Turbulent forced convection flow inside inward‐outward rib corrugated tubes with different rib‐shapes

Abstract

AbstractThe thermal and hydrodynamic behaviors of forced convection turbulent flow inside the corrugated tube are investigated numerically. The ribs of corrugated tube are distributed in inward‐outward arrangement simultaneously and alternately (referred as IOCT). Three roughness shapes of the corrugated tube are examined; rectangular, semicircular, and trapezoidal ribs. The computational model is validated through comparison with the predicted results with correlated and experimental ones of related works. The performance of IOCT is compared thermally and hydrodynamically with that of the inward‐rib corrugated tube (ICT), outward‐rib corrugated tube (OCT) and smooth tubes. The results reveal that the heat is exchanged effectively by employing IOCT than utilizing OCT but with extra pumping power losses. At the maximum Re, it is found that the heat transfer of IOCT is 17.7% higher than that of OCT, and utilizing IOCT instead of ICT results in a reduction of friction factor by about 27.2%. Also, IOCT exhibits a lower friction factor and pressure drop penalty than that imposed by ICT. Also, roughness shapes have an insignificant effect on the thermal and hydrodynamic performances of IOCT for the same rib geometrical parameters. Furthermore, the influence of variation pitch‐to‐diameter ratio is also examined for various rib shapes of IOCT.