13,946 research outputs found
Spinodal decomposition of off-critical quenches with a viscous phase using dissipative particle dynamics in two and three spatial dimensions
We investigate the domain growth and phase separation of
hydrodynamically-correct binary immiscible fluids of differing viscosity as a
function of minority phase concentration in both two and three spatial
dimensions using dissipative particle dynamics. We also examine the behavior of
equal-viscosity fluids and compare our results to similar lattice-gas
simulations in two dimensions.Comment: 34 pages (11 figures); accepted for publication in Phys. Rev.
Direct simulation of liquid-gas-solid flow with a free surface lattice Boltzmann method
Direct numerical simulation of liquid-gas-solid flows is uncommon due to the
considerable computational cost. As the grid spacing is determined by the
smallest involved length scale, large grid sizes become necessary -- in
particular if the bubble-particle aspect ratio is on the order of 10 or larger.
Hence, it arises the question of both feasibility and reasonability. In this
paper, we present a fully parallel, scalable method for direct numerical
simulation of bubble-particle interaction at a size ratio of 1-2 orders of
magnitude that makes simulations feasible on currently available
super-computing resources. With the presented approach, simulations of bubbles
in suspension columns consisting of more than fully resolved
particles become possible. Furthermore, we demonstrate the significance of
particle-resolved simulations by comparison to previous unresolved solutions.
The results indicate that fully-resolved direct numerical simulation is indeed
necessary to predict the flow structure of bubble-particle interaction problems
correctly.Comment: submitted to International Journal of Computational Fluid Dynamic
Fluid-Structure Interaction Simulation of a Coriolis Mass Flowmeter using a Lattice Boltzmann Method
In this paper we use a fluid-structure interaction (FSI) approach to simulate
a Coriolis mass flowmeter (CMF). The fluid dynamics are calculated by the open
source framework OpenLB, based on the lattice Boltzmann method (LBM). For the
structural dynamics we employ the open source software Elmer, an implementation
of the finite element method (FEM). A staggered coupling approach between the
two software packages is presented. The finite element mesh is created by the
mesh generator Gmsh to ensure a complete open source workflow. The Eigenmodes
of the CMF, which are calculated by modal analysis are compared with
measurement data. Using the estimated excitation frequency, a fully coupled,
partitioned, FSI simulation is applied to simulate the phase shift of the
investigated CMF design. The calculated phaseshift values are in good agreement
to the measurement data and verify the suitability of the model to numerically
describe the working principle of a CMF
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