Impact on Heat Transfer Rate Due to an Extended Surface on the Passage of Microchannel Using Cylindrical Ribs with Varying Sector Angle

In this paper, the impact of an extended surface on the passage of a microchannel using cylindrical ribs with variable sector angles on heat transfer rate is presented using computer simulation. Extended surfaces in the form of cylindrical ribs of varying sector angles in the passage of microchannel in a staggered manner have been designed. The sidewalls of a new kind of microchannel incorporating five distinct ribs with sector angles ranging from 45° to 80° have been analyzed. Ansys Fluent workbench software has been exploited to simulate this novel design of a microchannel heat sink. A three-dimensional heat transfer and fluid flow model of the microchannel heat sink (MCHS) was developed, and the fluid and solid regions were discretized in very fine meshes. All CFD simulations were performed for Reynolds numbers between 100 and 900. Nusselt numbers are varied in the following ranges: 6.93 to 13.87, 6.93 to 14.38, 6.93 to 17.80, 7.15 to 27.86, and 7.20 to 37.38 at sector angles of 45°, 50°, 60°, 70°, and 80°, respectively. It is concluded that the Nusselt number is strongly influenced by the Reynolds number. At an angle of 80°, the maximum friction factor and pumping power requirements were observed. Additionally, a 45° angle has been proven to be the minimal friction factor and pumping power requirement. It is revealed that the THPP has all values larger higher than 1. At angles of 80° and 45°, the maximum and minimum values of THPP have been discovered, respectively. In addition, thermo-hydraulic performance parameters have been evaluated, which are greater than one for all sector angles.