A Fluid-Particle Interaction Method for the Simulation of Particle-Laden Fluid Problems
A.C.S. Fernandes1; H.C. Gomes1; E.M.B. Campello1; P.M. Pimenta1
1 Polytechnic School at University of São Paulo
doi:10.20906/CPS/CILAMCE2017-0139
Resumo
This work proposes a new method for solving coupled problems of fluid mechanics and discrete particle mechanics. The idea is based on previous works by Gomes and Pimenta [1] and Campello [2], and the goal is to develop an efficient computational model suited to simulate problems involving flowing fluid media laden with solid particles or grains. We are especially interested in the simulation of percolation flow through porous media, as well as rock defragmentation caused by underwater drilling processes, to mention a few. The fluid problem is resolved by a standard finite element approach using local element velocity-pressure pairs satisfying the LBB compatibility condition, with the resulting nonlinear system of equations being iteratively solved by the Newton-Raphson method. As an important feature, the fluid mesh remains fixed during the flow, just as in classical Eulerian approaches, and its interface conditions with the (nonmatching) particles´ or grains´ boundaries are imposed through discontinuous piecewise constant Lagrange multipliers interpolating functions [1]. An implicit, staggered interactive and iterative scheme is adopted to achieve convergence within each time step. The particles´ problem, in turn, is resolved in a discrete element approach, wherein both grain-to-grain and grain-to-wall (fixed boundaries) contacts are fully permitted and resolved. The influence of the fluid on the motion of the particles is represented by means of forces, which are computed from the fluid flow and imposed on the particles in a coupled, iterative way. In order to illustrate the potentialities of the proposed scheme, steady and unsteady flow simulations are presented. [1] GOMES, H. C.; PIMENTA, P. M. Embedded interface with discontinuous Lagrange multipliers for fluid-structure interaction analysis. International Journal for Computational Methods in Engineering Science and Mechanics, v. 16, p. 98-111, 2015. [2] CAMPELLO, E. M. B. A description of rotations for DEM models of particle systems. Computational Par
Palavras-chave: Finite Element Method; Fluid-Particles Interaction; Discrete Element Method; Embedded Interfaces