AbstractIn this paper, a three-dimensional (3D) tsunami flow model was proposed in order to predict a 3D flow field around a harbor accurately when tsunami strikes. In the proposed numerical model, the Cartesian coordinate system was adopted, and the Fractional Area/Volume Obstacle Representation (FAVOR) method, which has the ability to impose boundary conditions smoothly at complex boundaries, was introduced into the governing equations in consideration of applying the estimation to actual harbors with complex shape in the future. Moreover, the fifth-order Weighted Essentially Non- Oscillatory (WENO) scheme, which is a technique for achieving high accuracy even if the calculation mesh is coarse, was applied to discretization of the convection terms of the governing equations. In order to verify the validity of the model, it was applied to a large-scale laboratory experiment with a scale model of harbor. Comparisons between the simulated and experimental results showed that the model was able to reproduce the time variation of the flow field with sufficient accuracy. Moreover, the simulated results showed that a complex 3D flow field with some vertical vortex flows was generated around a harbor when tsunami struck.
Apotsos, A., Buckley, M., Gelfenbaum, G., Jaffe, B. and Vatvani, D. 2011. Nearshore tsunami inundation model validation: toward sediment transport applications, Pure and Applied Geophysics, 168, 2097-2119.
Fujii, N., Ikeno, M., Sakakiyama, T., Matsuyama, M., Takao, M. and Mukohara, T. 2009. Hydraulic experiment on flow and topography change in harbor due to tsunami and its numerical simulation, J. Japan Society of Civil Eng., B2-65 (1), 291-295 (in Japanese with English abstract).
Gelfenbaum, G., Vatvani, D., Jaffe, B. and Dekker, F. 2007. Tsunami inundation and sediment transport in vicinity of coastal mangrove forest, Coastal Sediments 07, 2, 1117-1128.
Hirt, C. W. and Sicilian, J. M. 1985. A porosity technique for the definition obstacle in rectangular cell meshes, Proc. 4th Int. Conf. Numerical Ship Hydrodynamics, Washington, D.C., 1-19.
Jiang, G.-S. and Shu, C.-W. 1996. Efficient Implementation of Weighted ENO Schemes, J. Comput. Phys., 126 (1), 202-228.
Kajikawa, Y. and Kuroiwa, M. 2017. Numerical Simulation of 2D topography change in harbor due to tsunami using high order WENO scheme, Proc. 9th Int. Conf. APAC 2017, 527-538.
Li, L., Qiu, Q. and Huang, Z. 2012. Numerical modeling of the morphological change in Lhok Nga, west Banda Aceh, during the 2004 Indian Ocean tsunami: understanding tsunami deposits using forward modeling method, Natural Hazards, 64, 1549-1574.
Matsubara, Y., Kuroiwa, M., Shibutani, Y., Ichimura, Y. and Yonemura, S. 2013. Damage investigation of the Pacific coast of Tohoku Earthquake Tsunami in the Yuriage harbor using small side scan sonar, 68th Annual Conference of Japan Society of Civil Engineers, II-185, 369-370 (in Japanese).
Shu, C.-W. 2003. High order finite difference and finite volume WENO schemes and Discontinuous Galerkin methods for CFD, Int. J. Comput. Fluid Dynamics, 17 (2), 107-118.
Spalding, D. B. 1972. A novel finite difference formulation for differential expressions involving both first and second derivatives, Int. J. Numerical Methods in Eng., 4, 551-559.
Sugawara, D., Goto, K. and Imamura, F. 2014. Sediment transport due to the 2011 Tohoku-oki tsunami at Sendai: Results from numerical modeling, Marine Geology, 358, 18-37.
Sugiyama, H., Akiyama, M., Kamezawa, M., and Nobuchi, D. 1997. The numerical study of turbulent structure in compound open channel flow with variable depth floodplain, J. Hydraul, Coastal, Env. Eng., JSCE, 556 (II-39), 73-83 (in Japanese with English abstract).
Takahashi, T., Shuto, N., Imamura, F. and Asai, D. 2000. Modeling sediment transport due to tsunami with exchange rate between bedload layer and suspended load layer, Proc. Int. Conf. Coastal Eng. 2000, 1508-1519.
Ushijima, S. and NEZU, I. 2002. Computational method for free-surface flows on collocated grid with moving curvilinear coordinates, J. Hydraul., Coastal, Env. Eng., JSCE, 698 (II-58), 11-19 (in Japanese with English abstract).