Abstract
This paper investigates the cause of the spurious waves generated at the domain boundaries and proposes robust absorbing conditions in 2D shallow water simulations. The spurious waves are caused by the missing information when imposing boundary conditions for subcritical flows over irregular topography adjacent to the boundaries. The resulting boundary disturbances are likely to affect the flow solution inside the domain. To prevent the generation of such boundary spurious waves, an approach is proposed by extending the computational domain in the normal direction by a small number of cells. The number of extended cells is properly determined through numerical experiments by taking into account the effects of wave height, water depth, boundary topographic features (i.e., bump height, bump slope and bump type) and grid resolution. Five extended cells are found to be adequate in eliminating the spurious waves and maintaining stable and accurate numerical solutions. The robustness of the proposed boundary treatment is tested and confirmed through applications to reproduce two field-scale tsunami events.
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References
Akan AO (2006) 2-Energy and momentum principles. In: Akan AO (ed) Open channel hydraulics. Butterworth-Heinemann, Oxford, pp 24–66
Blayo E, Debreu L (2005) Revisiting open boundary conditions from the point of view of characteristic variables. Ocean Model 9(3):231–252
Bussing TR, Murmant EM (1988) Finite-volume method for the calculation of compressible chemically reacting flows. AIAA J 26:1070–1078
Chen X, Liu C, O’Driscoll K, Mayer B, Su J, Pohlmann T (2013) On the nudging terms at open boundaries in regional ocean models. Ocean Model 66:14–25
Gallacher P, Hebert D, Schaferkotter M (2011) Nesting a nonhydrostatic model in a hydrostatic model: the boundary interface. Ocean Model 40(2):190–198
Hou J, Liang Q, Simons F, Hinkelmann R (2013a) A 2D well-balanced shallow flow model for unstructured grids with novel slope source term treatment. Adv Water Resour 52:107–131
Hou J, Simons F, Mahgoub M, Hinkelmann R (2013b) A robust well-balanced model on unstructured grids for shallow water flows with wetting and drying over complex topography. Comput Methods Appl Mech Eng 257:126–149
Leveque RJ (2002) Finite volume methods for hyperbolic problems. Cambridge university press, Cambridge
Liang Q (2011) A structured but non-uniform cartesian grid-based model for the shallow water equations. Int J Numer Methods Fluids 66(5):537–554
Liang Q (2012) A simplified adaptive cartesian grid system for solving the 2D shallow water equations. Int J Numer Methods Fluids 69(2):442–458
Nycander J, Döös K (2003) Open boundary conditions for barotropic waves. J Geophys Res 108(C5):3168
Oddo P, Pinardi N (2008) Lateral open boundary conditions for nested limited area models: a scale selective approach. Ocean Model 20(2):134–156
Sheng J, Greatbatch RJ, Zhai X, Tang L (2005) A new two-way nesting technique for ocean modeling based on the smoothed semi-prognostic method. Ocean Dyn 55(3–4):162–177
Synolakis CE, Bernard EN, Titov VV, Kanoglu U, Gonzalez FI (2007) Standards, criteria, and procedures for NOAA evaluation of tsunami numerical models. NOAA Technical Memorandum OAR PMEL-135. NOAA/Pacific Marine Environmental Laboratory, Seattle
Zhou JG, Causon DM, Mingham CG, Ingram DM (2001) The surface gradient method for the treatment of source terms in the shallow-water equations. J Comput Phys 168:1–25
Zhou JG, Causon DM, Ingram DM, Mingham CG (2002) Numerical solutions of the shallow water equations with discontinuous bed topography. Int J Numer Methods Fluids 38:769–788
Acknowledgments
The authors acknowledge the support from the Royal Society under the International Exchanges 2013 NSFC cost share scheme (IE131297). This work is also partly supported by the National Natural Science Foundation of China through research grant (No. 51379074) and the Chinese Government through the ‘Recruitment Program of Global Experts’. The authors also thank Professor Tomohiro Yasuda from Kyoto University for providing the data for the second benchmark test.
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Hou, J., Liang, Q. & Xia, X. Robust absorbing boundary conditions for shallow water flow models. Environ Earth Sci 74, 7407–7422 (2015). https://doi.org/10.1007/s12665-015-4743-6
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DOI: https://doi.org/10.1007/s12665-015-4743-6