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Directional Wave Generation in the Navier-Stokes Equations Using the Internal Wave Maker

Navier-Stokes 방정식 모형의 경사지게 입사하는 파랑 내부조파

  • Ha, Tae-Min (Dept. of Civil and Envir. Engrg., Hanyang Univ.) ;
  • NamGung, Don (Dept. of Civil and Envir. Engrg., Hanyang Univ.) ;
  • Cho, Yong-Sik (Dept. of Civil and Envir. Engrg., Hanyang Univ.)
  • 하태민 (한양대학교 건설환경공학과 BK21 사업단) ;
  • 남궁돈 (한양대학교 대학원 건설환경공학과) ;
  • 조용식 (한양대학교 공과대학 건설환경공학과)
  • Received : 2012.02.12
  • Accepted : 2012.03.08
  • Published : 2012.06.30

Abstract

A numerical modeling has become increasingly popular and more important to the study of water waves with a rapid advancement of computer technology. However, different types of problems are induced during simulating wave motion. One of the key problems is re-reflection to a computation domain at the incident boundary. The internal wave generating-absorbing boundary conditions have been commonly used in numerical wave models to prevent re-reflection. For the Navier-Stokes equations model, the internal wave maker using a mass source function of the continuity equation has been used to generate various types of waves. Nonetheless, almost every numerical experiment is performed in two dimensions and only a few tests have been expanded to three dimensions. More recently, a momentum source function of the Boussinesq equations is applied to generate essentially directional waves in the three dimensional Navier-Stokes equations model. In this study, the internal wave maker using a momentum source function is employed to generate targeted linear waves in the three-dimensional LES model.

컴퓨터 기술의 발달과 더불어 수치해석을 이용한 파랑변형에 대한 연구는 꾸준히 발전하고 있으며 점점 중요한 역할을 수행하고 있다. 하지만 수치모형을 이용한 연구에는 다양한 문제점이 발생할 우려가 있는데, 그 중 가장 빈번하게 발생하는 문제 중의 하나가 파랑의 조파지점에서 발생하는 수치수조내로의 재반사 문제이다. 재반사를 막기 위한 방법으로는 내부조파 기법을 이용하는 것이 일반적이다. Navier-Stokes 방정식 모형에서는 질량 원천항을 이용한 내부조파 기법을 주로 사용해 왔으나, 기존의 연구는 대부분 연직 2차원 수치모형을 이용한 연구에 국한되어 있었다. 그러나 3차원 수치모형을 이용한 연구가 점차 활발해지면서 3차원 Navier-Stokes 방정식 모형의 내부조파 기법에 대한 필요성이 증대되고 있다. 최근 RANS(Reynolds averaged Navier-Stokes) 방정식 모형에서 Boussinesq 방정식의 운동량 원천항을 활용하여 파랑을 내부조파하는 기법이 발표되어 3차원 공간에서 경사지게 입사하는 파랑을 성공적으로 재현하였다. 본 연구에서는 LES(large eddy simulation) 기반의 3차원 Navier-Stokes 방정식 수치모형에 운동량 원천항을 이용한 내부조파 기법을 적용하여 목표파랑을 조파하고 해석해와 비교하여 이를 검증하였다.

Keywords

References

  1. 하태민, 김형준, 조용식 (2010). "내부조파기법을 활용한 Navier-Stokes 방정식 모형의 고립파 처오름 수치모의." 한국수자원학회논문집, 한국수자원학회, 제43권, 제9호, pp. 801-811.
  2. Choi, J.W., and Yoon, S.B. (2009). "Numerical simulation using momentum source wave-maker applied RANS equation model." Coastal Engineering, Vol. 56, No. 10, pp. 1043-1060. https://doi.org/10.1016/j.coastaleng.2009.06.009
  3. Deardorff, J.W. (1970). "A numerical study of threedimensional turbulent channel flow at large Reynolds numbers." Journal of Fluid Mechanics, Vol. 41, No. 2, pp. 453-480. https://doi.org/10.1017/S0022112070000691
  4. Hafsia, Z., Hadj, M.B., Lamloumi, H., and Maalel, K. (2009). "Internal inlet for wave generation and absorption treatment." Coastal Engineering, Vol. 56, No. 9, pp. 951-959. https://doi.org/10.1016/j.coastaleng.2009.05.001
  5. Lee, C.H., Cho, Y.-S., and Yum, K. (2001). "Internal generation of waves for extended Boussinesq equations." Coastal Engineering, Vol. 42, No. 2, pp. 155-162. https://doi.org/10.1016/S0378-3839(00)00056-9
  6. Lee, C.H., and Suh, K.D. (1998). "Internal generation of waves for time-dependent mild-slope equations." Coastal Engineering, Vol. 34, No. 1-2, pp. 35-57. https://doi.org/10.1016/S0378-3839(98)00012-X
  7. Li, B. (2008). "A 3-D model based on Navier-Stokes equations for regular and irregular water wave propagation." Ocean Engineering, Vol. 35, No. 17-18, pp. 1842-1853. https://doi.org/10.1016/j.oceaneng.2008.09.006
  8. Lin, P. (2008). Numerical modeling of water waves. Taylor & Francis, London and New York.
  9. Lin, P., and Liu, P.L.-F. (1998). "A numerical study of breaking waves in the surf zone." Journal of Fluid Mechanics, Vol. 359, No. 1, pp. 239-264. https://doi.org/10.1017/S002211209700846X
  10. Lin, P., and Liu, P.L.-F (1999). "Internal wave-maker for Navier-Stokes equations models." Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 125, No. 4, pp. 207-215. https://doi.org/10.1061/(ASCE)0733-950X(1999)125:4(207)
  11. Lin, P., and Liu, P. L.-F. (2004). Discussion of "Vertical variation of the flow across the surf zone." Coastal Engineering, Vol. 50, No. 3, pp. 161-164. https://doi.org/10.1016/j.coastaleng.2003.09.002
  12. Liu, D., and Lin, P. (2008). "A numerical study of threedimensional liquid sloshing in tanks." Journal of Computational Physics, Vol. 227, No. 8, pp. 3921-3939. https://doi.org/10.1016/j.jcp.2007.12.006
  13. Liu, D., and Lin, P. (2009). "Three-dimensional liquid sloshing in a tank with baffles." Ocean Engineering, Vol. 36, No. 2, pp. 202-212. https://doi.org/10.1016/j.oceaneng.2008.10.004
  14. Nwogu, O. (1993). "Alternative form of Boussinesq equations for nearshore wave propagation." Journal ofWaterway, Port, Coastal, Ocean Engineering, Vol. 119, No. 6, pp. 618-638. https://doi.org/10.1061/(ASCE)0733-950X(1993)119:6(618)
  15. Pope, S.B. (2000) Turbulent Flows. Cambridge University Press, New York, USA.
  16. Smagorinsky, J. (1963). "General circulation experiments with the primitive equations: I. The basic equations." Monthly Weather Review, Vol. 91, No. 3, pp. 99-164. https://doi.org/10.1175/1520-0493(1963)091<0099:GCEWTP>2.3.CO;2
  17. Wei, G., and Kirby, J.T. (1995). "Time-dependent numerical code for extended Boussinesq equations." Journal ofWaterway, Port, Coastal and Ocean Engineering, Vol. 121, No. 5, pp. 251-261. https://doi.org/10.1061/(ASCE)0733-950X(1995)121:5(251)
  18. Wei, G., Kirby, J.T., and Sinha, A. (1999). "Generation of waves in Boussinesq models using a source function method." Coastal Engineering, Vol. 36, No. 4, pp. 271-299. https://doi.org/10.1016/S0378-3839(99)00009-5

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