Investigation On Heat Dissipation Using Multiple Orifice SJA With Active And Passive Combined Scheme

Synthetic jet is potentially useful for cooling of electronic components as one of the most important application of active fluid control technology.As the microelectronic technology develops rapidly in recent years,the power density per volume gets larger and larger,as a results,effient cooling method for it becomes an essential part of electronic production and quite pivotal during its normal working cycle.Consquensely,promising application prospects are brought to synthetic jet cooling technology.This article made systematic investigation on the heat transfer characteristics of multiple orifice synthetic jet with one single vibrating diaphragm and two chambers(multiple orifice SJA)through the researching method which combined theory deduction,numerical simulation and experiments.Basing on the fundamental theory of heat transfer,the theory Field Synergism of the optimization of convection heat transfer is introduced,the main factors of the heat dissipation performance of synthetic jet as cooling method are deduced as follows: synthetic jet velocity(0U),spanwise distance(r/ D),impinging distance(H/ D),angle between velocity vector and heat flux vector(?),analysis has been made about these factors.3D numerical simulation is made to evaluate the effects of driving frequency and equivalent amplitude on the flow field characteristics of multiple orifice SJA;3D numerical simulation of heat transfer characteristics of multiple orifice SJA is made as well.The effects of impinging distance and the Reynald number on cooling performance is analyzed with the simplized flat plate model of fin heat sink.Results show that it exhibits stronger heat transfer in larger Reynald number than in smaller one,and there is an optimum impinging distance where the heat transfer performance is the best among others.Experimentally investigated the flow field characteristics influencing factors such as driving voltage and driving frequency;To investigate the effects of variable impinging distance,driving voltage and driving frequency on heat dissipation performance,experiments combined fins and multiple orifice SJA have been done.It's found that the effects which impinging distance has on heat dissipation in experiments investigation are the same as that in numerical simulation: there is an optimum impinging distance.And the heat dissipation performs better at the resonance frequency.As the driving voltage increases,the amplitude of vibrating diaphragm gets larger,leading to better performance of the heat dissipation.Under the guiding of the theory Field Synergism and the vectoring characteristics of dual synthetic jet(DSJ),the heat dissipation characteristics in different oblique angle are investigated.The calculation model based on theory Field Synergism is established,and through which,the the integral value,the angle between temperature gradient field and velocity field and the product of the magnitude of velocity and temperature gradient are analyzed with different oblique angle.