Flow in Automotive Alternators

Abstract

A study of the flow field in and around an automotive alternator is described. The approach taken is to test the alternator in water at equivalent in-air Reynolds numbers in order to reduce the rotational velocity by a factor of approximately 15 and provide an environment ideal for flow visualization. The casing and stator were constructed from clear plastic in order to provide visual access inside the alternator. Dye injection flow visualization is used to assess qualitatively the global flow field. Laser Doppler velocimetry is used to perform a detailed, quantitative study of the alternator external flow field. Results from the flow field study are presented and modifications necessary for improved cooling and aerodynamic performance are identified and demonstrated.

Keywords

alternator flow field flow visualization laser Doppler velocimetry

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