Experimental investigation of the heat transfer and flow characteristics of microchannels with microribs

The single-phase heat transfer and flow characteristics of microchannels with microribs were investigated experimentally in this paper. Based on a smooth rectangular microchannel (MC-S), rectangular microchannels with rectangular ribs on one side (MC-OSR) and both sides (MC-BSR) were proposed. The effects of the volumetric flow rate and inlet temperature on the Nusselt number and friction factor were analyzed. Five positions were assigned evenly in the flow direction at the wall to measure the temperature and determine the wall temperature distribution. The results showed that the Nusselt number increased as the volumetric flow rate and inlet temperature increase. The friction factor decreased with increasing inlet temperature. The thermal performance index of the MC-OSR was higher than those of the MC-BSR and MC-S, which reflected the superior heat transfer performance of the MC-OSR. The wall temperature was nonlinearly distributed in the flow direction. The amplitude of the temperature difference gradually decreased. Compared to the MC-S, the entrance effects of the MC-OSR and MC-BSR were more obvious mainly due to the presence of ribs.