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 degrees and 45 degrees 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.


Microchannel, thermally developing, liquid cooling, heat sink, trapezoid

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J. P. McHale and S. V. Garimella, “Heat Transfer in Trapezoidal Microchannels of Various Aspect Ratios,” International Journal of Heat and Mass TransferVol. 53, pp. 365-375, 2010. .