Parametric study of heat transfer performance including entropy generation of microchannel heat sink with fan cavity and different rib structure

Abstract

This numerical study investigates the simultaneous application of axial wall conduction effect and entropy generation minimization as two principles to identify heat transfer performance in a microchannel heat sink with fan cavity and ribs. In this conjugate analysis, three different materials for a microchannel heat sink considered are silicon, aluminium, and copper. In addition to the fan cavity (F), effects of different rib configurations arranged symmetrically inside the fan cavity, that is, backward triangle rib (FB), rectangular rib (FR), forward triangle rib (FF), and diamond rib (FD) with Reynolds numbers ranging from 136 to 588 are studied. The comparative study between silicon and copper in terms of local wall and bulk fluid temperatures, increment in solid wall to fluid thermal conductivity ratio within the range (247.07 < ksf < 669.44), local Nusselt number (Nu x), axial conduction number (M), and entropy generation number ( Ns, a) were furnished and examined. Structural optimization is performed on diamond rib configuration geometrical parameters to observe entropy generation number and wall conduction effects trend as thermal performance is greatly improved to 2.49, at the lowest Ns, a to 0.31 at Re 391.47, with copper in the back to back cavities case. However based on the numerical results, comparative importance of axial wall conduction effect consideration in the present design of microsink, silicon is showing best results in overcoming at Re 588.4, consistently in all optimization cases.

Numerical investigation of heat transfer enhancement in microchannel heat sink with fan cavities using secondary channels and ribs

“…The relative length of cavity γ ( = L fc /L ) is defined as the ratio of the length of the FC over the length of the microchannel. Length of FC considered are 350, 400, 450, and 500 µm and constant parameters length of the microchannel is considered 10,000 µm, width of fan cavity W fc = 75 µm based on our previous works [26, 27]. Supplementary Figure 9(a) represents the influence of cavity length, and orientation when SCs were attached to it, on Nusselt number variation with Re.…”

“…Kumar et al 24,25 numerically studied SC impact on mechanisms of greater fluid mixing, boundary layer thinning, and strengthening of dean vortices. Bala Subrahmanyam et al's 26,27 numerical simulations gave adequate insight into heat transfer enhancement with fan cavity and various rib structures. Furthermore, parametric analysis explored the influence of axial wall conduction effects on overall performance.…”