Skip to main content
SpringerLink
Log in

A numerical model for air concentration distribution in self-aerated open channel flows

  • Published:
Journal of Hydrodynamics Aims and scope Submit manuscript

Abstract

The self-aeration in open channel flows, called white waters, is a phenomenon seen in spillways and steep chutes. The air distribution in the flow is always an important and fundamental issue. The present study develops a numerical model to predict the air concentration distribution in self-aerated open channel flows, by taking the air-water flow as consisting of a low flow region and an upper flow region. On the interface between the two regions, the air concentration is 0.5. In the low flow region where air concentration is lower than 0.5, air bubbles diffuse in the water flow by turbulent transport fluctuations, and in the upper region where air concentration is higher than 0.5, water droplets and free surface roughness diffuse in the air. The air concentration distributions obtained from the diffusion model are in good agreement with measured data both in the uniform equilibrium region and in the self-aerated developing region. It is demonstrated that the numerical model provides a reasonable description of the self-aeration region in open channel flows.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. MATOS J., FRIZELL K. M. Air concentration and ve locity measurements on self-aerated flow down stepped chutes[C]. Conference on Water Resource Enginee ring and Water Resources Planning and Management. Minneapolis, USA, 2000, 1–10.

    Google Scholar 

  2. PFISTER M., LUCAS J. and HAGER W. H. Chute aerators: Pre aerated approach flow[J]. Journal of Hydraulic Engineering, ASCE, 2011, 137(11): 1452–1461.

    Article  Google Scholar 

  3. 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.

    Article  Google Scholar 

  4. CHANSON H. Compressibility of extra-high-velocity aerated flow: A discussion[J]. Journal of Hydraulic Research, 2004, 42(2): 213–215.

    Article  Google Scholar 

  5. 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.

    Article  Google Scholar 

  6. PFISTER M., HAGER W. H. Self-entrainment of air on the stepped spillways[J]. International Journal of Multiphase Flow, 2011, 37(2): 99–107.

    Article  Google Scholar 

  7. WILHELMS S. C., GULLIVER J. S. Bubbles and waves description of self-aerated spillway flow[J]. Journal of Hydraulic Research, 2005, 43(5): 522–531.

    Article  Google Scholar 

  8. TOOMBES L., CHANSON H. Air-water mass transfer on a stepped waterway[J]. Journal of Environmental Engineering, 2005, 131(10): 1377–1386.

    Article  Google Scholar 

  9. KRAMER K., HAGER W. H. Air transport in chute flows[J]. International Journal of Multiphase Flow, 2005, 31(10): 1181–1197.

    Article  Google Scholar 

  10. ARAS E., BERKUN M. Effects of tail water depth on spillway aeration[J]. Water Statistika of Afrika, 2012, 38(2): 307–312.

    Google Scholar 

  11. CHANSON H., LUBIN P. Verification and validation of computational fluid dynamics (CFD) model for air entrainment at spillway aerators[J]. Canada Journal of Civil Engineering, 2010, 37(1): 135–138.

    Article  Google Scholar 

  12. CHANSON H. Bubble entrainment, spray and splashing at hydraulic jumps[J]. Journal of Zhejiang University SCIENCE A. 2006, 7(8): 1396–1405.

    Article  Google Scholar 

  13. GIRGIDOV A. D. Self-aeration of open channel flow[J]. Power Technology and Engineering, 2012, 45(5): 351–355.

    Google Scholar 

  14. DENG Jun, XU Wei-lin and QU Jing-xue et al. Measurement and calculation of air concentration distribution of self-aerated flow in spillway tunnel[J]. Journal of Hydraulic Engineering, 2002, (4): 23–36(in Chinese).

    Google Scholar 

  15. SABBAGH-YAZDI S. R., REZAEI-MANIZANI H. and MASTORAKIS N. E. Effects of bottom aerator and self-aeration in steep chute spillway on cell center finite volume solution of depth-averaged flow[J]. International Journal of Mathematical Models and Methods in Applied Sciences, 2008, 2(2): 154–161.

    Google Scholar 

  16. VIDAL L. E. O., RODRIGUEZ O. M. H. and ESTEVAM V. et al. Experimental investigation of gravitational gas separation in an inclined annular channel[J]. Experimental Thermal and Fluid Science, 2012, 39: 17–25.

    Article  Google Scholar 

  17. STEVEN C., GULLIVER J. S. Bubbles and waves de-scription of self-aerated spillway flow[J]. Journal of Hydraulic Research, 2008, 46(3): 420–423.

    Article  Google Scholar 

  18. WILHELMS S. C. Gas transfer, cavitation, and bulking in self-aerated spillway flow[J]. Journal of Hydraulic Research, 2005, 45(4): 532–539.

    Article  Google Scholar 

  19. CHANSON H. Hydraulics of aerated flows: qui pro quo?[J]. Journal of Hydraulic Research, 2013, 51(3): 223–243.

    Article  Google Scholar 

  20. ZHANG Fa-xing, XU Wei-lin and ZHU Ya-qin. 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 

  21. SIMĐES A. L. A., SCHULZ H. E. and PORTO R. M. et al. Free-surface profiles and turbulence characteristics in skimming flows along stepped chutes[J]. Journal of Water Resource and Hydraulic Engineering, 2013, 2(1): 1–12.

    Google Scholar 

  22. 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.

    Article  Google Scholar 

  23. PFISTER Michael, CHANSON Hubert. Two-phase air-water flows: Scale effects in physical modeling[J]. Journal of Hydrodynamics, 2014, 26(2): 291–298.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 650061, China

    Wang-ru Wei  (卫望汝), Jun Deng  (邓军), Fa-xing Zhang  (张法星) & Zhong Tian  (田忠)

Authors
  1. Wang-ru Wei  (卫望汝)
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jun Deng  (邓军)
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Fa-xing Zhang  (张法星)
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Zhong Tian  (田忠)
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Jun Deng  (邓军).

Additional information

Project supported by the National Natural Science Foundation of China (Grant No. 51179113), the Doctoral Program of China Education Ministry (Grant No. 20120181110083).

Biography: WEI Wang-ru (1988-), Male, Ph. D.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wei, Wr., Deng, J., Zhang, Fx. et al. A numerical model for air concentration distribution in self-aerated open channel flows. J Hydrodyn 27, 394–402 (2015). https://doi.org/10.1016/S1001-6058(15)60497-8

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1016/S1001-6058(15)60497-8

Key words

Search

Navigation