Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
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Bidirectional Spreading of Gravity Underflows on an Incline

사면에 발달하는 하층밀도류의 이차원흐름

  • 최성욱 (연세대학교 사회환경·건축공학부)
  • Published : 1999.02.01
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Abstract

In continental margins, turbid underflows which are not confined to a given channel, are free to spread laterally as well as longitudinally. Lateral spreading can reduce substantially the run out distance of flows along continental shelves and slopes. Laboratory experiments with a large tank, employing saline density currents as surrogates for fine-grained turbidity flow, coupled with dimensional analysis, have been used to develop a simple expression for lateral spreading rates of two-dimensional flows on sloping beds. characteristic length and time are determined by the flow discharge and buoyancy flux at the inlet. By knowing the initial width of the flow, the spreading law can be used to estimate the maximum width of the current at different times as well as the longitudinal spreading rate. Predictions for flows compare favorably against observations.

대륙붕에서 부유사 하층밀도류는 양측이 수로에 제한을 받지 않기 때문에 주흐름방향인 종방향뿐만 아니라 횡방향으로도 자유롭게 흐른다. 횡방향흐름은 대륙붕 및 대륙붕사면을 따라 흐르는 밀도류의 종방향 도달거리를 크게 감축시킬 수 있다. 본 연구에서는 부유사 밀도류 대신에 염수를 이용한 밀도류 실험을 대형 탱크를 이용하여 실시하였고, 차원해석을 통하여 사면에서 밀도류의 흐름률에 관한 간단한 식을 개발하였다. 특성길이 및 특성시간은 유입부에서의 유량과 부력흐름률의 함수로 나타내었다. 유입부의 폭이 주어질 경우,개발된 흐름식을 사용하여 시간에 따른 밀도류의 최대폭과 종방향으로의 전파속도를 계산할 수 있다. 식에 의한 예측값과 관측값이 서로 잘 일치함을 보였다.

Keywords

References

  1. Journal of Hydraulic Engineering v.112 no.1 Behavior of density currents on an incline Alavian, V.
  2. The Polar Oceans and Their Role in Shaping the Global Environment Modelling of deep-sea gravity currents using an integrated plume model Alendal, G.;Drange, H.;Haugan, P. M.
  3. Journal of Hydraulic Research v.28 no.1 Weakly depositing turbidity current on a small slope Altinakar, S.;Graf, W. H.;Hopfinger, E. J.
  4. Proceedings of the Second International IAHR Symposium on Stratified Flows Three-dimensional underflows discharges Baddour, R. E.;Ferraro, V.;Chu, V. H.
  5. Journal of Fluid Mechanics v.31 Gravity currents and related phenomena Benjamin, T. B.
  6. Journal of Fluid Mechanics v.99 The motion of the front of gravity current travelling down an incline Britter, R. E.;Linden, P. F.
  7. Journal of Hydraulic Research v.29 no.2 Gravity currents advancing into a coflowing fluid Buhler, J.;Wright, S. J.;Kim, Y.
  8. Journal of Hydraulic Research v.30 no.5 Modeling of one-dimensional turbidity currents with a dissipative-Galerkin finite element method Choi, S.-U.;Garcia, M.
  9. Ph. D. thesis, University of Illinois Layer-averaged modeling of turbidity currents with a finite element method Choi, S.-U.
  10. Fourth International Symposium on Stratified Flows, Proceedings of the Conference Experiments on 3-d turbulent density currents Christodoulou, G. C.;Tzachou, F. E.
  11. Encyclopedia of Fluid Mechanics v.6 Surface buoyant jets and plumes Chu, V. H.;Jirka, G. H.;N. P. Cheremisinoff(ed.)
  12. Journal of The Hydraulics Division v.93 no.HY6 Three-dimensional density current Fietz, T. R.;Wood, I. R.
  13. Mixing in Inland and Coastal Waters Fischer, H. B.;List, E. J.;Koh, R. C. Y.;Imberger, J.;Brooks, N. H.
  14. Journal of Hydraulic Research v.22 Investigation of plunging density currents generated by inflows in lake Hauenstein, W.;Dracos, T. H.
  15. Journal of Geophysical Research v.88 no.c1 On the frontal speeds of internal gravity surges on sloping boundaries Hay, A.E.
  16. Journal on Fluid Mechanics v.99 The slumping of gravity currents Huppert, H.E.;Simpson, J.E.
  17. Journal of The Hydraulics Division v.103 no.HY5 Density currents and their applications Kao, T. W.
  18. Sedimentology v.23 Energy relations of density current flows: an experimental investigation Kersey, D.G.;Hsu, K.J.
  19. U.S. National Bureau of Standards Report, 5168 Thirteenth progress report on model laws for density currents. An experimental study of the motion of saline water from locks into fresh water channels Keulegan, G. H.
  20. Marine Geology v.40 Experiments on non-channelized turbidity currents and their deposits Luthi, S.
  21. Canadian Journal of Earth Sciences v.3 Experiments on density and turbidity currents. I. Motion of the head Middleton, G. V.
  22. Journal of Fluid Mechanics v.171 Self accelerating turbidity currents Parker, G.;Fukushima, Y.;Pantin, H. M.
  23. Journal of the Waterway Port Coasta and Ocean Division v.105 no.WW4 Mixing of buoyant surface jet over sloping bottom Safaie, B.
  24. Journal of the Engineering Mechanics Division v.94 no.EM6 Motion of two-dimensional starting plume Tsang, G.;Wood, I. R.
  25. Theoretical and experimental investigation of three-dimensional boundary-attached density currents Tsihrintzis, V. A.
  26. Geophysical Monograph 85 Modelling of deep-sea gravity currents using an integrated plume model Alendal, G.;Drange, H.;Haugan, P.M.