ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Effect of Electrode Configuration on the Heat Transfer Performance of a Concentrated Heat Source
Аннотация
In this study, enhancements of LED cooling using ionic wind subject to various electrode configurations are
presented. A total of six needle type electrodes, including sharp, 0.08 R, 0.12 R, 0.37 R, 0.49 R and flat tip, are
used in the experimentation. The effects of electrode configuration, vertical separation height, and tilt angle on
the cooling performance of a LED are reported in this study. With the rise of supplied voltage, the thermal
resistance is reduced and a maximum 50% reduction is achieved before the spark-over voltage. For the same
supplied voltage, the thermal resistance with a larger vertical separation is also higher. However, the operational
range is also longer. The effect of tilt angle on the cooling performance of LED depends on the supplied voltage.
For a supplied voltage less than 6.5 kV with a tip radius of 0.12 R, it is found that the thermal resistance is
reduced when the tilt angle is reduced. However, the trend is reversed when the supplied voltage is higher than
6.5 kV where the thermal resistance of a smaller tilt angle is lower than that of a larger tilt angle. For the same
mesh ground, the effect of electrode configurations cast little influence on the final thermal resistance. All types
of electrode can provide an approximately 50% reduction of its original thermal resistance. However, the
corresponding threshold voltage and operational voltage differs significantly. The threshold voltage is lowest for
the sharp needle and is increased with the rise of tip radius. On the other hand, the corresponding operational
range becomes narrower when the tip radius is increased. Nevertheless the spark-over voltage is also insensitive
to change of electrode configuration.
Ключевые слова:
Thermal management, Electronic equipment cooling, Electrohydrodynamics, ionic wind, threshold voltage