Groove-induced changes of discharge in channel flows

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)297-333
Journal / PublicationJournal of Fluid Mechanics
Volume799
Early online date23 Jun 2016
Publication statusPublished - 25 Jul 2016
Externally publishedYes

Abstract

The changes in discharge in pressure-driven flows through channels with longitudinal grooves have been investigated in the laminar flow regime and in the turbulent flow regime with moderate Reynolds numbers (Re2H ≈ 6000) using both analytical and numerical methodologies. The results demonstrate that the long-wavelength grooves can increase discharge by 20 %-150 %, depending on the groove amplitude and the type of flow, while the short-wavelength grooves reduce the discharge. It has been shown that the reduced geometry model applies to the analysis of turbulent flows and the performance of grooves of arbitrary form is well approximated by the performance of grooves whose shape is represented by the dominant Fourier mode. The flow patterns, the turbulent kinetic energy as well as the Reynolds stresses were examined to identify the mechanisms leading to an increase in discharge. It is shown that the increase in discharge results from the rearrangement of the bulk fluid movement and not from the suppression of turbulence intensity. The turbulent kinetic energy and the Reynolds stresses are rearranged while their volume-averaged intensities remain the same as in the smooth channel. Analysis of the interaction of the groove patterns on both walls demonstrates that the converging-diverging configuration results in the greatest increase in discharge while the wavy channel configuration results in a reduction in discharge.

Research Area(s)

  • drag reduction, flow control, turbulent flows

Citation Format(s)

Groove-induced changes of discharge in channel flows. / Chen, Yu; Floryan, J. M.; Chew, Y. T.; Khoo, B. C.

In: Journal of Fluid Mechanics, Vol. 799, 25.07.2016, p. 297-333.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review