Numerical Simulation of Cavitation and Aeration in Discharge Gated Tunnel of a Dam Based on the VOF Method

Abstract:

Cavitation, usually known as a destructive phenomenon, involves turbulent unsteady two-phase flow. Having such features, cavitating flows have been turned to a challenging topic in numerical studies and many researches are being done for better understanding of bubbly flows and proposing solutions to reduce its consequent destructive effects. Aeration may be regarded as an effective protection against cavitation erosion in many hydraulic structures, like gated tunnels. The paper concerns numerical simulation of flow in discharge gated tunnel of a dam using RNG model coupled with the volume of fluid (VOF) method and the zone which is susceptible of cavitation inception in the tunnel is predicted. Then a vent is considered in the mentioned zone for aeration and the numerical simulation is done again to study the effects of aeration. The results show that aeration is an impressively useful method to exclude cavitation in mentioned tunnels.

• Periodical: Applied Mechanics and Materials (Volumes 110-116)
• Pages: 2754-2761
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.110-116.2754
• Online since: October 2011
• Authors: Razieh Jalalabadi, Norouz Mohammad Nouri
• Keywords: Aeration, Cavitation, Turbulent Flow, Two-Phase Flow, Volume of Fluid (VOF) Method

References

[1] Y. Xiong, Y. Gao, W. An, Comparison of Turbulence Models in Predicting Unsteady Supercavitating Flow, Sixth International Symposium on Cavitation, CAV2006, Netherlands, Sep. (2006).

[2] F. R. Young, Cavitation, 1st ed, Imperial College press, (1999).

[3] C.W. Hirt, B.D. Nichols., Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries, Journal of Computational Physics, vol. 39, pp.201-225, Jan. (1981).

DOI: 10.1016/0021-9991(81)90145-5

[4] M. R. Najafi, A. R. Zarrati, Numerical simulation of air–water flow in gated tunnels, Proceedings of the ICE - Water Management, vol 163, Issue 6, p.289 –295, June. (2010).

DOI: 10.1680/wama.2010.163.6.289

[5] G. E. Reisman, M. E. Duttweiler, and C. E. Brennen, Effect of Air Injection on the Cloud Cavitation of a Hydrofoil", ASME Fluids Engineering Division Summer Meeting, FEDSM, 97, June, (1997).

[6] H. R., Jahed Motlagh, M. R. Noban, M. A. Eshraghi, Ansys, 1st Ed, IUST Press, Tehran, pp.285-297, (2002).

[7] X. Wang, J. An, X. Wang, Z. Zhang, C. Wang, Q. Duan, Numerical Simulation of Long-Distance Diversion Tunnel with Free Flow Based on the VOF Method", Proceedings of International Symposium on Information Science and Engineering, ISISE , 08, vol. 1, pp.19-23, Dec. (2008).

DOI: 10.1109/isise.2008.240

[8] S.V. Patankar, D.B. Spalding, A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows, International Journal of Heat and Mass Transfer, vol. 15, Issue 10, pp.1787-1806, Oct. (1972).

DOI: 10.1016/0017-9310(72)90054-3

[9] Yakhot, S.A. Orszag, Renormalization-Group Analysis of Turbulence, Journal of Scientific Computing, vol 1, no. 1, pp.3-51, Dec. (1986).

[10] A., Mohaghegh, J. H. WU, Effects of hydraulic and geometric parameters on downstream cavity length of discharge tunnel service gate, Journal of Hydrodynamics, vol. 21, Issue 6, pp.774-778, Dec. (2009).

DOI: 10.1016/s1001-6058(08)60212-7