Effect of flow irregularity on oscillatory boundary layer flow

Mahesa Bhawanin, Thomas O'Donoghue, Dominic Alexander Van Der A, Jan S Ribberink

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The paper reports on new oscillatory flow tunnel experiments in which detailed measurements have been made of boundary layer velocities for full-scale regular and irregular oscillatory flows over sand-rough and gravel-rough fixed beds. The irregular flows were generated by amplitude modulation of the corresponding regular flows, to give same free-stream urms and same velocity and acceleration skewness. The experimental setup is described and initial results relating to flow structure, turbulence and bed shear stress are presented. Results presented for boundary layer development, turbulence intensity, turbulent stress and log-law-based estimates of bed shear stress suggest that the hydrodynamics within a flow half-cycle are largely independent of the previous flow half-cycle, at least close to the bed where the presented results have focused. Time-history effects are not entirely absent however, especially higher up from the bed. More detailed analysis is needed to elucidate further.
Original languageEnglish
JournalCoastal Engineering Proceedings
Volume34
DOIs
Publication statusPublished - 2014

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boundary layer
oscillating flow
bottom stress
shear stress
turbulence
flow structure
skewness
sand and gravel
tunnel
hydrodynamics
effect
history
experiment

Keywords

  • oscillatory flow
  • boundary layer
  • turbulence
  • flow tunnel
  • laboratory experiments

Cite this

Effect of flow irregularity on oscillatory boundary layer flow. / Bhawanin, Mahesa; O'Donoghue, Thomas; Van Der A, Dominic Alexander; Ribberink, Jan S.

In: Coastal Engineering Proceedings, Vol. 34, 2014.

Research output: Contribution to journalArticle

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