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Near-Field Hydrodynamic Analysis of the Submerged Thermal Discharge Using CFD Model

CFD 모델을 이용한 수중방류 온배수의 근역 동수역학 해석

  • Hwang, In-Tae (Environmental Technology Department, KEPCO Engineering & Construction company Inc.) ;
  • Kim, Deok-Ho (Environmental Technology Department, KEPCO Engineering & Construction company Inc.)
  • 황인태 (한국전력기술(주) 환경기술그룹) ;
  • 김덕호 (한국전력기술(주) 환경기술그룹)
  • Received : 2011.10.06
  • Accepted : 2011.12.02
  • Published : 2011.12.30

Abstract

The buoyancy and initial momentum fluxes make near-field dominated by buoyant jet when thermal discharge releases underwater. In order to estimate prediction capabilities of those near-field phenomena, non-hydrostatic RANS applied CFD(Computational Fluid Dynamic) model was used. Condition of model was composed based on past laboratory experiments. Numerical simulations carried out for the horizontal buoyant jet in the stagnant flow and vertical buoyant jet into crossflow. The results of simulation are compared with the terms of trajectory and dilution rate of laboratory experiments and analytic model(CorJET) results. CFD model showed a good agreement with them. CFD model can be appropriate for assessment of submerged thermal discharge effect because CFD model can resolve the limitations of near-field analytic model and far-field quasi 3D hydrodynamic model. The accuracy and capability of the CFD model is reviewed in this study. If the computational efficiency get improved, CFD model can be widely applied for simulation of transport and diffusion of submerged thermal discharge.

온배수의 수중 방류 시 강한 방류 모멘텀 플럭스와 부력 플럭스에 의해 수중제트 인근에는 부력제트가 지배적인 근역이 형성되며, 이러한 근역을 해석하는 도구로써 비정수압 RANS 방정식을 적용한 전산유체역학(CFD) 모델을 이용하여 근역에 대한 적용성을 검토해 보았다. 과거 연구된 바 있는 원형 부력제트 수리실험과 유사한 조건으로 모델을 구성하고 정류시의 수평 부력 제트 경우와 가로흐름시 수직 부력 제트 경우에 대해 수치 실험을 수행하였다. CFD 수치실험의 결과는 수리실험 및 해석해 모델(CorJET)의 결과와 무차원화한 중심 궤적 및 희석율에 대해 비교 검증하였는데, 실제 수리실험의 결과와 잘 일치하는 것으로 나타났다. CFD 모델은 현재 근역 해석해 모델과 광역 준3차원 해수유동 모델이 가지고 있는 한계를 모두 보완할 수 있어 수중방류 온배수 영향해석에 적합한 모델이며, 본 연구를 통해 근역해석의 적합성을 확인하였으므로 향후 계산효율이 확보된다면 수중방류 온배수의 이동 및 확산 해석 도구로써 널리 활용될 것으로 기대된다.

Keywords

References

  1. 서승원 (1998). 근역에서 부력 입자 추적 모형을 적용한 Eulerian-Lagrangian 결합에 의한 온수확산, 한국해안.해양공학회지, 10(2), 73-82.
  2. 이남주, 최흥식, 허재영 (1995). 가로흐름 수역으로 방출되는 3차원 온배수 난류모형, 한국해안.해양공학회지, 7(2), pp. 148-155.
  3. Adams, E.E. and Cosler, D.J. (1987). Predicting Circulation and Dispersion Near Coastal Power Plants: Applications Using Models TEA and ELA, Energy Laboratory Report No. MIT-EL 87-008, Massachusetts Institute of Technology, Cambridge, Massachusetts.
  4. Anwar, H.O. (1972). Measurements on horizontal buoyant jets in calm ambient fluid, La Houille Blanche 27 (4).
  5. Bleninger, T. (2006). Coupled 3D hydrodynamic models for submarine outfalls. Denvironmental hydraulic design and control of multiport diffusers, ph.D. Thesis, Institute for Hydromechanics, University Karlsruhe.
  6. Cedervall, K. (1963). The Initial Mixing of Jet Disposal into a Recipient, Tech. Reports 14 and 15, Div. of Hydraulics, Chalmers Institute of Technology, Goteborg, Sweden.
  7. Cheung, V. (1991). Mixing a Round Buoyant Jet in a Current, Ph.D. Thesis, University of Hong Kong, Hong Kong
  8. Davidson, M.J. and Pun, K.L. (1999). Weakly advected jets in crossow, J. Hydr. Engrg., ASCE 125, 47-58. https://doi.org/10.1061/(ASCE)0733-9429(1999)125:1(47)
  9. Fan, L.N. (1967). Turbulent Buoyant Jets into Stratied or Flowing Ambient Fluids. Report No.KH-R-15, W.M. Keck Laboratory of Hydrology and Water Resources, California Institute of Technology, Pasadena, CA.
  10. Hansen, J. and Schroder, H. (1968). Horizontal Jet Dilution Studies by Use of Radiocactive Isotopes, Acta Polytechnica Scandinavia, Civil Engineering and Building Construction Series No. 49, Copenhagen
  11. Hirt, C.W. (1994). Weir discharge and counter currents. Proceedings 1st International Conference on Hydroinformatics. Delft. 19-23 September
  12. Hirt, C.W., Nichols, B.D., (1981). Volume of fluid (VOF) method for the dynamics of free boundaries. J. Comp. Physics 39, 201-225. https://doi.org/10.1016/0021-9991(81)90145-5
  13. Hirt, C.W., Sicilian, J.M., (1985). A porosity technique for the definition of obstacles in rectangular cell meshes. Proc. Fourth International Conf. Ship Hydro. National Academy of Science, Washington, DC.
  14. Jirka, G.H. (2004). Integral Model for Turbulent Buoyant Jets in Unbounded Stratified Flows. Part I: Single Round Jet. Environmental Fluid Mechanics 4, 1-56. https://doi.org/10.1023/A:1025583110842
  15. Kim, D.G., Seo, I.W. (2004). Numerical simulation of the buoyant flow of heated water discharged from submerged side outfalls in shallow and deep water, KSCE J. of civil eng., 8(2), 255-263. https://doi.org/10.1007/BF02829126
  16. Kim, Y.D., Seo, I.W., Kang, S.W. and Oh B.C. (2002). Jet integralparticle tracking hybrid model for single buoyant jets, J. of Hydr. Engrg., ASCE, 125(8), 753-760.
  17. Liseth, P. (1970). Mixing of merging Buoyant jets from a manifold in stagnant receiving water of uniform density. Univ. Calif., Berkeley, Hydraul. Eng. Lab. Tech. Rep. HEL 23-1.
  18. Nichols, B.D., Hirt, C.W., Hotchkiss, R.S., (1980). SOLAVOF: A Solution Algorithm for Transient Fluid Flow with Multiple Free Boundaries, LA8355. Los Alamos National Laboratory.
  19. Tsubono T., Nakashiki N., Maruyama Y. (1998). Diffusion Behavior of Buoyant Jets Discharged from a Multi-Pipe outlet. Experimental Elucidation of the Diffusion Pheomena and Applicability of a three Dimensional Numerical Simulation to the Phenomena, Abiko Research Laboratory Report, No.U97057.
  20. Wendt, J.F. (2009). Computational Fluid dynamics : an introduction (3rd ED.), Springer-Verlag, Berlin, Heidelberg.
  21. Wright, S.J. (1977). Mean behavior of buoyant jets in a crossow, J. Hydraul. Div., ASCE 103(HY5), 499-513(5), 643-656.
  22. Zhang, X.Y. (1995). Ocean outfall modeling: Interfacing near and far field models with particle tracking method, ph.D. Thesis, MIT.
  23. Zhang, X.Y. and Adams, E.E. (1999). Prediction of near field plume characteristics using far field circulation model, J. of Hydr. Engrg., ASCE, 125(3), 233-241. https://doi.org/10.1061/(ASCE)0733-9429(1999)125:3(233)
  24. Ziji, F. (2002). On the effect of non-hydrostatic simulation on buoyant jets. MSc-report, Delft University of Technology.

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