NUMERICAL MODELING OF BREAKING SOLITARY WAVE RUN UP IN SURF ZONE USING INCOMPRESSIBLE SMOOTHED PARTICLE HYDRODYNAMICS (ISPH) Kourosh Hejazi, K.N. Toosi University of Technology,
[email protected] AmirReza Ghavami, K.N. Toosi University of Technology,
[email protected] Abolfazl Aslani, K.N. Toosi University of Technology,
[email protected] INTRODUCTION Waves breaking in the coastal surf zone and crashing over a sea wall can cause considerable damage to beaches and coastal structures during wave overtopping events (Hu et al., 2000). The experimental and numerical studies for investigating effects of beach roughness on the wave run up are scarce. SOLUTION METHOD The solution method is composed of two steps. In the first step the velocity field is computed without the inclusion of the pressure gradient term. In the second step, the incompressibility is enforced by continuity equation. For the solution of the matrix of the pressure coefficients, the sparse property has been observed. Two methods have been implemented for the friction. In the first method an approach similar to Müller et al. (2004) has been employed to compute the frictional force. In the second method the shear velocity is calculated. RESULTS The simulated results of a solitary wave over a 5% smooth slope have been compared against the measured values of Lin et al. (1999) in Fig 1, where R, a and h represent the run up, wave amplitude and water depth respectively. The simulated results for a breaking solitary wave run up over a slope of 5˚ for smooth and rough surfaces with different Manning coefficients are compared with experimental measurements of Feng (2001) in Fig 2 and 3 for the first and second methods respectively. Both methods show good agreements with closer results of the second method for smooth and n=0.02 conditions and better agreements of the first method for n=0.033.
Figure 2 Wave run up (first method: application of friction by wall function)
Figure 3 Wave run up (second method: application of friction by force equal to coefficient of diffusion) References Feng (2001): Experimental study of the effect of coastal terrain roughness on ocean long wave run up. M.Sc. Thesis, University of Hawaii. Hu, Mingham, Causon (2000): Numerical simulation of wave overtopping of coastal structures using the nonlinear shallow water equations. Coastal Engineering vol. 41, pp. 433–465. Lin, Chang, Liu Philip (1999): Runup and rundown of solitary waves on slopping beaches. Waterway Port, Coast Ocean Engng vol. 125 (5), pp. 247-55. Muller, Shirm, Teschner, Heidelberger, Gross, (2004): Interaction of fluids with deformable solids. Comput. Animat Virtual Worlds vol. 15 (3-4), pp. 159-171.
Figure 1 Comparison of simulated and measured values of solitary wave propagation, breaking and run up
