Geometric optimization of pin fins for enhanced cooling in a microchannel heat sink

Abstract

Microchannel heat sinks (MCHS) are widely used for active cooling of electronics. Considerable enhancements in thermal performance are achievable by finning the MCHS to extend heat transfer area and create local flow turbulence. Yet, the literature lacks multi-objective geometric optimizations of the fin design. This study optimizes the geometry of tapered squared cross-section pin-fins in a square base MCHS, where the fins’ dimensions are manipulated in terms of their area, clearance, tapering width, and tapering height ratios (AR, CR, TWR, and THR, respectively). The optimization is based on an experimentally validated computational model. The performance is analyzed for 256 finned MCHS configurations, compared with a reference unfinned MCHS. The results show a high dependency of thermal performance on AR and THR, where the hydraulic performance is more affected by AR. The executed genetic optimization procedure demonstrated non-dominated designs with thermal resistances ranging between 0.00078 and 0.0033 K/W and pressure losses ranging between 0.229 and 2.64 kPa. By considering these two performance metrics to be equally important, a balanced design with AR, CR, TWR, and THR of 0.284, 5.52 × 10−5, 0.6, and 1.0 was identified, which brings down the thermal resistance and pressure losses to only 0.000983 K/W and 0.7133 kPa, respectively.