DOI QR코드

DOI QR Code

고르지 않은 바닥을 지나는 천수 흐름에 대한 유한체적 모형

Finite-Volume Model for Shallow-Water Flow over Uneven Bottom

  • 황승용 (한국건설기술연구원 수자원.환경연구본부 하천해안연구실)
  • 투고 : 2012.09.04
  • 심사 : 2012.10.11
  • 발행 : 2013.02.28

초록

고르지 않은 바닥을 지나는 천수 흐름을 해석하기 위해 천수방정식의 흐름률 경사항과 바닥 경사 생성항에 대해 HLLL 기법과 DFB(Divergence Form for Bed slope source term) 기법을 각각 적용하여 유한체적 모형을 구성하였다. 또한, PSC(Partially Submerged Cell)의 고려를 위해 VFR(Volume/Free-surface Relationship)도 이용하였다. MUSCL에서 WSDGM(Weighted Surface-Depth Gradient Method)을 보다 단순하게 고쳐도 원래의 방법과 정확도가 동등함을 1차원 정상 흐름에 대해 확인하였다. 1차원 PSC에 대한 VFR를 통해 흐름률 경사항과 바닥 경사 생성항의 선평형성이 정확하게 충족됨을 입증하였다. 2차원 PSC에서 DFB 기법으로는 지배방정식의 선평형성이 충족되지 않은 문제를 삼각형 격자에 대한 VFR를 이용하여 해소하였다. 삼각형 턱과 둥근 융기를 지나는 2차원 댐 붕괴 흐름에 대한 모의에서 실험실 실험 결과와 잘 부합됨을 확인하였다. 또한, 부분 댐 붕괴 흐름에 대한 모형의 적용에서 경사면은 물론 불규칙 바닥에서도 요철의 잠김이 성공적으로 모의되었다. 따라서 고르지 않은 실제 하천 지형에 대한 이 모형의 적용성이 기대된다.

For analyzing shallow-water flows over the uneven bottom, the HLLL scheme and the divergence form for bed slope source term (DFB) technique, respectively were applied to the flux gradient and the bottom gradient source terms in a finite-volume model for the shallow water equations. And also the model incorporated the volume/free-surface relationship (VFR) to consider the partially submerged cells (PSC). It was identified that a simpler version of the weighted surface-depth gradient method in the MUSCL was equivalent to the original one in the accuracy for 1D steady flows. It was verified that the flux gradient term and the bottom gradient source term were well-balanced exactly by the VFR for the 1D PSC. The VFR for the triangular PSC settled the problem which the governing equations were not well-balanced by the DFB technique for the 2D PSC. There were good agreements in simulations and experiments for 2D dam-break flows over a triangular sill and a round bump. In addition, the partial dam-break flow was successfully simulated for flooding of roughnesses in an irregular bottom as well as a sloping one. Therefore, this model is expected to be applied to the real river with uneven topography.

키워드

참고문헌

  1. Aureli, F., Maranzoni, A., Mignosa, P., and Ziveri, C. (2008a). "A weighted surface-depth gradient method for the numerical integration of the 2D shallow water equations with topography." Advances in Water Resources, Vol. 31, pp. 962-974. https://doi.org/10.1016/j.advwatres.2008.03.005
  2. Aureli, F., Maranzoni, A., Mignosa, P., and Ziveri, C. (2008b). "Dam-break flows: acquisition of experimental data through an imaging technique and 2D numerical modeling." Journal of Hydraulic Engineering, Vol. 134, pp. 1089-1101. https://doi.org/10.1061/(ASCE)0733-9429(2008)134:8(1089)
  3. Batten, P., Lambert, C., and Causon, D.M. (1996). "Positively conservative high-resolution convection schemes for unstructured elements." International Journal for Numerical Methods in Engineering, Vol. 39, pp. 1821-1838. https://doi.org/10.1002/(SICI)1097-0207(19960615)39:11<1821::AID-NME929>3.0.CO;2-E
  4. Begnudelli, L., and Sanders, B.F. (2006). "Unstructured grid finite-volume algorithm for shallow-water flow and scalar transport with wetting and drying." Journal of Hydraulic Engineering, Vol. 132, pp. 371-384. https://doi.org/10.1061/(ASCE)0733-9429(2006)132:4(371)
  5. Begnudelli, L., and Sanders, B.F. (2007). "Conservative wetting and drying methodology for quadrilateral grid finite-volume models." Journal of Hydraulic Engineering, Vol. 133, pp. 312-322. https://doi.org/10.1061/(ASCE)0733-9429(2007)133:3(312)
  6. Bermudez, A., and Vazquez, M.E. (1994). "Upwind methods for hyperbolic conservation laws with source terms." Computers & Fluids, Vol. 23, pp. 1049-1071. https://doi.org/10.1016/0045-7930(94)90004-3
  7. Bradford, S.F., and Sanders, B.F. (2002). "Finite-volume model for shallow-water flooding of arbitrary topography." Journal of Hydraulic Engineering, Vol. 128, pp. 289-298. https://doi.org/10.1061/(ASCE)0733-9429(2002)128:3(289)
  8. Brufau, P., García-Navarro, P., and Vazquez-Cendón, M.E. (2004). "Zero mass error using unsteady wetting- drying conditions in shallow flows over dry irregular topography." International Journal for Numerical Methods in Fluids, Vol. 45, pp. 1047-1082. https://doi.org/10.1002/fld.729
  9. George, D.L. (2004). Numerical approximation of the nonlinear shallow water equations with topography and dry beds: a Godunov-type scheme. MS. thesis, University of Washington.
  10. George, D.L. (2008). "Augmented Riemann solvers for the shallow water equations over variable topography with steady states and inundation." Journal of Computational Physics, Vol. 227, pp. 3089-3113. https://doi.org/10.1016/j.jcp.2007.10.027
  11. Goutal, N. (1997). "Test case 2: steady state validation." Proceedings of the 2nd workshop on dam-break wave simulation, Edited by Goutal, N., and Maurel, F., IAHR,Lisbon, Portugal, pp. 13-17.
  12. Hubbard, M.E., and Garcia-Navarro, P. (2000). "Flux difference splitting and the balancing of source terms and flux gradients." Journal of Computational Physics, Vol. 165, pp. 89-125. https://doi.org/10.1006/jcph.2000.6603
  13. Hwang, S.-Y., and Lee, S.H. (2011). "An application of the multi-slope MUSCL to the shallow water equations." Journal of Korea Water Resources Association, Vol. 44, pp. 819-830(in Korean). https://doi.org/10.3741/JKWRA.2011.44.10.819
  14. Hwang, S.-Y., and Lee, S.H. (2012). "An application of the HLLL approximate Riemann solver to the shallow water equations." Journal of Korea Society of Civil Engineers, Vol. 32, No. 1B, pp. 21-27(in Korean).
  15. Jeong, W., and Kim, K.H. (2011). "A study on inundation simulation in coastal urban areas using a two-dimensional numerical model." Journal of Korea Water Resources Association, Vol. 44, pp. 601-617(in Korean). https://doi.org/10.3741/JKWRA.2011.44.8.601
  16. Kim, D.H., and Cho, Y.S. (2005). "An improved surface gradient method for the computation of hyperbolic- type shallow-water equations on irregular bathymetry." Journal of Korea Society of Civil Engineers, Vol. 25, No. 3B, pp. 223-229(in Korean).
  17. Kim, T.H, Han, K.Y., and Kim, B.H. (2011). "Treatment of the bed slope source term for 2-dimensional numerical model using quasi-steady wave propagation algorithm." Journal of Korea Water Resources Association, Vol. 44, pp. 145-156(in Korean). https://doi.org/10.3741/JKWRA.2011.44.2.145
  18. Lee, K.S., and Lee, S.-T. (1988). "Two-dimensional finitevolume unsteady-flow model for shocks." Journal of Korea Water Resources Association, Vol. 31, pp. 279- 290(in Korean).
  19. LeVeque, R.J. (1998). "Balancing source terms and flux gradients in high-resolution Godunov methods: the quasi-steady wave-propagation algorithm." Journal of Computational Physics, Vol. 146, pp. 346-365. https://doi.org/10.1006/jcph.1998.6058
  20. LeVeque, R.J. (2002). Finite volume method for hyperbolic problems. Cambridge University Press.
  21. Maurel, F. (1997). "Test case 1: momentum equation source terms calculation-1D codes." Proceedings of the 2nd workshop on dam-break wave simulation, Edited by Goutal, N., and Maurel, F., IAHR, Lisbon, Portugal, pp. 2-5.
  22. Pu, J.H., Cheng, N.-S., Tan, S.K., and Shao, S. (2012) "Source term treatment of SWEs using surface gradient upwind method." Journal of Hydraulic Research, Vol. 50, pp. 1-9. https://doi.org/10.1080/00221686.2012.659026
  23. Soares-Frazão, S. (2007). "Experiments of dam-break wave over a triangular bottom sill." Journal ofHydraulic Research, Vol. 45, pp. 19-26. https://doi.org/10.1080/00221686.2007.9521829
  24. Toro, E.F. (2001). Shock-capturing methods for freesurface shallow flows. John Wiley & Sons.
  25. Valiani, A., and Begnudelli, L. (2006). "Divergence form for bed slope source term in shallow water equations." Journal of Hydraulic Engineering, Vol. 132, pp. 652- 665. https://doi.org/10.1061/(ASCE)0733-9429(2006)132:7(652)
  26. Valiani, A., Caleffi, V., and Zanni, A. (2002). "Case study: Malpasset dam-break simulation using a two-dimensional finite volume method." Journal of Hydraulic Engineering, Vol. 128, pp. 460-472. https://doi.org/10.1061/(ASCE)0733-9429(2002)128:5(460)
  27. van Leer, B. (1979). "Towards the ultimate conservative difference scheme V. a second order sequel to Godunov's method." Journal of Computational Physics, Vol. 32, pp. 101-136. https://doi.org/10.1016/0021-9991(79)90145-1
  28. van Leer, B. (2006). "Upwind and high-resolution method for compressible flow: from donor cell to residualdistribution schemes." Communications in Computational Physics, Vol. 1, pp. 192-206.
  29. Vazquez-Cendón, M.E. (1999). "Improved treatment of source terms in upwind schemes for the shallow water equations in channels with irregular geometry." Journal of Computational Physics, Vol. 148, pp. 497-526. https://doi.org/10.1006/jcph.1998.6127
  30. Woo, H. (2001). River Hydraulics. Cheong Moon Gak Publishers(in Korean).
  31. Zhou, J.G., Causon, D.M., Mingham, C.G., and Ingram, D.M. (2001). "The surface gradient method for the treatment of source terms in the shallow-water equations." Journal of Computational Physics, Vol. 168, pp. 1-25. https://doi.org/10.1006/jcph.2000.6670

피인용 문헌

  1. Effect of Corrected Hydrostatic Pressure in Shallow-Water Flow over Large Slope vol.47, pp.12, 2014, https://doi.org/10.3741/JKWRA.2014.47.12.1177
  2. 2D Numerical Simulations for Shallow-water Flows over a Side Weir vol.48, pp.11, 2015, https://doi.org/10.3741/JKWRA.2015.48.11.957