In this study, the fluid flow and heat transfer behavior in a novel circular wavy microchannel design is numerically examined and compared with a sinusoidal wavy microchannel. The numerical studies were carried out in the Reynolds number range of 100–300 under a constant heat flux wall boundary condition. The sinusoidal profile has a continuously varying curvature, which peaks at the crests and troughs, and diminishes to naught at each section at the middle of adjacent crests and troughs. On the other hand, the circular profile has a curvature constant in magnitude (and alternating in direction). Heat transfer in wavy microchannels is enhanced by vortex flow induced by centrifugal instability, which in turn depends on the curvature of fluid channel profile. The sinusoidal wavy microchannel has a curvature continuously varying in a large range results in large fluctuations of Nusselt number, while the Nusselt number in the circular channel has smaller fluctuations. Hence, heat transfer performance of the circular wavy microchannel is higher than that of the sinusoidal wavy microchannel. Velocity vectors, velocity contours, and temperature contours are presented to aid the explanation of hydrodynamic and heat transfer characteristics of fluid flow in the novel circular wavy microchannels. The Nusselt number and pressure drop along the channel are also compared with the sinusoidal wavy microchannel using a performance factor.
In this study, hydrothermal characteristics in a circular wavy microchannel (CWMC) design under laminar flow conditions with uniform heat flux is numerically studied. Parametric studies in an innovative CWMC design were carried out at various wave amplitudes, wavelengths and aspect ratios. Three dimensional numerical study was performed in the Reynolds number (Re) range from 100 to 300 with uniform heat flux (50 W/cm2) applied at bottom of the channel, treating copper as channel material and water as working fluid. The obtained results were compared to sinusoidal wavy microchannel (SWMC).The results showed that heat transfer and fluid flow characteristics were significantly influenced by wave amplitude, wavelength and aspect ratio. Velocity vectors and contours were presented to understand the heat transfer and fluid flow characteristics. Stream-wise local Nusselt number, overall performance factor, span-wise velocity and temperature variation are also presented. It is concluded that CWMC with higher wave amplitude, smaller wave length and smaller aspect ratio gives higher heat transfer augmentation with corresponding pressure drop penalty.
Wavy microchannels have been shown to possess improved heat transfer capabilities because of greater fluid mixing and boundary layer thinning. In this study, fluid flow and heat transfer characteristics of circular wavy microchannels with tangentially branched secondary channels, were numerically investigated. Its heat transfer and fluid flow characteristics were compared with other specific wavy microchannel geometries. Three-dimensional numerical studies were carried out in the Reynolds number range of 100–300 with uniform heat flux wall boundary condition, using Ansys Fluent commercial software. Validation of the model was done with experimental data from literature. Circular wavy microchannels, owing to constant curvature, lead to nearly constant Dean vortices strength. The tangential branched secondary channels helped in further effective fluid mixing and in reinitializing the boundary layer. These phenomena had significant effect on its heat transfer and fluid flow behavior. Circular wavy microchannels with tangentially branched secondary channels, having secondary channel width to primary channel width ratio (ω) equal to 0.25, showed higher overall performance than other designs considered in the present study. Velocity vectors, velocity and temperature contours are presented to explain the fluid flow and heat transfer characteristics. It is observed that circular wavy microchannels with tangentially branched secondary channel design (ω = 0.25) gives 39.36% higher Nusselt number with 21% increased pressure drop as compared to sinusoidal wavy microchannel design. The overall performance factor of circular wavy microchannel with tangentially branched secondary channel design (ω = 0.25) is higher in the Reynolds number range of 100–250 than all other designs considered in this study.
Microchannel (MC) heat sinks have been extensively researched and used for thermal management. Wavy MC heat sinks and wavy MC with 45 o branched secondary channel heat sinks are shown in the literature to have superior heat transfer enhancement capabilities than straight MCs, with more pressure drop as penalty. To minimize the pressure drop, a new design is introduced in this paper by altering the wavy MC, with tangential branched secondary channels, at peaks and troughs of the wavy MC. Numerical investigation is carried out in the Reynolds number range of 100 to 300 with constant heat flux wall boundary condition. A simple parametric study on the secondary channel width is also carried out. Wavy MC with TBSC, having secondary channel width as half of the primary channel, is found to have the best combination of heat transfer and pressure drop performance, compared with wavy MC heat sinks and wavy MC with 45 o branched secondary channel heat sinks. The flow phenomenon that leads to such performance is carefully analyzed and discussed in detail in this paper.
In the current study, computational analysis of the hydrothermal behavior of fluid flow in straight microchannels (MCs) with base triangular and wavy profile designs was conducted and the results were compared with that of straight MCs. The computational study was conducted in the 100–300 Reynolds number (Re) range. According to computational analysis, the thickness of the boundary layer grows as the fluid moves through straight MC, resulting in lower heat dissipation. Continual thinning and thickening of the boundary layer is seen to form in straight MC with triangular base and wavy profile designs. The fluid passing through the MC material can transfer heat more effectively as a result. Additionally, in straight MC with base wavy profiles designs, it was observed that there were more Dean vortices, reduction in stagnation zones, and lowering of channel base temperature. From the current study, it was noticed that straight MC with base wavy profiles designs showed higher heat transfer (0.5% to 21.14%), lower pressure drop (18.65% to 14.25%) compared to straight MC at Re range from 100 to 300, and higher overall performance factor compared to other designs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.