Experimental and Numerical Investigations of Synthetic Jet Used for Electronic Cooling

Abstract

Cooling of electronics and micro-electronics devices is an important task in our present world. Synthetic jet is a relatively new technique for electronic chip cooling which synthesizes stagnant air to form a jet resulted from periodic oscillations of a diaphragm in a cavity. Synthetic jet cooling increases the rate of heat transfer as compared to other cooling techniques. The impingement heat transfer characteristics of a synthetic jet is studying in this work. Synthetic jet is driven by a piston-cylinder arrangement a through circular nozzle for the impingement of jet on the heated surface. Air is considered as the cooling medium. Heat flux is taken as 8000W/m2. Numerical simulations and experimental methods are conducted to study the effect of various distance between the orifice and the heated plated(Z). A circular orifice is used to study the characteristics of convective heat transfer. The results are verified by the time history of convective heat transfer characteristic and validated with experimental results. The model was simulated to investigate the dispersion of heat flow on the walls using a mathematical turbulent model of k- ω SST. The Reynolds number (Re) is in the range of 4000-8000 based on average velocity, while the normalized impinging distance varies between 2D to 10 D The results shows the significant influence of Z/D ratio and sinusoidal wave frequencies to the heat transfer rate obtained. Experimental and numerical investigations is carried out to study the variation of Nusselt number with jet velocity. It is found that the Z/D ratio at 6 gives the maximum amount of cooling for a flat plate.

Current Review on Numerical Simulation of Synthetic Jet (SJ) Cooling

“…Type of flow Turbulence model Chen et al, [10] ANSYS Fluent PISO -k-omega SST D' Alencon et al, [11] ANSYS Fluent SIMPLE Transient conventional k-SST Benayad et al, [14] ANSYS Fluent -Transient, incompressible k-omega SST Huang et al, [16] ANSYS Fluent SIMPLE Incompressible k-omega SST Mohammadshahi et al, [19] -SIMPLE Incompressible k-omega SST Li et al, [22] --Transient, incompressible, k-turbulence SST Yeom et al, [52] ANSYS Fluent SIMPLE Incompressible k-omega SST Rulik and Wroblewski [24] ANSYS Fluent Transient, compressible k-omega SST Lau et al, [25] -SIMPLE Incompressible -Kumar et al, [27] ANSYS Fluent SIMPLE Transient, incompressible -Qiu et al, [34] -SIMPLEC Transient, incompressible -Tan et al, [37] ANSYS Fluent SIMPLE Incompressible k-turbulence SST Geng et al, [42] ANSYS Fluent PISO Transient, incompressible k-omega SST Fisher et al, [43] ANSYS Fluent PISO, SIMPLE Transient, steady k-turbulence SST Hoh et al, [44] ANSYS Fluent PISO Transient, incompressible -…”

“…Jacob et al, [43] uses numerical analysis to determine the HTC of a SJ emerging from a circular orifice at H/d=6. The outcome demonstrates the importance of the H/d and sinusoidal wave frequencies on the measured heat transfer rate.…”