• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3B
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• pp.289-301
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• 2009

In this work, wave run-up heights and resultant wave forces on a vertical revetment due to tsunami (solitary wave) are investigated numerically using a numerical wave tank model called CADMAS-SURF (CDIT, 2001. Research and Development of Numerical Wave Channel (CADMAS-SURF). CDIT library, No. 12, Japan.), which is based on a 2-D Navier-Stokes solver, coupled to a volume of fluid (VOF) method. The third order approximate solution (Fenton, 1972. A ninth-order solution for the solitary wave. J. of Fluid Mech., Vol. 53, No.2, pp.257-271) is used to generate solitary waves and implemented in original CADMAS-SURF code. Numerical results of the wave profiles and forces are in good agreements with available experimental data. Using the numerical results, the regression curves determined from the least-square analysis are proposed, which can be used to determine the maximum wave run-up height and force on a vertical revetment due to tsunami. In addition, the capability of CADMAS-SURF is demonstrated for tsunami wave forces acting on an onshore structure using various configuration computations including the variations of the crown heights of the vertical wall and the position of the onshore structure. Based on the numerical results such as water level, velocity field and wave force, the direct effects of tsunami on an onshore structure are discussed.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.63-69
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• 2015

In this study, a 2D hydrodynamic model equipped with critical dry depth scheme was developed to reproduce the flow over staircase. The channel geometry of hydraulic experiment conducted by Ishigaki et al. was generated in the computational space, and the developed model was validated against flow properties such as discharge, velocity and momentum. In addition, the water surface profile and the velocity distribution evolved in flow over two layers staircases were analyzed. When the initial water depth at the upper floor was 0.3 m, the maximum velocity at lower floor was 4.2 m/s, and the maximum momentum was $1.2m^3/s^2$, and its conversion to force per unit width was 1.2 kN/m. This value was equivalent to the hydrostatic force with 50 cm water depth, and evacuation became difficult, as proposed by Ishigaki et al. For the flow over staircases connecting two layers, the maximum run-up height in flat part connecting two layers was approximately two times higher than the initial water depth in upper floor, and the rapid shock wave with sharp front and long tail was propagated.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.145-152
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• 2008

The initial wave lengths of tsunamis can be several tens to hundreds kilometers. Thus, the importance of the frequency dispersive effects in proportion to variation of the wave length, and should be properly considered in numerical simulation of tsunami propagation for a better accuracy. Recently, a practical dispersion-correction scheme has been developed by adding dispersion-correction terms(Cho et al., 2007). The new model employing the numerical technique has been verified by comparing numerical results with available analytic solutions, however, the new model has not yet been applied on a real topography. In this study, the new model is applied on a real topography and its applicability is examined. To study the applicability of the new model, two historical tsunami events are simulated for Sokcho, Mukho and Pohang harbors, with the tide gage records. Numerical results, the arrival time and the maximum water level at the tidal stations, are compared with observed data at each harbor.

• Fire Science and Engineering
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• v.32 no.6
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• pp.69-73
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• 2018

This study examined the reduction effect of a hydrodynamic force acting on the vertical wall of a portable water storage tank with a convex bottom floor. For the numerical simulation, the linearized Peregrine's equation was used to analyze the lapping waves in the tank caused by water falling from a supplying nozzle. The hydrodynamic force could be calculated by measuring the maximum run-up wave height at the vertical wall. The initial conditions of the numerical experiments were set up by controlling the positions and heights of the water supplying nozzle. Finally, the hydrodynamic force acting on the vertical wall can be reduced by the convex bottom design of the portable water storage tank so it can be applied to improve the structural stability.