin R. Anderson, Jun Lin, Chris McNamara, Valerio Magri
KEYWORDS:
Electronics Cooling, High-Speed Motor, Windage Losses, Conjugate Heat Transfer
JOURNAL NAME:
Journal of Electronics Cooling and Thermal Control,
Vol.5 No.2,
June
25,
2015
ABSTRACT: High speed and high efficiency synchronized electric motors are favored in the automotive industry and turbo machinery industry worldwide because of the demands placed on efficiency. Herein an electric motor thermal control system using cooling air which enters from the drive end of the motor and exits from the non-drive end of the motor as the rotor experiences dissipates heat is addressed using CFD. Analyses using CFD can help to find the appropriate mass flow rate and windage losses while satisfying temperature requirements on the motor. Here, the air flow through a small annular gap is fed at 620 L/min (0.011 kg/sec) as the rotor spins at 100,000 rpm (10,472 rad/sec) and the rotor dissipates 200 W. The CFD results are compared with experimental results. Based upon the CFD findings, a novel heat transfer correlation suitable for large axial Reynolds number, large Taylor number, small annular gap Taylor-Couette flows subject to axial cross-flow is proposed herein.