Small scale model for CFD validation in DAF application

J. Hague*, C. T. Ta, M. J. Biggs, J. A. Sattary

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)


A laboratory model is used to measure the generic flow patterns in dissolved air flotation (DAF). The Perspex model used in this study allows the use of laser Doppler velocimetry (LDV), a non-invasive, high-resolution (±2 mm s-1) laser technique of flow velocity measurement. Measurement of flow velocity in the single-phase situation was first carried out. Air-saturated water was then supplied to the tank and measurements of bubble velocity in the two-phase system were made. Vertical flow re-circulation was observed in the flotation zone. In the bottom of the flotation zone (near the riser) secondary flow re-circulation was observed, but only in the two-phase system. Another phenomenon was the apparent movement of flow across the tank width, which may be due to lateral dispersion of the bubble cloud. Data from preliminary computational fluid dynamics (CFD) models were compared against this measured data in the case of the single-phase system. The CFD model incorporating a k-ε model of turbulence was found to give closer agreement with the measured data than the corresponding laminar flow model. The measured velocity data will be used to verify two-phase computational fluid dynamics (CFD) models of DAF.

Original languageEnglish
Pages (from-to)167-173
Number of pages7
JournalWater Science and Technology
Issue number8
Publication statusPublished - 1 Apr 2001


  • Computational fluid dynamics (CFD)
  • Dissolved air flotation (DAF)
  • Flow measurement
  • Laser Doppler velocimetry (LDV)
  • Modelling
  • Two-phase

ASJC Scopus subject areas

  • Environmental Engineering
  • Water Science and Technology


Dive into the research topics of 'Small scale model for CFD validation in DAF application'. Together they form a unique fingerprint.

Cite this