Heat transfer characteristics of pin-fin heat sinks cooled by dual piezoelectric fans

• The heat transfer of heat sinks cooled by dual piezoelectric fans is investigated.
• Compared to a fan, thermal resistance of heat sink with two fans reduces by 16.6%.
• The thermal resistance increases when the elevation of the fans is increased.
• The best performance occurs as the fans place edge to edge and vibrate counter phase.

The heat transfer of pin-fin heat sinks cooled by dual piezoelectric fans is investigated experimentally by infrared thermography. The effects of the phase difference, the configuration, the elevation of the piezoelectric fans, and the dimensions of the heat sinks on the thermal performance of the heat sinks are discussed. The experimental results show that the thermal resistance reaches the minimum (3.37 °C/W) when the fin width is 8 mm, the two piezoelectric fans are in edge-to-edge configuration, and the fans vibrate counter phase in a series of nine-fin heat sinks with a fin height of 15 mm. The minimum thermal resistance (2.4 °C/W) is obtained when the fin width is 5.1 mm and the two piezoelectric fans are in edge-to-edge configuration and vibrate counter phase in a series of sixteen-fin heat sinks with a fin height of 30 mm. The thermal resistance increases significantly when the elevation of the two piezoelectric fans is increased. The effects of the phase difference and the configuration of the two piezoelectric fans on thermal resistance depend on the dimensions of the heat sinks. However, for most tested heat sinks, the minimum thermal resistance is obtained when the two piezoelectric fans are in edge-to-edge configuration and vibrate counter phase.