Skip to main content
SpringerLink
Log in

Numerical simulations of intrusive gravity currents interacting with a bottom-mounted obstacle in a continuously stratified ambient

  • Original Article
  • Published:
Environmental Fluid Mechanics Aims and scope Submit manuscript

Abstract

In this study, the flow dynamics of intrusive gravity currents past a bottom-mounted obstacle were investigated using highly resolved numerical simulations. The propagation dynamics of a classic intrusive gravity current was first simulated in order to validate the numerical model with previous laboratory experiments. A bottom-mounted obstacle with a varying non-dimensional height of \(\tilde{D}=D/H\), where D is the obstacle height and H is the total flow depth, was then added to the problem in order to study the downstream flow pattern of the intrusive gravity current. For short obstacles, the intrusion re-established itself downstream without much distortion. However, for tall obstacles, the downstream flow was found to be a joint effect of horizontal advection, overshoot-springback phenomenon, and associated Kelvin-Helmholtz instabilities. Analysis of the numerical results show that the relationship between the downstream propagation speed and the obstacle height can be subdivided into three regimes: (1) a retarding regime (\(\tilde{D}\) \(\approx \) 0–0.3) where a 30 % increase in obstacle height leads to a 20 % reduction in propagation speed, simply due to the obstacle’s retarding effect; (2) an impounding regime (\(\tilde{D}\) \(\approx \) 0.3–0.6) where the additional 30 % increase in obstacle height only leads to a further (negligible) 5 % reduction in propagation speed, due to the accelerating effect of upstream impoundment and downstream enhanced mixing; and (3) a choking regime (\(\tilde{D}\) \(\approx \) 0.6–1.0) where the propagation speed is dramatically reduced due to the dominance of the obstacle’s blocking effect. The obstacle thickness was found to be irrelevant in determining the downstream propagation speed at least for the parameter range explored in this study. The present work highlights the significance of topographic effects in stratified flows with horizontal pressure forcing.

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

  1. An S, Julien PY (2014) Three-dimensional modelling of turbid density currents in Imha Reservoir, South Korea. J Hydraul Eng 140:495–513

    Article  Google Scholar 

  2. An S, Julien PY, Venayagamoorthy SK (2012) Numerical simulation of particle-driven gravity currents. Environ Fluid Mech 12:495–513

    Article  Google Scholar 

  3. Armi L (1986) The hydraulics of two flowing layers with different densities. J Fluid Mech 163:27–58

    Article  Google Scholar 

  4. Baines PG (1995) Topographic effects in stratified flows. Cambridge University Press, Cambridge

    Google Scholar 

  5. Benjamin TB (1968) Gravity currents and related phenomena. J Fluid Mech 31:05014004

    Article  Google Scholar 

  6. Birman VK, Battandier BA, Meiburg E, Linden PF (2007) Lock-exchange flows in sloping channels. J Fluid Mech 577:53–77

  7. Bolster D, Hang A, Linden PF (2008) The front speed of intrusions into a continuously stratified medium. J Fluid Mech 594:369–377

    Article  Google Scholar 

  8. Gonzalez-Juez E, Meiburg E (2009) Shallow-water analysis of gravity-current flow past isolated obstacles. J Fluid Mech 635:415–438

    Article  Google Scholar 

  9. Gonzalez-Juez E, Meiburg E, Constantinescu G (2009) Gravity currents impinging on submerged cylinders: flow fields and associated forces. J Fluid Mech 631:65–102

    Article  Google Scholar 

  10. Gonzalez-Juez E, Meiburg E, Tokyay T, Constantinescu G (2010) Gravity current flow past a circular cylinder: forces and wall shear stresses and implications for scour. J Fluid Mech 649:69–102

    Article  Google Scholar 

  11. Heimsund S (2007) Numerical simulation of turbidity currents: a new perspective for small- and large-scale sedimentological experiments. Master thesis in Department of Earth Science, University of Bergen

  12. Hirt CW (1993) Volume-fraction techniques: powerful tools for wind engineering. J Wind Eng Ind Aerodyn 46&47:327–338

    Article  Google Scholar 

  13. Hirt CW, Nichols BD (1981) Volume of fluid (VOF) method for the dynamics of free boundaries. J Comput Phys 39:1–11

    Article  Google Scholar 

  14. Klemp JB, Rotunno R, Skamarock WC (1994) On the dynamics of gravity currents in a channel. J Fluid Mech 269:169–198

    Article  Google Scholar 

  15. Lane-Serff GF, Beal LM, Hadfield TD (1995) Gravity current flow over obstacles. J Fluid Mech 292:39–53

    Article  Google Scholar 

  16. La Rocca M, Prestininzi P, Adduce C, Sciortino G, Hinkelmann R (2013) Lattice Boltzmann simulation of 3D gravity currents around obstacles. Int J Offshore and Polar Eng 23(3):178–185

    Google Scholar 

  17. Lombardi V, Adduce C, Sciortino G, La Rocca M (2015) Gravity currents flowing upslope: laboratory experiments and shallow-water simulations. Phys Fluids 27:016602

    Article  Google Scholar 

  18. Maxworthy T, Leilich J, Simpson JE, Meiburg EH (2002) The propagation of a gravity current into a linearly stratified fluid. J Fluid Mech 453:371–394

    Article  Google Scholar 

  19. Munroe JR, Voegeli C, Sutherland BR, Birman V, Meiburg EH (2009) Intrusive gravity currents from finite-length locks in a uniformly stratified fluid. J Fluid Mech 635:245–273

    Article  Google Scholar 

  20. Nasr-Azadani MM, Meiburg E (2014a) Turbidity currents interacting with three-dimensional seafloor topography. J Fluid Mech 745:409–443

    Article  Google Scholar 

  21. Nasr-Azadani MM, Meiburg E (2014b) Influence of seafloor topography on the depositional behavior of bi-disperse turbidity currents: a three-dimensional, depth-resolved numerical investigation. Environ Fluid Mech 14:319–342

    Article  Google Scholar 

  22. Nogueira HIS, Adduce C, Alves E, Franca MJ (2014) Dynamics of the head of gravity currents. Environ Fluid Mech 14:519–540

    Article  Google Scholar 

  23. Ozgokmen TM, Fischer PF, Johns WE (2006) Product water mass formation by turbulent density currents from a high-order nonhydrostatic spectral element model. Ocean Model 12:237–267

    Article  Google Scholar 

  24. Ozgokmen TM, Iliescu T, Fischer PF, Srinivasan A, Duan J (2007) Large eddy simulation of stratified mixing in two-dimensional dam-break problem in a rectangular enclosed domain. Ocean Model 16:106–140

    Article  Google Scholar 

  25. Ozgokmen TM, Fischer PF (2008) On the role of bottom roughness in overflows. Ocean Model 20:336–361

    Article  Google Scholar 

  26. Pope SB (2000) Turbulent flows. Cambridge University Press, Cambridge

    Book  Google Scholar 

  27. Price DJ (2008) Modelling discontinuities and Kelvin-Helmholtz instabilities in SPH. J Comput Phys 227:10040–10057

    Article  Google Scholar 

  28. Shin JO, Dalziel SB, Linden PF (2004) Gravity currents produced by lock exchange. J Fluid Mech 521:1–34

    Article  Google Scholar 

  29. Simpson JE (1982) Gravity currents in the laboratory, atmosphere, and ocean. Ann Rev Fluid Mech 14:213–234

    Article  Google Scholar 

  30. Simpson JE, Britter RE (1979) The dynamics of the head of a gravity current advancing over a horizontal surface. J Fluid Mech 94:477–495

    Article  Google Scholar 

  31. Simpson JE (1997) Gravity currents: in the environment and laboratory, 2nd edn. Cambridge University Press, Cambridge

    Google Scholar 

  32. Smagorinsky J (1963) General circulation experiments with the primitive equations. Mon Weather Rev 91:99–164

    Article  Google Scholar 

  33. Sutherland BR, Nault JT (2007) Intrusive gravity currents propagating along thin and thick interfaces. J Fluid Mech 586:109–118

    Article  Google Scholar 

  34. Tokyay T, Constantinescu G (2015) The effects of a submerged non-erodible triangular obstacle on bottom propagating gravity currents. Phys Fluids 27:056601

    Article  Google Scholar 

  35. Tokyay T, Constantinescu G, Gonzalez-Juez E, Meiburg E (2011) Gravity currents propagating over periodic arrays of blunt obstacles: effect of the obstacle size. J Fluid Struct 27:798–806

    Article  Google Scholar 

  36. Tokyay T, Constantinescu G, Meiburg E (2011) Lock-exchange gravity currents with a high volume of release propagating over a periodic array of obstacles. J Fluid Mech 672:570–605

    Article  Google Scholar 

  37. Tokyay T, Constantinescu G, Meiburg E (2012) Tail structure and bed friction velocity distribution of gravity currents propagating over an array of obstacles. J Fluid Mech 694:252–291

    Article  Google Scholar 

  38. Ungarish M, Huppert HE (2002) On gravity currents propagating at the base of a stratified ambient. J Fluid Mech 458:283–301

    Article  Google Scholar 

Download references

Acknowledgments

The authors thank the two anonymous referees for their constructive comments and recommendations. SKV gratefully acknowledges the support of the Office of Naval Research under Grants N00014-12-1-0279 and N00014-12-1-0938 (Scientific officers: Dr. Terri Paluszkiewicz and Dr. Scott Harper). The support of the National Science Foundation under Grant OCE-1151838 is also gratefully acknowledged.

Author information

Authors and Affiliations

  1. Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO, 80523-1372, USA

    Jian Zhou & Subhas K. Venayagamoorthy

Authors
  1. Jian Zhou
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Subhas K. Venayagamoorthy
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Subhas K. Venayagamoorthy.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhou, J., Venayagamoorthy, S.K. Numerical simulations of intrusive gravity currents interacting with a bottom-mounted obstacle in a continuously stratified ambient. Environ Fluid Mech 17, 191–209 (2017). https://doi.org/10.1007/s10652-016-9454-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10652-016-9454-3

Keywords

Search

Navigation