Design Optimization of Interrupted Microchannel Heat Sink with Ellipsoidal Ribs in the Transverse Microchambers
A three-dimensional numerical model of the interrupted microchannel heat sink is presented to study the effects of pressure drop and heat transfer characteristics due to various dimensions of ellipsoidal ribs in the transverse microchambers. Numerical simulation is performed considering entrance effect, conjugate heat transfer, viscous heating and temperature-dependent thermo-physical properties. For the first part of the optimum analysis, the ellipsoidal rib length and width with the constant rib cross-sectional area are chosen as the geometry variables to find their optimum dimensions. The effect of such ribs on temperature distribution, velocity contour and pressure distribution and, further the pressure drop and heat transfer characteristics are examined. The result shows that the ribs in the transverse microchambers can effectively prevent the decline of heat transfer coefficient along the flow direction. Secondly, the average friction factor and Nusselt number of such microchannel heat sinks have been studied. Results show that for Reynolds number ranging from 132 to 664, there is a 25-46% increase in the Nusselt number for the interrupted microchannel heat sinks with ellipsoidal ribs, while the friction factor increased by 20-47%, comparing with the plain straight microchannel heat sink. Finally, based on the performance evaluation criteria, the optimal dimension parameters of the ellipsoidal ribs are obtained in principle.
Keywords - Microchannel Heat Sink, Interrupted Microchannel, Numerical Simulation, Pressure Drop, Heat Transfer, Performance Evaluation Criteria