Structure Optimization And Heat Transfer Characteristics Of Multiple Holes Array Microjet Heat Sink

In recent years,our chip industry has developed rapidly,combined with the whole chip development history,chip has been developing towards a highly integrated direction,chip heat dissipation will become the key technology in its development process.Therefore,exploring different heat transfer technologies for chip cooling has become a research hotspot in this field.Among them,jet cooling technology stands out among many cooling technologies because of its simple structure and high heat transfer effect.In this paper,structural optimization is carried out by changing the inlet structure and return structure of an array porous micro-jet heat sink and adding fin structure to it.The heat transfer characteristics of six kinds of structures are studied by combining simulation and experiment.In the numerical simulation stage,ANSYS ICEM software was used to build six geometric models,including array porous micro-jet heat sink(circular backflow structure),annular backflow structure,side intake structure,two-layer intake structure,cylindrical fin structure and prismatic fin structure.The mathematical model was established and simplified according to the actual working conditions,and reasonable solving conditions were set up.FLUENT software was used for simulation.In the experimental research stage,air is used as the cooling medium,and the test system is designed reasonably according to the experimental requirements,and the experimental platform is built.Array microfluidic heat sink of different structures is manufactured by 3D printing technology,and thermal conductivity plate,cylindrical fin plate and prismatic fin plate are processed in Computer numerical control technology.Various parameters that can characterize the heat transfer effect of different structures are tested by experiments.Through formula calculation,error analysis and theoretical analysis,the heat transfer characteristics of micro-jet heat sink under different structures are obtained,which provides experimental data and basis for evaluating the performance of heat sink with different structures.The flow field,temperature field,the average temperature of the cooled surface,the average convective heat transfer coefficient,the average Nusselt number,the pressure difference between the inlet and outlet of the fluid,the thermal resistance of the cooled surface and the energy efficiency ratio of the six heat sink structures were analyzed.The results show that:When the heat flux on the heated surface of heat sink is 14 230 W/m~2,21 345 W/m~2and 28 460 W/m~2,and the jet Reynolds number is between 1 664.64 and 2496.96,the average temperature of heat sink is 34.62℃and 71.67℃respectively.The average heat transfer coefficient ranges from 507.65-973.32 W/(m~2·K),the average Nusselt number ranges from 19.60-37.58,the pressure difference between inlet and outlet of the fluid ranges from 1 395.38-6 280.00 Pa,and the thermal resistance of the cooled surface ranges from 1.41-2.70 m~2·K/W.The energy efficiency ratio ranges from 1.05 to17.56.The jet Reynolds number will have a positive impact on the average temperature of the cooled surface,the average convective heat transfer coefficient and the average Nusselt number,and the impact will gradually weaken,while the heat flow density has little impact.Compared to the average temperature and thermal resistance of the cooled surface of the circular reflux structure,the side inlet structure decreased by 1.91%and3.03%,the two-layer inlet structure decreased by 3.42%and 5.53%,respectively,but the pressure loss increased by 61.65%,the annular reflux structure decreased by 5.41%and8.82%,the cylindrical rib structure decreased by 8.43%and 13.77%,and the prism rib structure decreased by 11.80%and 19.17%,respectively.After comprehensive analysis,the heat dissipation performance of six structures is ranked as follows:prism-fin structure,cylindrical fin structure,annular reflux structure,side intake structure,circular reflux structure,and two-layer intake structure.This study provides a reference direction for structural optimization of heat deposition of array porous micro-jet.