Experimental Study on Heat Transfer and Flow Characteristics of Air Cooling through Cross-flow Microchannel Heat Exchanger

Air-side heat transfer and flow characteristics were studied through an air-to-deionized water cross-flow serpentine microchannel heat exchanger during air cooling. In the single phase, twenty distinct operating conditions were maintained within the range of air and deionized water-side Reynolds number 283 ≤ Rea ≤ 1384 and 105 ≤ Rew ≤ 159 respectively, retaining the constant inlet temperatures of both fluids (Ta,i = 38 +/-0.5°C and Tw,i = 9 +/-0.5°C). Heat transfer and fluid flow key parameters were evaluated from experimental data. Heat balance performance was observed within 4% throughout the experiment, and major thermal resistance was found in the air-side, ranging from 89% - 94% of overall thermal resistance. The effects of Rew and Re a on air-side Nusselt number (Nua), Colburn factor (j a), friction factor (fa), and other parameters were examined, and general correlations were achieved. The Nua-Rea-Pr a relationship of the current study is compared to other correlations, and several recommendations are proposed.