Studying Wind Effect on the Hydrodynamic Behavior of Lock-Exchange Density Current

Document Type : Research Article

Authors

1 Department of Mechanical Engineering, University Of Zanjan, Zanjan, Iran

2 Mechanical engineering department, University of Zanjan

Abstract

In the present study, the two-dimensional lock-exchange turbidity current under the influence of wind flow is modeled using open-source software. To solve this, the large eddy simulation method has been used in order to observe turbulent phenomena more accurately. By developing the two-phase solver of the software so that the equations of the volume of fluid method are coupled with the scalar equation of concentration, the three-phase problem is simulated as a phase of a mixture of dense fluid and pure water next to the air phase. The results show that an increase in wind speed reduces the buoyancy force driving the turbidity current and increases the entrainment, which means faster pollution of water areas. This increase in wind speed also increases the wall shear stress, with the difference that the amount of wall shear stress at low wind speeds is not significant. So this prevents a significant change in the deposition behavior of the current. Studying the current's sedimentation behavior, showed that at high wind speeds, the co-current wind flow corresponding to the turbidity current has more harmful effects than the reverse wind flow and its sediment accumulation is getting higher.

Keywords

Main Subjects

References

[1] R.I. Wilson, H. Friedrich, C. Stevens, Turbulent entrainment in sediment-laden flows interacting with an obstacle, Physics of Fluids, 29(3) (2017) 036603.
[2] R. Manica, Sediment gravity flows: Study based on experimental simulations, Hydrodynamics-Natural Water Bodies, 1 (2012).
[3] A. Koohandaz, E. Khavasi, H. Yousefi, H. Sadeghi Sarsari, Air flow effect on the behavior of lock-exchange gravity current, Journal of Hydraulic Structures, 6(1) (2020) 33-54.
[4] F. Necker, C. Härtel, L. Kleiser, E. Meiburg, High-resolution simulations of particle-driven gravity currents, International Journal of Multiphase Flow, 28(2) (2002) 279-300.
[5] F. De Rooij, S. Dalziel, Time-resolved measurements of the deposition under turbidity currents, in:  Proceedings of the Conference on Sediment Transport and Deposition by Particulate Gravity Currents, Leeds, 1998.
[6] M. Nasr-Azadani, B. Hall, E. Meiburg, Polydisperse turbidity currents propagating over complex topography: comparison of experimental and depth-resolved simulation results, Computers & Geosciences, 53 (2013) 141-153.
[7] M. Nasr-Azadani, E. Meiburg, Turbidity currents interacting with three-dimensional seafloor topography, Journal of Fluid Mechanics, 745 (2014) 409.
[8] K. Bhaganagar, Role of head of turbulent 3-D density currents in mixing during slumping regime, Physics of Fluids, 29(2) (2017) 020703.
[9] S.a.K. Teymouri, Ehsan., Numerical study of lock exchange turbidity current depositional
behavior in stratified environment, Amirkabir Journal of Mechanical Engineering, 50(1-3) (2018).
[10] W. Ding, T. Wu, B. Qin, Y. Lin, H. Wang, Features and impacts of currents and waves on sediment resuspension in a large shallow lake in China, Environmental Science and Pollution Research, 25(36) (2018) 36341-36354.
[11] A. Gkesouli, A. Stamou, A CFD modeling procedure to assess the effect of wind in settling tanks, Journal of Hydroinformatics, 21(1) (2019) 123-135.
[12] L. Morales‐Marin, J. French, H. Burningham, R. Battarbee, Three‐dimensional hydrodynamic and sediment transport modeling to test the sediment focusing hypothesis in upland lakes, Limnology and Oceanography, 63(S1) (2018) S156-S176.
[13] X. Xie, M. Li, W. Ni, Roles of Wind‐Driven Currents and Surface Waves in Sediment Resuspension and Transport During a Tropical Storm, Journal of Geophysical Research: Oceans, 123(11) (2018) 8638-8654.
[14] P. Lopes, Free-surface flow interface and air-entrainment modelling using OpenFOAM, 2013.
[15] O. Ubbink, Numerical prediction of two fluid systems with sharp interfaces,  (1997).
[16] J.U. Brackbill, D.B. Kothe, C. Zemach, A continuum method for modeling surface tension, Journal of computational physics, 100(2) (1992) 335-354.
[17] S.K. Friedlander, Smoke, dust and haze: Fundamentals of aerosol behavior, wi,  (1977).
[18] W.C. Hinds, Aerosol technology: properties, behavior, and measurement of airborne particles, John Wiley & Sons, 1999.
[19] S.B. Pope, Turbulent flows, in, IOP Publishing, 2001.
[20] H. Tofighian, E. Amani, M. Saffar-Avval, A large eddy simulation study of cyclones: The effect of sub-models on efficiency and erosion prediction, Powder Technology, 360 (2020) 1237-1252.
[21] W.-W. Kim, S. Menon, A new dynamic one-equation subgrid-scale model for large eddy simulations, in:  33rd Aerospace Sciences Meeting and Exhibit, 1995, pp. 356.
[22] J. Pelmard, S. Norris, H. Friedrich, LES grid resolution requirements for the modelling of gravity currents, Computers & Fluids, 174 (2018) 256-270.
[23] L. Ottolenghi, C. Adduce, R. Inghilesi, V. Armenio, F. Roman, Entrainment and mixing in unsteady gravity currents, Journal of Hydraulic Research, 54(5) (2016) 541-557.
[24] R. Ouillon, E. Meiburg, B.R. Sutherland, Turbidity currents propagating down a slope into a stratified saline ambient fluid, Environmental Fluid Mechanics, 19(5) (2019) 1143-1166.
[25] Y. NiÑo, F. Lopez, M. Garcia, Threshold for particle entrainment into suspension, Sedimentology, 50(2) (2003) 247-263.
Amirkabir Journal of Mechanical Engineering
Volume 53, Issue 9
December 2021
Pages 4807-4826

Files

Share

How to cite

Statistics