Numerical Simulation of Two-Phase Water-Oil Flow in a Horizontal Pipe Using the Smoothed Particle Hydrodynamics Method

In this work, the numerical code DualPhysics, based on the Lagrangian particle and mesh free method Smoothed Particle Hydrodynamics, has been employed to solve the slightly compressible isothermal two-phase water-oil flow. The continuity and momentum equations are solved, and we used the modified Tait equation of state to determine the pressure. To validate the numerical code, we solved the modified Couette flow of two fluids. As a practical case, we solved the isothermal and two-dimensional two-phase water-oil flow. The mixing of the fluids occurs after passing through a 45 degree Y junction placed at the entrance of the horizontal pipeline. Results showed the potential for using the numerical code, although some modifications and alterations are still necessary to solve practical problems.

Effects of Van Der Waals Forces on the Vibration of Stacked Multilayered Graphene/Black Phosphorus Heterostructures

In this paper, the vibration of a stacked multilayered graphene/black phosphorus (G/BP) heterostructure is investigated via the mesh-free method. The shape function and its derivatives are addressed by the moving least squares (MLS) approach. Optimization of the sequential quadratic programming method is adopted to calculate the distance between the arbitrary layers. Therefore, coefficients of the van der Waals (vdW) interaction between arbitrary layers of heterostructures are obtained. Then the frequencies and mode shapes of the multilayered G/BP heterostructure, considering the vdW interaction between arbitrary layers, are compared with considering only the vdW interaction among adjacent layers. The effects of the number of layers and aspect ratio of the G/BP heterostructure on the frequencies are investigated. The results demonstrate that coefficients of the vdW interaction, considering the arbitrary layers, are larger than those considering only adjacent layers. The difference between natural frequencies considering arbitrary layers and those considering adjacent layers is not clear for the low-order cases. Alternatively, the difference between natural frequencies obtained considering arbitrary layers and those considering adjacent layers are obvious for high-order cases. This paper provides a useful method to optimize the vdW interaction between multilayered G/BP heterostructures and can adequately simulate their vibration behaviors.

Imitating Simulation of Thermomechanical Processing of Metals

Thermomechanical processing of metals by cutting is a complicated technological problem that is difficult for mathematical simulation. The various phenomena observed in this process are so closely intertwined with each other and their interaction is so complex that eleven relatively independent theories not coming yet to a holistic unity are focused on the cutter edge. These are a theory of chip formation, metal cutting mechanics, a friction theory in metalworking, thermodynamics of cutting, a theory of wear and resistance of cutting tools. A mesh-free method of Smoothed Particle Hydrodynamics (SPH) has been used for simulation in this paper. The SPH-based simulation in LS-DYNA is performed to predict cutting forces and plastic deformations for machining processing of metals by cutting. The results characterizing the distribution patterns of the strain tensor components and the temperature field at different points in time and space have been presented. The performed studies have demonstrated that it is possible to use changes in the temperature fields as a criterion for estimating the elastic-plastic deformations.