Study On The Heat Transfer Performance Of A Jet Impingement Microchannel Heat Sink Coupled With Ribs

With the continuous upgrading of central processing units(CPUs)and graphics processing units(GPUs)and the advancement of technology,the performance of electronic devices has been significantly improved.However,these improvements come with an increase in power consumption,resulting in a continuous rise in the internal temperature of the devices.Therefore,the heat dissipation problem of electronic devices has become the focus of widespread concern.Jet impingement has been shown to improve the heat transfer coefficient of microchannels,and ribs can enhance the overall heat transfer performance.This paper proposes microchannel heat sink under the effect given by ribs and jet,which exhibits both excellent thermal performance of ribs and high heat transfer of jet impingement.This paper studies the thermal performance of the jet impingement microchannel heat sink coupled with ribs,with water serving as the cooling medium.This article first compares the microchannel heat sink with ribs with the smooth microchannel heat sink.The research results show that under the same inlet Reynolds number of 3000,the temperature of the microchannel heat sink with ribs can reduce by8.78%at most.Then,the geometric parameters of the microchannel flow channel with ribs and the arrangement of ribs are studied.The results show that when the width ratioα=0.65 and the height ratioβ=0.54,the microchannel heat sink has a higher performance evaluation criteria(PEC)and a lower baseplate temperature.When the number of rib rows is 3,it can achieve better heat dissipation and higher PEC,and the PEC of staggered arrangement of rib is 2.3%higher than that of the straight arrangement.As the longitudinal distance L1 of the ribs increases,the temperature of the microchannel heat sink decreases,and the PEC growth rate gradually decreases.As the transverse distance L2 of the ribs increases,the PEC of the microchannel heat sink first increases and then decreases,reaching the maximum value at L2=0.24,and the baseplate temperature reaches the minimum value at L2=0.3.Then,the rib radius is studied.Under the same inlet Reynolds number,as the radius increases,Nu and PEC gradually increase,the baseplate temperature decreases,and the temperature uniformity becomes better.Under the same pump power,PEC shows a trend of first increasing and then decreasing with the increase of rib radius R.In order to further enhance the heat dissipation performance of jet impingement microchannel heat sink coupled with ribs,a study on the morphology of ribs is conducted.The effects of rib segmentation,truncation,and different cross-sectional shapes on the improvement of heat performance are studied.Additionally,the heat transfer characteristics of different jet inlet parameters in the microchannel are analyzed.The results show that the PEC first increases and then decreases as the rib segmentation distance d increases,reaching the maximum at d=1.5R.The truncation height H2 of the rib also has a certain impact on the heat exchanger.As H2 increases,the PEC first increases and then decreases,with PEC reaching its maximum at H2=0.1mm.With the increase of the truncated position,the PEC first becomes larger and then decreases,and the performance is relatively good when the truncation is in the middle position.The study of four different rib shapes(cylindrical,elliptical,hydrofoil and triangle)show that the hydrofoil rib has the highest PEC.The parameters of the hydrofoil rib are optimized,and the simulation results show that the best improvement effect is achieved when the parameter is a2b1.To improve fluid heat transfer,the inlet parameters of the jet are optimized,and it is found that the best heat transfer efficiency of the jet impingement microchannel heat sink coupled with ribs can be achieved when the inlet aspect ratioγis 1.4:0.4.Finally,the performance of four kinds of optimized jet microchannel coupled fin radiators is compared and analyzed under the heat flux in the range of 50～450W/cm~2,including cylindrical rib separated microchannel heat sink(CRS-MCHS),cylindrical rib truncation microchannel heat sink(CRT-MCHS),hydrofoil rib microchannel heat sink(HR-MCHS),and hybrid microchannel heat sink(H-MCHS).The results show that with the increase of q,Nu increases,f decreases,and PEC increases accordingly.The existence of hydrofoil rib can keep the friction factor of HR-MCHS and H-MCHS at a low level,while the rib segmentation can make Nu of CRS-MCHS and H-MCHS maintain a relatively high level.The H-MCHS,consisting of rib segmentation,rib truncation,and hydrofoil rib,has the highest PEC among the four,with a larger Nu and a smaller f.This study provides theoretical basis and practical guidance for the design and optimization of heat sinks of electronic components,and provides support for improving the reliability and stability of electronic components.