Powder Technology, Vol.380, 475-485, 2021
The effect of magnetic field on the twisted porous ribs with various porous layers and pitches: The first and second laws of thermodynamics study with two-phase approach
Heat sinks are always in the center of electronic cooling researchers' attention. Microchannels are utilized in electronic cooling devices owing to their increased surface and better thermal performance than that of normal heat sinks. In this numerical investigation, the first and second laws of thermodynamics impact of twisted porous ribs on the microchannel are studied. The effects of the Reynolds number, the Hartman number, and the volume fraction of nanoparticles are investigated. The range of the dimensionless number for the Hartmann number and the Reynolds number is 0 to 20 and 250 to 1000, respectively. All types of microchannel in this study consist of clear microchannels in two groups; group one (No. 1, 2 and 3) and group two (No. 4, 5, and 6). The obtained results show that at the end of each porous rib, the reported parameters depict a decrease. Twisted porous ribs cause a significant decrease in the expanding thermal boundary layer. Also, the microchannel with triple-layer porous ribs (No. 3) exhibits considerable performance in the entropy generation. Finally, since group one has a double pitch, it has the better thermal performance and increasing the Hartmann number is one of the reasons for the increasing velocity gradient near the microchannel wall and friction factor. (C) 2020 Elsevier B.V. All rights reserved.