2021 Volume 2021 Pages 20210006
The fundamental laws of physics, such as the second law of thermodynamics and the mass conservation law, cannot be satisfied for systems obtained after space discretization, even if the original governing equations satisfy them. To this end, a new weakly compressible particle method with physical consistency was developed in this study. Since the discrete formulations of this method can be fit into the extended Lagrangian mechanics for systems with dissipation, it satisfies the fundamental laws of physics, i.e., physical consistency. The formulations were mostly inherited from the previously developed strictly incompressible particle method, which is also physically consistent. Instead of the implicit algorithm employed in the previous method, an explicit algorithm is employed in the present method for improved calculation efficiency. Static pressure, droplet extension and dam break calculations were conducted, and the ability to predict the pressure and fluid motion was confirmed by comparing with the theory and experimental results. The calculation efficiency was found to be better than that of the implicit algorithm-based strictly incompressible method.
