We develop and validate a three-dimensional particle method based on an Enhanced Weakly-Compressible MPS approach for modeling immersed dense granular flows. For this purpose, we adopt a generalized rheological model, using a regularized visco-inertial rheology, for all regimes of multiphase granular flow. Moreover, we propose a new consistent formulation to estimate the effective pressure of the solid skeleton based on the continuity equation of the pore-water. To improve the accuracy of the multiphase particle methods, especially near boundaries and interfaces, we introduce a modified high-order diffusive term by employing the convergent form of the Laplacian operator. The effectiveness of the new diffusive term is particularly demonstrated by modeling the hydrostatic pressure of two fluid phases. Further, coupling the generalized rheology model with the flow equations, we investigate the gravity-driven granular flows in the immersed granular collapse and slide in three dimensions. As a part of this study, we represent the experiment on the immersed granular collapse to validate the model. The evolution and runout length of the granular bulk are compared with those from experiments confirming good compatibility. Overall, the qualitative and quantitative results justify the proposed developments shown to be essential for predicting different states of the immersed granular flows.

我们开发并验证了一种基于增强型弱可压缩MPS方法的三维粒子方法，用于对沉浸的密集颗粒流进行建模。为此，我们对多相颗粒流的所有状态采用常规的流变模型，并使用常规的黏性惯性流变技术。此外，我们提出了一个新的一致公式，根据孔隙水的连续性方程估算固体骨架的有效压力。为了提高多相粒子方法的准确性，尤其是在边界和界面附近，我们通过采用Laplacian算子的收敛形式引入了一种改进的高阶扩散项。通过对两个流体相的静水压力进行建模，特别证明了新扩散项的有效性。更多，结合广义流变模型与流动方程，我们研究了沉浸式颗粒塌陷和滑移在三个维度上的重力驱动颗粒流。作为这项研究的一部分，我们对沉浸的颗粒塌陷进行了实验，以验证模型。将粒状散料的演变和跳动长度与来自实验的结果进行了比较，证实了良好的相容性。总体而言，定性和定量结果证明了拟议的开发对证明预测沉浸颗粒流的不同状态至关重要。将粒状散料的演变和跳动长度与来自实验的结果进行了比较，证实了良好的相容性。总的来说，定性和定量的结果证明了拟议的开发是合理的，该开发对于预测沉浸颗粒流的不同状态至关重要。将粒状散料的演变和跳动长度与来自实验的结果进行了比较，证实了良好的相容性。总体而言，定性和定量结果证明了拟议的开发对证明预测沉浸颗粒流的不同状态至关重要。