FLOW VISUALIZATION AND ANALYSIS AROUND AN ALTERNATOR

Abstract

To find the mechanism for cooling hot semi-conductors in an alternator mounted on an automobile is important to improve performance of an automobile. The cooling fan on the front end of the alter-nator is installed to suck an air through inlets of the rear cover in order to cool down the hot semi-conductors just inside the rear cover. Thus the cooling air flow is opposite in direction to the movement of an automobile. The flow speed is about I m/s around the alternator. To visualize such a slow air flow the smoke is used, which is produced by burning joss sticks in a specially designed generator. Visualized smoke streaks are analyzed by dig-ital image processing. The obtained streaks show that the flow rate through rear inlets is much smaller than that through the holes on the side wall of the alternator used in our study.