Numerical Simulation Of Flow And Heat Transfer Characteristics In Y-shaped Ribbed Microchannels

With the rapid development of industrial technology,in aerospace,energy and power,microelectronics technology,laser technology and other engineering fields,advanced equipment and devices are developing in the direction of small size,light weight,and high heat flux.More advanced heat is required.Due to the control technology,the traditional micro-channel radiator is increasingly unable to meet the heat dissipation requirements.Therefore,the development of a micro-channel radiator with better heat transfer performance has very important practical significance.In this paper,the Y-shaped rib microchannel is designed,and its enhanced heat transfer mechanism is revealed based on the secondary flow theory.The flow parameters（Re）and the structure parameters of the spoiler element are used to study the flow and heat transfer characteristics of the Y-shaped rib microchannel based on the control variable method.The influence of Al₂O₃ nanofluid and its volume concentration on the flow and heat transfer characteristics of Y-shaped rib microchannels is also studied.At the same time,for comparison,smooth and rectangular truncated rib microchannels were established by referring to the literature,and the flow and heat transfer characteristics of the three kinds of microchannels were compared.Studies have shown that（1）The Y-shaped rib microchannel has the strongest heat transfer performance and comprehensive thermal performance among the three types of microchannels;（2）The Y-shaped rib can generate strong horizontal and vertical vortices and violent vortices in the microchannels The heat transfer is enhanced,but the flow resistance is increased;（3）The Y-shaped rib arm angleαmainly affects the secondary flow intensity of the Y-shaped rib microchannel.Asαdecreases,the secondary flow intensity and the area of influence increase.A larger temperature gradient can be obtained at the wall;（4）The infinite arm length(1/mainly affects the longitudinal vortex intensity and area behind the Y-shaped rib.With the increase of(1/,the vortex intensity and area are simultaneously Increase;（5）In the range of Re=200～800,the Y-shaped rib withα=60°,(1/=1 and arm thickness Wr=0.04～0.06mm is the best;（6）The same working condition,The Y-shaped rib microchannel with a volume concentration of 4%Al₂O₃ nanofluid has the best heat transfer performance.