This study aimed to comprehensively investigate the influence of substrate level difference and material composition on dam break wave evolution over two different erodible beds. Utilizing the Volume of Fluid (VOF) method, we tracked free surface advection and reproduced wave evolution using experimental data from the literature. For model validation, a comprehensive sensitivity analysis encompassed mesh resolution, turbulence simulation methods, and bed load transport equations. The implementation of Large Eddy Simulation (LES), non-equilibrium sediment flux, and van Rijn’s (1984) bed load formula yielded higher accuracy compared to alternative approaches. The findings emphasize the significant effect of substrate level difference and material composition on dam break morphodynamic characteristics. Decreasing substrate level disparity led to reduced flow velocity, wavefront progression, free surface height, substrate erosion, and other pertinent parameters. Initial air entrapment proved substantial at the wavefront, illustrating pronounced air-water interaction along the bottom interface. The Shields parameter experienced a one-third reduction as substrate level difference quadrupled, with the highest near-bed concentration observed at the wavefront. This research provides fresh insights into the complex interplay of factors governing dam break wave propagation and morphological changes, advancing our comprehension of this intricate phenomenon.

中文翻译：

---

具有不同基质水平变化的侵蚀层溃坝水流的数值研究

本研究旨在综合研究基质水平差异和物质成分对两种不同侵蚀层溃坝波演化的影响。利用流体体积 (VOF) 方法，我们跟踪自由表面平流并使用文献中的实验数据再现波浪演化。为了进行模型验证，全面的灵敏度分析包括网格分辨率、湍流模拟方法和床载荷传输方程。与其他方法相比，大涡模拟 (LES)、非平衡沉积物通量和 van Rijn (1984) 床荷公式的实施产生了更高的精度。研究结果强调了基质水平差异和材料成分对溃坝形态动力学特征的显着影响。降低基底水平差异导致流速、波前级数、自由表面高度、基底侵蚀和其他相关参数降低。事实证明，最初的空气截留在波前是大量的，说明了沿着底部界面的明显的空气-水相互作用。随着基质液位差翻两番，屏蔽参数减少了三分之一，在波前观察到了最高的近床浓度。这项研究为控制溃坝波传播和形态变化的因素之间复杂的相互作用提供了新的见解，增进了我们对这一复杂现象的理解。