The application of two-phase model to assess the nanofluid entropy generation in serpentine and double-serpentine heatsinks

Abstract

The frictional and thermal entropy generation rates (S˙fr and S˙th) of two heatsinks with serpentine (Conf. A) and double serpentine (Conf. B) channels with water/silver Nano fluid (NF) were numerically investigated. The results demonstrated that the augmentation of nanoparticle concentration (φ) from 0% to 1% leads to decrease S˙th by 6.36% and 3.51% in Conf. A and Conf. B, respectively, for Re=500. The escalation of Re from 500 to 2000 increases this percentages to 9.93% and 7.51%, respectively. Also, the increase of Re from 500 to 2000 at a constant φ reduces S˙th by 63% and 68% in Conf. A and Conf. B, respectively, due to enhance the heat dissipation. Moreover, the increasing of φ from 0% to 1% decreases S˙fr by 12.41% in both configurations and at four studied Res due to decreasing the NF velocity. Besides, the escalation of Re from 500-2000 intensifies S˙fr nearly by 62% and 67% in Conf. A and Conf. B, respectively. The entropy contour plots reveal that S˙fr intensifies near the turn regions of the serpentine channels. Also, S˙th is intensifies at the entrance of heatsink channels due to the high temperature gradient at these points. Conversely, S˙fr escalates at the exit of the channels due to intensification of the vortexes formed at the turn parts and along the serpentine channel.