Thermal Performance Improvement of a Heat Sink With Piezoelectric Vibrating Fins

A heat sink with piezoelectric vibrating fins is developed through attaching piezoelectric actuators to the fins of a heat sink, and the heat transfer characteristics of the heat sink are experimentally investigated. Thermal performance improvement of the heat sink by the vibration of the fins is observed compared to the thermal performance of a natural convection heat sink with static fins under a fixed heat sink geometry condition. The thermal performance of the heat sink changes as the vibration amplitude of the fins or the vibration frequency of the fins changes. Particularly, if the vibration frequency of the fins matches up to the natural frequency of the fins, the vibration amplitude is significantly increased by resonance and the thermal performance also increases. The natural frequency of the fins changes with the heat sink temperature because the geometry of the fins changes and the properties of the fins change due to the temperature change.