Heat Transfer in Trapezoidal Microchannels of Various Aspect Ratios
نویسندگان
چکیده
Heat transfer in the thermal entrance region of trapezoidal microchannels is investigated for hydrodynamically fully developed, single-phase, laminar flow with no-slip conditions. Three-dimensional numerical simulations were performed using a finite-volume approach for trapezoidal channels with a wide range of aspect ratios. The sidewall angles of 54.7 and 45 are chosen to correspond to etch-resistant planes in the crystal structure of silicon. Local and average Nusselt numbers are reported as a function of dimensionless length and aspect ratio. The effect of Prandtl number upon the thermal entrance condition is explored. The fully developed friction factors are computed and correlated as a function of channel aspect ratio. Correlations are also developed for the local and average Nusselt numbers in the thermal entrance region as a function of a dimensionless axial length variable. 2009 Elsevier Ltd. All rights reserved.
منابع مشابه
Three dimensional numerical study on a trapezoidal microchannel heat sink with different inlet/outlet arrangements utilizing variable properties nanofluid
Nowadays, microchannels as closed circuits channels for fluid flow and heat removal are an integral part of the silicon-based electronic microsystems. Most of previous numerical studies on microchannel heat sinks (MCHS) have been performed for a two-dimensional domain using constant properties of the working fluid. In this study, laminar fluid flow and heat transfer of variable properties Al2O3...
متن کاملA NUMERICAL STUDY OF SINGLE-PHASE FORCED CONVECTIVE HEAT TRANSFER WITH FLOW FRICTION IN MICROCHANNELS (RESEARCH NOTE)
Three-dimensional simulations of the single-phase laminar flow and forced convective heat transfer of water in microchannels with small rectangular sections having specific hydraulic diameters and distinct geometric configurations were investigated numerically. The numerical results indicated that the laminar heat transfer was to be dependent upon the aspect ratio and the ratio of the hydraulic...
متن کاملThe numerical study of heat transfer of water-TiO2 nanofluid in the triangular microchannels with semiattached and offset mid-truncated rib,s
In this numerical study the the heat transfer and laminar nanofluid flow in the three-dimensional microchannels with triangular cross-section is simulated. For increase the heat transfer from the walls of the channel, semiattached & offset mid- truncated rib,s Placed in the canal, and the tooth geometry and the impact is studied. In this study, the water is base fluid, and the influence of th...
متن کاملExperimental Investigation of Boiling and Condensation Heat Transfer of a two Phase Closed Thermosyphon
In this paper the heat transfer characteristics of a two-phase closed thermosyphon over a wide range of heat transfer rates, system pressure, aspect ratios and filling ratios were studied. The experiments focused on the boiling and condensation heat transfer characteristics of the thermosyphon. The experimental boiling and condensation heat transfer coefficients inside the thermosyphon were com...
متن کاملA numerical investigation of heat transfer and pressure drop in a novel cylindrical heat sink with helical minichannels
This study numerically investigated heat transfer and fluid flow characteristics in a novel cylindrical heat sink with helical minichannels for the laminar flow of fluid with temperature-dependent properties. A finite volume method was employed to obtain the solution of governing equations. The effects of helical angle, channel aspect ratio, and Reynolds number, which were regarded as main para...
متن کامل