Direct Numerical Simulation of Particulate Flows with Collisions
- Date: 03/19/2008
Anthony Wachs, Institut Francais du Petrole
University of British Columbia
The comprehension of fluid/solid interactions in moderately to
highly concentrated particulate flows is still limited even if the
fluid is Newtonian and particles are assumed to be ideal spheres (or
circular cylinders in 2D modelling). M
ost of the complexity relies on the various scales in the process: from
the particle to the flow domain, and the corresponding momentu
m transfers. As the solid fraction exceeds a certain critical value
(which lies in the range 5 to 8%), the probability of collisions b
etween particles grows non-negligible and a proper treatment of all
multi-body collisions is required in the modelling of the system.
Here, we present an original numerical approach to address particulate
flows with collisions based on the coupling of a Discrete Eleme
nts method for the solid part and a standard Finite Elements solver for
the fluid part. Coupling is achieved by a Distributed Lagrange
Multiplier/Fictitious Domain method. Our numerical strategy highlights
some promising ^M
capabilities to survey a large number of particulate flow problems
without any restriction on the size, the shape (which is constraine
d to be at least convex) or the polydispersity of the suspension as
well as the rheological properties of the suspending fluid. Result
s on the 2D sedimentation of isometric polygonal particles in a
Newtonian fluid as well as new 3D results give a flavour of what can b
e expected from this type of approach.
Complex Fluids Seminar
