Importance of Initial Particle Distribution in Modeling Dam Break Analysis with SPH

다국어 초록 (Multilingual Abstract)

Smoothed-Particle Hydrodynamics (SPH) has drawn a great deal of attention in recent years to model various phenomena in engineering and science. SPH is a Lagrangian model in which moving particles represent the fluid body during simulation. Therefore, the initial distribution of particles may affect the model results along with the simulation, and a good initial condition can minimize numerical errors or increase the computational efficiency. Since SPH model particle distributions need a flow pattern, the dam break flow as a classic benchmark SPH problem is selected in this study, and the best initial particle distribution for this case has to be found. Different results, including the mean density of particles, hydrostatic and dynamic pressures and surge front position, are considered the main model results for the adequacy of different initial particle distributions to be discussed. All models are verified at first by simulating different test cases and comparing the results with analytical and experimental data. Acceptable agreements between these data show the model's capability in well predicting the dam break flows. Then, the effects of initial particle distribution on the results are investigated by considering five different particle distributions. For this purpose, Body-Centered Cubic (BCC), Simple Cubic (SC), Greedy, Voronoi Tessellation and Fibonacci algorithms for particle distributions have been modeled. To get reliable conclusions, these distributions have been utilized in models with different kernel functions as well as with different particle spacings. Based on the results, irregular arrangements such as Greedy distribution perform better than regular SC and BCC distributions in modeling dam-break flow. In addition, both Voronoi and Fibonacci distributions perform almost the same with a moderate level of accuracy. Regarding mentioned arrangements, the main outcome of this study, is that the initial particle distribution is an important issue in SPH models, which clearly affects the results.