arXiv subjects

Roland Glowinski

Publications and source records attributed to Roland Glowinski.

21 records · Page 2Linked to original sources

arXiv2013

Circular band formation for incompressible viscous fluid--rigid particle mixtures in a rotating cylinder

In this paper we have investigated a circular band formation of fluid-rigid particle mixtures in a fully filled cylinder horizontally rotating about its cylinder axis by direct numerical simulation. These phenomena are modeled by the Navier-Stokes equations coupled to the Euler-Newton equations describing the rigid solid motion of the non-neutrally particles. The formation of circular bands studied in this paper is not resulted by mutual interaction between the particles and the periodic inertial waves in the cylinder axis direction (as suggested in Phys. Rev. E, 72, 021407 (2005)), but due to the interaction of particles. When a circular band is forming, the part of the band formed by the particles moving downward becomes more compact due to the particle interaction strengthened by the downward acceleration from the gravity. The part of a band formed by the particles moving upward is always loosening up due to the slow down of the particle motion by the counter effect of the gravity. To form a compact circular band (not a loosely one), enough particles are needed to interact among themselves continuously through the entire circular band at a rotating rate so that the upward diffusion of particles can be balanced by the compactness process when these particles moving downward.

physics.flu-dyn↗

arXiv2012

Fluid-structure interaction in blood flow capturing non-zero longitudinal structure displacement

We present a new model and a novel loosely coupled partitioned numerical scheme modeling fluid-structure interaction (FSI) in blood flow allowing non-zero longitudinal displacement. Arterial walls are modeled by a {linearly viscoelastic, cylindrical Koiter shell model capturing both radial and longitudinal displacement}. Fluid flow is modeled by the Navier-Stokes equations for an incompressible, viscous fluid. The two are fully coupled via kinematic and dynamic coupling conditions. Our numerical scheme is based on a new modified Lie operator splitting that decouples the fluid and structure sub-problems in a way that leads to a loosely coupled scheme which is {unconditionally} stable. This was achieved by a clever use of the kinematic coupling condition at the fluid and structure sub-problems, leading to an implicit coupling between the fluid and structure velocities. The proposed scheme is a modification of the recently introduced "kinematically coupled scheme" for which the newly proposed modified Lie splitting significantly increases the accuracy. The performance and accuracy of the scheme were studied on a couple of instructive examples including a comparison with a monolithic scheme. It was shown that the accuracy of our scheme was comparable to that of the monolithic scheme, while our scheme retains all the main advantages of partitioned schemes, such as modularity, simple implementation, and low computational costs.

math.NA↗

arXiv2003

Computational Techniques for Simulating Natural Convection in Three-Dimensional Enclosures with Tetrahedral Finite Elements

This article discusses computational techniques for simulating natural convection in three-dimensional domains using finite element methods with tetrahedral elements. These techniques form a new numerical procedure for this kind of problems. In this procedure, the treatment of advection by a wave equation approach is extended to three-dimensional unstructured meshes with tetrahedra. Numerical results of natural convection of an incompressible Newtonian fluid in a cubical enclosure at Rayleigh numbers in the range $10^3$ to $10 ^6$ are obtained and they are in good agreement with those in literature obtained by other methods.

math.NA↗