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Shallow-water analysis of gravity-current flows past isolated obstacles

Published online by Cambridge University Press:  10 September 2009

E. GONZALEZ-JUEZ
Affiliation:
Department of Mechanical Engineering, University of California at Santa Barbara, Santa Barbara, CA, USA
E. MEIBURG*
Affiliation:
Department of Mechanical Engineering, University of California at Santa Barbara, Santa Barbara, CA, USA
*
Email address for correspondence: meiburg@engineering.ucsb.edu

Abstract

The flow of a partial-depth lock-exchange gravity current past an isolated bottom-mounted obstacle is studied by means of two-dimensional direct numerical simulations and steady shallow-water theory. The simulations indicate that the flux of the current downstream of the obstacle is approximately constant in space and time. This information is employed to extend the shallow-water models of Rottman et al. (J. Hazard. Mater., vol. 11, 1985, pp. 325–340) and Lane-Serff, Beal & Hadfield (J. Fluid Mech., vol. 292, 1995, pp. 39–53), in order to predict the height and front speed of the downstream current as functions of the upstream Froude number and the ratio of obstacle to current height. The model predictions are found to agree closely with the simulation results. In addition, the shallow-water model provides an estimate for the maximum drag that lies within 10% of the simulation results for obstacles much larger than the boundary-layer thickness.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

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References

REFERENCES

Armi, L. & Farmer, D. M. 1986 Maximal two-layer exchange through a contraction with barotropic net flow. J. Fluid Mech. 164, 2751.CrossRefGoogle Scholar
Baines, P. G. 1995 Topographic Effects in Stratified Flows. Cambridge University Press.Google Scholar
Benjamin, T. B. 1968 Gravity currents and related phenomena. J. Fluid Mech. 31, 209248.CrossRefGoogle Scholar
Birman, V. K., Battandier, B. A., Meiburg, E. & Linden, P. F. 2007 Lock-exchange flows in sloping channels. J. Fluid Mech. 577, 5377.Google Scholar
Birman, V. K., Martin, J. E. & Meiburg, E. 2005 The non-Boussinesq lock-exchange problem. Part 2. High-resolution simulations. J. Fluid Mech. 537, 125144.CrossRefGoogle Scholar
Braucher, E. P. 1950 Initial characteristics of density current flow. Master's thesis, MIT, Cambridge, MA.Google Scholar
Breuer, M., Bernsdorf, J., Zeiser, T. & Durst, F. 2000 Accurate computations of the laminar flow past a square cylinder based on two different methods: lattice-Boltzmann and finite-volume. Intl J. Heat Fluid Flow 21 (2), 186196.Google Scholar
Britter, R. E. & Linden, P. F. 1980 The motion of the front of a gravity current travelling down an incline. J. Fluid Mech. 99, 531543.CrossRefGoogle Scholar
Cantero, M. I., Balachandar, S., Garcia, M. H. & Bock, D. 2008 Turbulent structures in planar gravity currents and their influence on the flow dynamics. J. Geophys. Res. 113, C08018, doi:10.1029/2007JC004645.Google Scholar
Cantero, M. I., Lee, J. R., Balachandar, S. & Garcia, M. H. 2007 On the front velocity of gravity currents. J. Fluid Mech. 586, 139.CrossRefGoogle Scholar
Chang, K. S., Constantinescu, G. & Park, S-O. 2006 Analysis of the flow and mass transfer processes for the incompressible flow past an open cavity with a laminar and a fully turbulent incoming boundary layer. J. Fluid Mech. 561, 113145.CrossRefGoogle Scholar
Chang, K. S., Constantinescu, G. & Park, S-O. 2007 a The purging of a neutrally buoyant or a dense miscible contaminant from a rectangular cavity. Part 1. The case of an incoming laminar boundary layer. J. Hydraul. Engng 133, 361372.CrossRefGoogle Scholar
Chang, K. S., Constantinescu, G. & Park, S-O. 2007 b The purging of a neutrally buoyant or a dense miscible contaminant from a rectangular cavity. Part 2. The case of an incoming fully turbulent overflow. J. Hydraul. Engng 133, 373385.Google Scholar
Didden, N. & Maxworthy, T. 1982 The viscous spreading of plane and axisymmetric gravity currents. J. Fluid Mech. 121, 2742.Google Scholar
Ermanyuk, E. V. & Gavrilov, N. V. 2005 a Interaction of an internal gravity current with a submerged circular cylinder. J. Appl. Mech. Tech. Phys. 46 (2), 216223.Google Scholar
Ermanyuk, E. V. & Gavrilov, N. V. 2005 b Interaction of an internal gravity current with an obstacle on the channel bottom. J. Appl. Mech. Tech. Phys. 46 (4), 489495.Google Scholar
Ermanyuk, E. V. & Gavrilov, N. V. 2007 A note on the propagation speed of a weakly dissipative gravity current. J. Fluid Mech. 574, 393403.CrossRefGoogle Scholar
Farmer, D. M. & Armi, L. 1986 Maximal two-layer exchange over a sill and through the combination of a sill and contraction with barotropic flow. J. Fluid Mech. 164, 5376.Google Scholar
Gonzalez-Juez, E. D., Constantinescu, S. G. & Meiburg, E. 2007 A study of the interaction of a gravity current with a square cylinder using two-dimensional numerical simulations. In Proceedings of the 26th International Conference on Offshore Mechanics and Arctic Engineering, San Diego, CA.Google Scholar
Gonzalez-Juez, E. D., Meiburg, E. & Constantinescu, S. G. 2008 Gravity currents impinging on submerged cylinders: flow fields and associated forces. J. Fluid Mech. 631, 65102.Google Scholar
Gonzalez-Juez, E. D., Meiburg, E. & Constantinescu, S. G. 2009 a The interaction of a gravity current with a circular cylinder mounted above a wall: effect of the gap size. J. Fluid Struct. Accepted.Google Scholar
Gonzalez-Juez, E. D., Meiburg, E. Tokyay, T. & Constantinescu, S. G. 2009 b Gravity current flow past a circular cylinder: forces and wall shear stresses. J. Fluid Mech. Submitted.Google Scholar
Greenspan, H. P. & Young, R. E. 1978 Flow over a containment dyke. J. Fluid Mech. 87, 179.Google Scholar
Härtel, C., Meiburg, E. & Necker, F. 2000 Analysis and direct numerical simulation of the flow at a gravity-current head. Part 1. Flow topology and front speed for slip and no-slip boundaries. J. Fluid Mech. 418, 189212.CrossRefGoogle Scholar
Hogg, A. J., Hallworth, M. A. & Huppert, H. E. 2005 On gravity currents driven by constant fluxes of saline and particle-laden fluid in the presence of a uniform flow. J. Fluid Mech. 539, 349385.Google Scholar
Hopfinger, E. J. 1983 Snow avalanche motion and related phenomena. Annu. Rev. Fluid Mech. 15, 4776.Google Scholar
Huppert, H. & Simpson, J. 1980 The slumping of gravity currents. J. Fluid Mech. 99, 785799.Google Scholar
Keulegan, G. H. 1958 The motion of saline fronts in still water. Report 5831. National Bureau of Standards.Google Scholar
Kneller, B., Bennett, S. J. & McCaffrey, W. D. 1999 Velocity structure, turbulence and fluid stresses in experimental gravity currents. J. Geophys. Res. 104 (C3), 53815391.Google Scholar
Lane-Serff, G. F., Beal, L. M. & Hadfield, T. D. 1995 Gravity current flow over obstacles. J. Fluid Mech. 292, 3953.CrossRefGoogle Scholar
Lowe, R. J., Rottman, J. W. & Linden, P. F. 2005 The non-Boussinesq lock-exchange problem. Part 1. Theory and experiments. J. Fluid Mech. 537, 101124.Google Scholar
Oehy, C. D. & Schleiss, A. J. 2007 Control of turbidity currents in reservoirs by solid and permeable obstacles. J. Hydraul. Engng 133, 637648.Google Scholar
Ooi, S. K., Constantinescu, S. G. & Weber, L. 2005 Two-dimensional large eddy simulation of lock-exchange gravity current flows. In Proceedings of the 31st International Association Hydraulic Research Congress, Seoul, Korea.Google Scholar
Ooi, S. K., Constantinescu, S. G. & Weber, L. 2007 a A numerical study of intrusive compositional gravity currents. Phys. Fluids 19, 076602, doi:10.1063/1.2750672.Google Scholar
Ooi, S. K., Constantinescu, S. G. & Weber, L. 2007 b Numerical simulations of lock-exchange compositional gravity currents. J. Fluid Mech. Submitted.Google Scholar
Ooi, S. K., Constantinescu, S. G. & Weber, L. 2007 c Two-dimensional large-eddy simulation of lock-exchange gravity current flows at high Grashof numbers. J. Hydraul. Engng 133 (9), 10371047.Google Scholar
Pierce, C. D. 2001 Progress-variable approach for large eddy simulation of turbulent combustion. PhD thesis, Stanford University, Palo Alto, CA.Google Scholar
Pierce, C. D. & Moin, P. 2004 Progress-variable approach for large-eddy simulation of non-premixed turbulent combustion. J. Fluid Mech. 504, 7397.Google Scholar
Rottman, J. W. & Simpson, J. E. 1983 Gravity currents produced by instantaneous releases of a heavy fluid in a rectangular channel. J. Fluid Mech. 135, 95110.Google Scholar
Rottman, J. W., Simpson, J. E., Hunt, J. C. R. & Britter, R. E. 1985 Unsteady gravity current flows over obstacles: some observations and analysis related to the phase II trials. J. Hazard. Mater. 11, 325340.CrossRefGoogle Scholar
Shin, J. O., Dalziel, S. B. & Linden, P. F. 2004 Gravity currents produced by lock exchange. J. Fluid Mech. 521, 134.Google Scholar
Simpson, J. E. 1997 Gravity Currents in the Environment and the Laboratory. Cambridge University Press.Google Scholar
Turki, S., Abbassi, H. & Nasrallah, S. B. 2003 Effect of the blockage ratio on the flow in a channel with a built-in square cylinder. Comput. Mech. 33 (1), 2229.Google Scholar
Turner, J. S. 1973 Buoyancy Effects in Fluids. Cambridge University Press.Google Scholar
Wood, I. R. 1966 Studies in unsteady self preserving turbulent flows. Rep. No. 81. Water Research Laboratory, University of New South Wales.Google Scholar
Woods, A. W., Bursik, M. I. & Kurbatov, A. V. 1998 The interaction of ash flows with ridges. Bull. Volcanol. 60 (1), 3851.Google Scholar