Effect of Dimpled Rib with Arc Pattern on Hydrothermal Characteristics of Al2O3-H2O Nanofluid Flow in a Square Duct

The present work is concerned with the experimental analysis of thermal and hydraulic performance Al2O3−H2O nanofluid flow in dimpled rib arc pattern a square duct. Alumina consists nanoparticles having size 30 nm. Reynolds number Renum studied duct range from 5000 to 26,000. nanoparticle volume fraction (ϕnp) ranges 1.5% 4.5%, ratio dimpled-arc-rib-height print-diameter HAD/Pd 0.533 1.133, dimpled-rib-pitch height PAD/HAD 3.71 6.71 angle (αAD) 35° 65°. Al2O3−H2O-based values Nusselt Nurs friction factor frs are higher comparison pure water. ribs significantly improved thermal-hydraulic investigated test section. concentration print diameter 0.933, relative 4.64 55° deliver maximum magnitude heat transfer rate. value parameters was found be 1.23 for investigated. Correlations Nurs, ηrs have been developed selected operating geometric parameters.