Study of piezoelectric fan between heat dissipation fins in a LED lighting system
Date Issued
2011
Date
2011
Author(s)
Ho, Wei-Han
Abstract
Previous studies show that the lighting quality of LED largely depends on operating temperature. LED devices without thermal management may fail early due to thermal runaway, epoxy degradation, and thermal stress under high-operating temperatures. Piezoelectric fans have emerged as a viable cooling technology for the thermal management of low power electronic devices, owing to their low power consumption, minimal noise emission, and small and configurable dimensions. Previous study also shows the temperature of the heat source may reduce from 70.6℃to 37.4℃ by a piezoelectric fan in the case of heat plate.
The performances of the piezoelectric fans depend on amplitude of piezoelectric fan, vibration frequency, the direction of gravity, and relative position between heat source and piezoelectric fan. The heat transfer performance for horizontal location arrangement shows best performance at Xpzt/Lfin = 0.6. Based on the dimensionless analysis to the experimental results, the relationship with Repzt and Nupzt is linear when Repzt < 700. It’s is observed that the parameter γ=Gr/Repzt represents the importance of natural convection relative to forced convection. When γ < 1, natural convection is negligible. When γ > 10, forced convection is negligible.
The performances of the piezoelectric fans depend on amplitude of piezoelectric fan, vibration frequency, the direction of gravity, and relative position between heat source and piezoelectric fan. The heat transfer performance for horizontal location arrangement shows best performance at Xpzt/Lfin = 0.6. Based on the dimensionless analysis to the experimental results, the relationship with Repzt and Nupzt is linear when Repzt < 700. It’s is observed that the parameter γ=Gr/Repzt represents the importance of natural convection relative to forced convection. When γ < 1, natural convection is negligible. When γ > 10, forced convection is negligible.
Subjects
Piezoelectric fan
heat dissipation
natural convection
force convection
Type
thesis
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