Erwan Bertevas

• PhD (University of Sydney)
• Research and Developement Engineer at IRT Jules Verne (Jules Verne Institute)

Fluids-containing particles are called suspensions and are encountered in natural, biological, and industrial materials. A large number of examples are blood, paint, slurries, mineral concentrates, mine tailings, clay, cement, and fiber-reinforced polymeric resin. One speaks of a suspension when the typical dimension of the suspended particles diff...

The perturbation technique based on the retardation-motion expansion is a simple method to obtain flow solutions at low Weissenberg number. In this context, this perturbation analysis is used to develop simple expressions for the motion of fibers suspended in viscoelastic fluids. In particular, the suspending fluid is characterized by a second-orde...

To provide data for the numerical modelling effort on the impact of seabed nodule harvesting on the marine environment and infrastructure, an experimental study of the interaction between a simple lab-scale nodule harvester and sediment/sand is carried out. The lab-scale harvester is simplified by a moving inclined plate and the seabed sediment is...

A smoothed particle hydrodynamics method is employed to study the mechanical and thermal behaviors of a fiber-filled composite with an anisotropic thermal conductivity (which is coupled to the orientation of the fibers) in a three-dimensional printing process for one- and two-layer deposition. Using a microstructure-based fiber suspension model wit...

The mechanical and thermal behavior of nonisothermal fiber-filled composites in a three-dimensional printing process is studied numerically with a smoothed particle hydrodynamics method. A classical microstructure-based fiber suspension model with a temperature-dependent power-law viscosity model and a microstructure constitutive model is implement...

A Smoothed Particle Hydrodynamics (SPH) formulation and implementation of the classical two-phase mixture model are reported, with a particular focus on the turbulent sediment transport and the sediment disturbances generated by moving equipment operating near or on the seabed. In the mixture model, the fluid-particle system is considered to be an...

We present a numerical study of the fused deposition modeling 3D printing process of fiber-reinforced polymers by means of Smoothed Particle Hydrodynamics (SPH). For this purpose, a classical microstructure-based fiber suspension model coupled with a constitutive model for the suspending polymer is implemented within an SPH framework. The chosen mo...

The cell model (or self-consistent scheme) has been largely used to estimate the bulk thermal properties for dilute slender rods embedded in a matrix by applying a thermal gradient perpendicular to the main axis of the rod. This approach is then extended by considering a thermal gradient along the particle, or in other words a thermal flux through...

The dynamics of Newtonian and pseudoplastic yield-stress fluid drops impacting on solid surfaces are studied numerically by the many body dissipative particle dynamics (MDPD) method. The pseudoplastic yield stress fluid is modelled by two groups of different MDPD particles, in which the parameters are tuned so that the overall fluid behaves in a si...

A rheological constitutive law is developed for a suspension of rigid rods in a Bingham fluid for volume fractions ranging up to the semiconcentrated regime. Based on a cell model approach, which allows expressing the shear stress on the particle surface, the particle stress contribution is derived and involves additional yield stress terms related...

Anisotropic diffusion phenomenon in fluids is simulated using smoothed particle hydrodynamics (SPH). A new SPH approximation for diffusion operator, named anisotropic SPH approximation for anisotropic diffusion (ASPHAD), is derived. Basic idea of the derivation is that anisotropic diffusion operator is first approximated by an integral in a coordin...

Following Leal who gave the motion of a slender axisymmetric rod in a second-order fluid, we derived a complete rheological constitutive equation for dilute and semidilute slender rod suspensions in a viscoelastic solvent based on a cell model. Numerical solutions for the Fokker-Planck equation are obtained for simple shear flows at low and large P...

In the present article, the cell model (or self-consistent scheme) is used to derive constitutive equations for rod suspensions in non-Newtonian viscous matrices such as power-law, Ellis and Carreau fluids. It is found that the shear-thinning character of the matrix influences considerably the rod contribution to the stress tensor, but has no impac...

A constitutive model to predict the behaviour of noncolloidal spherical particle suspensions in Newtonian fluids at low Reynolds number is proposed. The particle contribution to the stress is assumed to primarily arise from pair interactions and is derived based on the motion of an isolated pair of particles which is perturbed by a surrounding effe...

We present the results of measuring the three viscometric functions [the relative viscosity eta(r), and the first (N-1) and second (N-2) normal stress differences] for nominally monosize sphere suspensions in a silicone fluid, which is nominally Newtonian. The measurements of eta(r) and N-1 - N-2 were made with a parallel-plate rheometer, while we...

The first objective of this study is to characterise the physico-chemical and mechanical properties of thermoplastic elastomers (TPE) and their constituents. In parallel with the experimental study, a model describing the mechanical behaviour of such materials at room temperature and without damage is proposed. The composite materials studied in th...

A simulation algorithm was developed to predict the rheological properties of oblate spheroidal suspensions. The motion of each particle is described by Jeffery’s solution, which is then modified by the interactions between the particles. The interactions are considered to be short range and are described by results from lubrication theory and by a...

La caractérisation expérimentale et la modélisation du comportement mécanique à l'état solide d'élastomères thermoplastiques (TPE) constitués d'une matrice en polypropylène isotactique (iPP) et de particules de caoutchouc recyclé sont présentées. L'observation au microscope électronique à balayage révèle que le matériau est constitué de particules...