Thermal performance of a dual-sided multiple fans system with a piezoelectric actuator on LEDs

With the advantages of lower power consumption and longer lifetime, piezoelectric fans have been widely investigated for use in electronic cooling for many years. However, the application of the piezoelectric fans for LEDs is seldom explored because of its insufficient cooling ability. In this study, a dual-sided multiple fans system with a piezoelectric actuator (“D-MFPA”) is considered for use in the thermal management of LEDs. The obvious advantage is that the D-MFPA only uses one piezoelectric fan to drive eight passive magnetic fans vibrating simultaneously to provide sufficient cooling ability and two-directional air flows. Two 30-W chip-on-board (COB) LED models are adopted to investigate the thermal performance of the D-MFPA. The dimensionless heat convection number for the D-MFPA (MD ‐ MFPA) is defined in this study to describe and quantify the thermal performance of the D-MFPA. Moreover, several horizontal orientations (x/Sl) and vertical orientations (y/Sh) are examined to investigate the effects of different arrangements. The results indicate that MD ‐ MFPA can be improved to 3.92 under the case of x/Sl = 0 and y/Sh = 0.033; however, the single piezoelectric fan can only improve MD ‐ MFPA to 2.82.