Heat Transfer Characteristics Of Piezoelectric Synthetic Jet Heat Sinks

Nowadays,the energy consumption and heat dissipation are seriously obstructing the development of the high performance chips towards miniaturization and integration,the efficient cooling system and thermal control technology is a matter of urgent priority.Synthetic jet technology is a new type of jet technology,which has low power consumption and high heat dissipation efficiency,the synthetic jet actuator structure can work without rotating components and fluid feeding.It has become a research hotspot,which will show good application potential and broad application prospects for enhanced heat transfer and cooling of electronic devices.With the significant flow characteristics,the combination of synthetic jet and heat sinks is an effective cooling technology,but it has no systematic results.In this paper,theoretical,experimental and numerical simulation methods are used for the research of heat transfer characteristics of synthetic jet heat sinks.The main work embodied as follows:(1)Based on the theory of piezoelectric vibrator and the synthetic jet,a method of analysis and design for the mechanical,electrical and thermal coupling system of piezoelectric synthetic jet actuator is established.And the ANSYS is utilized for analyzing piezoelectric vibrator model of the selected material to get the vibration displacement function of piezoelectric vibrator in sinusoidal electric signal.The dynamic grid technology of FLUENT is used to verify the grid independence of the dynamic boundary model of the synthetic jet and the theoretical formula of the velocity of the outlet center flow line.The structural parameters of the actuator which affect the velocity field of the synthetic jet are analyzed,and the piezoelectric synthetic jet actuator is fabricated under the optimized structure size.(2)Based on the comparative analysis of three synthetic jet simulation methods,a modified export velocity model for accelerating the calculation speed is put forward,and a synthetic jet heat dissipation simulation model is constructed,the heat transfer characteristics of synthetic jet direct heat dissipation and synthetic jet heat sink heat dissipation are systematically studied.The effect of different outlet holes and holes spacing of actuator on the direct heat dissipation of synthetic jet is simulated and analyzed,and the cooling effect of synthetic jet under different conditions is verified through the experimental test system.Five types of heat sinks,such as cylindrical L and ladder type,are designed.The heat transfer characteristics under different outlet conditions are compared and analyzed,and the scheme of optimizing the synthetic jet heat sink is determined.(3)The optimum design of the orthogonal test of the structural parameters of the synthetic jet heat sink is carried out in two optimization objectives including the thermal resistance and the weight of the heat sink,combined with a weighted scoring method evaluating the comprehensive performance,and the structure of the cylindrical O and rectangular slit synthetic jet heat sinks with superior performance is obtained.Based on that,the heat dissipation performance of two optimized structures is verified through the comparative analysis between experiment and simulation.