Numerical investigation of thermo-hydraulic performance utilizing clove-treated graphene nanoplatelets nanofluid in an annular passage with perforated curve fins

The use of fins is critical for improving the heat transmission of annular passages. This paper numerically investigated the thermo-hydraulic performance of finned annular conduits with varying hole numbers (0–16) and configurations. The clove-treated graphene nanoplatelets/distilled water (CGNP/DW) nanofluid 0.1 wt% was employed as the working fluid. Moreover, ANSYS FLUENT was utilized to study the flow characteristics with Reynolds numbers ranging from 611 to 10,389. Five curve fins were mounted on the inner wall of an annular conduit with an isolated outer surface and a constant heat flux inner pipe. According to the results, the eight-hole configuration obtained the highest performance evaluation criteria (PEC) value. This design offered advantages for use in laminar and transitional regions with Reynolds numbers lower than 4277, where all the PEC values were higher than 1. Furthermore, CGNP nanofluid improved the heat transfer coefficient by 11.87% and 11.43% for the curve fin conduit with eight holes and smooth pipe, respectively, with a negligible rise in pressure drop. The maximum heat transfer coefficient enhancement attained was 49.88% using the curve fin conduit with eight holes and CGNP nanofluid. Lastly, the curve fin conduit with eight holes was recommended with a heat transfer coefficient lower than 2000 W/m2K, where either CGNP nanofluid or DW was employed.