Three-dimensional assessment of thermal-hydraulic behaviour in heat exchangers fitted by wavy annular fins

Abstract

In this study, numerical studies to clarify the influence of wave number and amplitude on thermal-flow behavior of wavy annular finned-and-tube heat exchangers are described. For a range of Reynolds number from 4400 to 14300, the influence of wave amplitude, 1.5 ? A ? 4.5 mm, and wave numbers, 2 ? Nw ? 6, on forced convection heat transfer was examined. It was revealed that the wave amplitude and number have an impact on the heat flux, Colburn factor, and friction factor. The wavy annular-fins with a 3 mm amplitude and Nw = 4 waves obtained the highest values at all Reynolds numbers in terms of the overall performance criterion (j/f1/3).