Optimization of Microchannel with Dovetail Ribs at Sidewalls for Maximum Convective Heat Transfer and Minimum Pressure Drop with Conjugate Heat Transfer

The present two - dimensional numerical study investigates one of the passive techniques to increase heat transfer in micro-scale devices. The microchannel used in present study is equipped with side-wall dovetail ribs which creates flow disturbance and thus enhances overall heat transfer. Optimized design of microchannel has been the prime aim of this work. The effects of various geometrical parameters viz. Amplitude (A), Pitch of Ribs (L) and Rib angle (a degrees) on Heat Transfer and Pressure drop are analysed for different combinations of these parameters. Values of parameters are taken as: A (0.05, 0.075, 0.1) mm, L (1, 2, 4, 8) mm and a (30 degrees, 45 degrees, 60 degrees). The length of channel is 8 mm and width or characteristic dimension is 1.2 mm. In total, 36 numerical simulations are performed over possible combinations of A, L and a with water as working fluid. All simulations are performed at Re = 400 and comparison is made. The problem is of Conjugate-Heat Transfer with heat flux applied to both walls is 10(6) W/m(2) on both sides. Numerical Simulations are performed on commercially available software package ANSYS Fluent 17.1 (R). The minimum pressure Drop obtained for (L, a, A) = (8, 30 degrees, 0.05) is 67 Pa while that for rectangular channel of identical characteristic dimensions is 57 Pa, However Nusselt number obtained is around 17 i.e. 1.25 times higher than that of rectangular channel with developing flow. Optimized result obtained for maximum heat transfer and minimum pressure drop is (L, a, A) = (8, 30 degrees, 0.05) using TOPSIS algorithm.