Development of in/outflow boundary conditions for MPM simulation of uniform and non-uniform open channel flows

Abstract

This paper describes the development and application of inflow and outflow boundary conditions (BCs) for the material point method (MPM) in order to simulate fluid flow problems. This corresponds to velocity and pressure controlled BCs. Due to the coupled Lagrangian and Eulerian description of the fluid motion in MPM it is necessary to add and remove material points, with appropriate kinematic properties, to and from the computational domain. The newly-developed BCs have been used to simulate uniform open channel flow and the phenomenon of free overfall in open channels, which is transient conditions leading to non-uniform flow due to a sudden bed level drop. It is shown that the numerical results predict well the flow geometry including end depth ratio, pressure distribution and accelerations, therefore the velocities and displacements.

Simulation of heat and fluid flow in porous medium and fractures by material point method

“…It should be noted that because the fluid phase uses the Lagrangian material point description, while setting the inflow and outflow boundaries, it is necessary to add a layer of fluid material points outside the inflow boundary and assign identical fluid properties to each of these material points. In addition, the fluid material points that exit the computational domain should be deleted in time (Zhao et al, 2019).…”

A Generalized Interpolation Material Point Method for Shallow Ice Shelves. 1: Shallow Shelf Approximation and Ice Thickness Evolution

“…We note that a more efficient, but complicated, scheme may be implemented, where in the "inflow elements" refill with material points automatically as they become empty (Zhao et al, 2019).…”

“…This scheme is illustrated in Figure 2a , where the material point GIMPM domains are dotted gray, the inflow boundary is indicated by the dotted red line, and elements belonging to the additional inflow domain are highlighted in blue. We note that a more efficient, but complicated, scheme may be implemented, where in the “inflow elements” refill with material points automatically as they become empty (Zhao et al., 2019 ).…”

MPM–FEM hybrid method for granular mass–water interaction problems

“…Nevertheless, only few attempts have so far been made at managing with incompressibility for solidliquid MPM. In addition, the dynamic addition or deletion of water particles is more complicated when it comes to problems containing inflow or outflow boundaries [22,43].…”