Development of thermal switch using liquid column

Abstract

Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.This paper presents the thermal switch which is composed of several switching channels, breathing grooves, reservoirs and actuators to control the liquid column. In the “on” state, a switching channel is filled with liquid supplied by an actuator, which decreases the thermal resistance. In the “off” state, the air fills in the gap of two plates instead of the liquid column and the thermal resistance is increased. Through this switch operation, temperature of the designated hot spot can be controlled locally. In order to realize the desired switch operation, the liquid column should be precisely controlled based on channel design. The switching channel is composed of burst area and path area to achieve the smooth operation. The burst area was geometrically designed to provide the hydrophilic surface geometrically by taking into account of burst area. Experiments were performed on a designed switch for the liquid column control and the heat flow regulation. The results showed that this thermal switch is able to make the “on” and “off” state by controlling liquid column well. Also, the temperature distribution and thermal resistance has been changed according to channel state.