Numerical simulation of compressible fluid-particle flows in multimaterial Lagrangian hydrodynamics framework

•A fluid-particle multiphase flows model is proposed in Lagrangian-Lagrangian framework. The model discretizes both phases using Lagrangian method, and it has capability from dense to dilute particle environments with complex multimaterial fluids.•For the discrete particle phase, the drag force, pressure gradient force and collision force are considered as dominant forces, and the collision force among particles is solved by coarse-grained DEM, which can give more physical information no matter the particle phase is dense or dilute than traditional particle stress model. For the continuous fluid phase, both the volume fraction of fluid phase and feedback source terms of momentum and energy appear in governing equations, so it is different from pure fluid or dilute particle flows, where the effect of volume fraction and feedback source of particle phase is very small and can be neglected.•The relevant numerical model and approach are integrated to a multimaterial staggered-grid elastic-plastic Lagrangian hydrodynamics code. The computational results are presented, discussed, and shown to agree well with the theoretical solutions or experimental measurements. Those simulations prove that the derived model can be successfully applied to the all pattern particle flows with multimaterial fluids, and the accurate results can be obtained. They provide the confidence in the utility of the model proposed. In the numerical simulation of multimaterial flows, Lagrangian method was applied widely, and fluid-particle multiphase flows phenomenon often existed when elastic-plastic material was impacted intensively. Most of the previous studies about the fluid-particle flows in Lagrangian hydrodynamics framework only focused on the dilute flow. It is very necessary to establish a Lagrangian-Lagrangian coupling numerical simulation framework, which is suitable for both multimaterial and dense particle flows in engineering applications. In present study, a numerical model, in which both continuous fluid phase and dispersed particle phase are discretized in Lagrangian frameworks, is developed. In this model, the effect of particle volume fraction, collision force among particles, interaction and coupling between fluid and particle phases are all considered based on the physical meanings. Therefore it is well-suited to complex multiphase flows including transition between dense and dilute particles flows, and material interfaces and free boundaries in multimaterial flows can b