Pressure Drop and Heat Transfer Characteristics in a Microchannel with Pin-Fins

Abstract

Pin-fin heat sinks are now considered one of the possible solutions for the thermal management of small-scale devices requiring high heat dissipation rates. Pin-fins with fixed diameters, different heights and spacing were numerically investigated in the current study for a range of Re=200-1000. The micro-channel cross-section with pins at the bottom surface measures 55 mm in length and has a cross-sectional area of 1 mm x 1 mm. The fin height ranges from 0.2 to 0.8 mm and the distance between pin-fins ranges from 3-6 mm. The fins had a circular cross section 0.25 mm in diameter. The Box-Behknen method was used to determine the number of numerical runs based on the parametric range of pin height and spacing and the Re number. Input data and corresponding outputs were presented using the Genetic Aggregation Response Surface Methodology. An optimum pin height and spacing in terms of heat transfer rates was obtained. It has been observed that at the optimum design, considering the highest Performance Evaluation Criteria (PEC) value the microchannel with pin-fins, can provide an enhancement of 364% in heat transfer rates compared to the microchannel without pins, while the corresponding increase in pressure drop reaches up to 162%. Correlations are proposed for heat transfer and pressure drop calculations able to predict the numerical results mostly within 10%.