Advertisement

Journal of Hydrodynamics

, Volume 30, Issue 4, pp 651–656 | Cite as

Dominant factor and incremental depth formula for self-aerated flow in open channel

  • Rui-di Bai (白瑞迪)
  • Fa-xing Zhang (张法星)
  • Wei Wang (王韦)
  • Shanjun Liu (刘善均)
Articles
  • 4 Downloads

Abstract

The presence of air in open channel flows will increase the bulk of the flow, and is of great importance in the design of spillway and chute sidewalls. Hydraulics in the developed region is investigated in this paper systematically by a series of model and prototype investigations. It is verified that the velocity in the aeration region is the dominant factor. For the flow with an identical velocity but a different flow depth, the air concentration distributions are nearly the same. From the theory based on the formation of drops on the surface by the turbulent liquid jets and the vortex deformation, a formula to calculate the incremental depth is obtained by best correlating the model and prototype investigations. The formula is reasonable with less mean error than those obtained by other methods, which could recommended for the use in engineering designs.

Key words

Aerated flow aeration incremental depth unaerated black water aeration flow depth 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    Kramer K., Hager W. H., Minor H. E. Development of air concentration on chute spillways [J]. Journal of Hydraulic Engineering, ASCE, 2006, 132(9): 908–915.CrossRefGoogle Scholar
  2. [2]
    Chanson H. Bubble entrainment, spray and splashing at hydraulic jumps [J]. Journal of Zhejiang University-Science A, 2006, 7(8): 1396–1405.CrossRefGoogle Scholar
  3. [3]
    Chanson H. Turbulent air-water flows in hydraulic structures: Dynamic similarity and scale effects [J]. Environmental Fluid Mechanics, 2009, 9(2): 125–142.MathSciNetCrossRefGoogle Scholar
  4. [4]
    Baylar A., Bagatur T. Experimental studies on air entrainment and oxygen content downstream of sharp-crested weirs [J]. Water and Environment Journal, 2006, 24(4): 210–216.CrossRefGoogle Scholar
  5. [5]
    Wilhelms S. C. Gas transfer, cavitation, and bulking in self-aerated spillway flow [J]. Journal of Hydraulic Research, 2005, 45(4): 532–539.CrossRefGoogle Scholar
  6. [6]
    Steven C., Gulliver J. S. Bubbles and waves description of self-aerated spillway flow [J]. Journal of Hydraulic Research, 2008, 46(3): 420–423.CrossRefGoogle Scholar
  7. [7]
    Chanson H. Compressibility of extra-high-velocity aerated flow: A discussion [J]. Journal of Hydraulic Research, 2004, 42(2): 213–215.CrossRefGoogle Scholar
  8. [8]
    Pfister M., Lucas J., Hager W. H. Chute aerators: Pre aerated approach flow [J]. Journal of Hydraulic Engineering, ASCE, 2011, 137(11): 1452–1461.CrossRefGoogle Scholar
  9. [9]
    Pfister M., Hager W. H. Self-entrainment of air on the stepped spillways [J]. International Journal of Multiphase Flow, 2011, 37(2): 99–107.CrossRefGoogle Scholar
  10. [10]
    Chanson H. Hydraulics of aerated flows: qui pro quo? [J]. Journal of Hydraulic Research, 2013, 51(3): 223–243.CrossRefGoogle Scholar
  11. [11]
    Chanson H. Air-water flow measurements with intrusive phase-detection probes. Can we improve their interpretation? [J]. Journal of Hydraulic Engineering, ASCE, 2002, 128(3): 252–255.CrossRefGoogle Scholar
  12. [12]
    Vidal L. E. O., Rodriguez O. M. H., Estevam V. et al. Experimental investigation of gravitational gas separation in an inclined annular channel [J]. Experimental Thermal and Fluid Science, 2012, 39(5): 17–25.CrossRefGoogle Scholar
  13. [13]
    Toombes L., Chanson H. Air-water mass transfer on a stepped waterway [J]. Journal of Environmental Engineering, 2005, 131(10): 1377–1386.CrossRefGoogle Scholar
  14. [14]
    Girgidov A. D. Self-aeration of open channel flow [J]. Power Technology and Engineering, 2012, 45(5): 351–355.Google Scholar
  15. [15]
    Zhang F. X., Xu W. L., Zhu Y. Q. Experimental study on formation of air bubbles in self-aerated open channel flows [J]. Journal of Hydraulic Engineering, 2010, 41(3): 343–347(in Chinese).Google Scholar
  16. [16]
    Cao L. K., Li D. X., Chen H. et al. Spatial relationship between energy dissipation and vortex tubes in channel flow [J]. Journal of Hydrodynamics, 2017, 29(4): 575–585.CrossRefGoogle Scholar
  17. [17]
    Deng J., Wei W. R., Xu W. L. et al. Experimental study on air frequency in self-aerated flows [J]. Water Management, 2015, 168(4): 1–9.CrossRefGoogle Scholar
  18. [18]
    Smolentsev S., Miraghaie R. Study of a free surface in open-channel water flows in the regime from “weak” to “strong” turbulence [J]. International Journal of Multiphase Flow, 2005, 31(8): 921–939.CrossRefMATHGoogle Scholar
  19. [19]
    Aras E., Berkun M. Effects of tail water depth on spillway aeration [J]. Water Statistika of Afrika, 2012, 38(2): 307–312.Google Scholar
  20. [20]
    Wei W., Deng J., Zhang F. Development of self-aeration process for supercritical chute flows [J]. International Journal of Multiphase Flow, 2016, 37: 172–180.CrossRefGoogle Scholar
  21. [21]
    Bai R., Zhang F., Liu S. et al. Air concentration and bubble characteristics sownstream of a chute aerator [J]. International Journal of Multiphase Flow, 2016, 87: 156–166.CrossRefGoogle Scholar
  22. [22]
    Bai R., Liu S., Wang W. et al. Experimental investigations on air-water flow properties of offset-aerator [J]. Journal of Hydraulic Engineering, ASCE, 2018, 144(2): 04017059.CrossRefGoogle Scholar
  23. [23]
    Zhang F. X. Mechanisms and calculating methods of self-aerated flow in open channels [D]. Doctoral Thesis, Chengdu, China: University of Sichuan, 2007(in Chinese).Google Scholar

Copyright information

© China Ship Scientific Research Center 2018

Authors and Affiliations

  • Rui-di Bai (白瑞迪)
    • 1
  • Fa-xing Zhang (张法星)
    • 1
  • Wei Wang (王韦)
    • 1
  • Shanjun Liu (刘善均)
    • 1
  1. 1.State Key Laboratory of Hydraulics and Mountain River EngineeringSichuan UniversityChengduChina

Personalised recommendations