A THEORETICAL AND EXPERIMENTAL INVESTIGATION OF THE SCALING OF MICRO FAN PERFORMANCE

摘要

Mobile phones and palm top computers are following trends of increased functionality and processor speed. To allow these trends to continue, compact cooling solutions are required. One potential solution is to introduce cooling fans. However, no fan currently exists which is small enough. This paper investigates the feasibility of producing a fan on the micro scale, which could be used. Theoretical analysis predicts a reduction in efficiency as fan size is reduced. A series of geometrically similar fans was produced so that the scaling could be experimentally investigated. These fans varied in size from the macro to the micro scale. The macro scale fan, which was used as a datum, is typical of those used to cool macro scale electronic systems. The authors developed techniques for the fabrication of the smaller scale fans. These included micro electro discharge machining. Methods for testing the performance of each of these fans were also developed. The pressure flow performance of each of the fans is measured, and confirms that as the micro scale is approached fan efficiency decreases. The observed decrease in efficiency is in agreement with theoretical prediction.