Numerical study of wavy shape microchannel with disruptive structures based on thermodynamics and pumping power

Abstract three dimensional study has been carried out to find a copper based novel micro heatsink for efficient cooling of miniature electronic devices. The disruptive units such as waviness, rectangular cavities, and diamond ribs, are considered to augment the heat transfer. Three different microchannels are taken as straight channel with rectangular cavity (SRC), wavy channel with rectangular cavity (WRC), and wavy channel with rectangular cavity and diamond rib (WRCD) are analyzed across Reynolds numbers range from 66 to 530 using water as the working fluid. Performance of heat sinks is meticulously evaluated for each configuration based on Thermal performance (TP) and Entropy generation number (EGN). The study explicitly explores the role of disruptive structure in creating the recirculation zone, wall shear stress, local heat transfer coefficients, vorticity, and dean vortices in minimizing entropy generation. Moreover, the change in flow characteristic with geometrical parameters such as diamond rib's length, transverse and longitudinal rib position, and waviness amplitude of channel are identified with improve in TP and EGN. Microchannel with waviness, rectangular cavity and diamond rib emerges as the optimal design among various channel configurations, with the highest TP being 1.44 and the lowest EGN being 0.61. This also reveals that peak local heat transfer aligns with regions of maximum wall shear stress. The addition of a diamond rib enhances the strength of the Dean vortices in the downstream of the channel, whereas shifting the rib away from the cavity center in either direction leads to a reduction in TP.