Vulnerabilite des ouvrages hydrauliques a travers l’erosion interne : modelisation d’un ecoulement diphasique erodant dans un milieu poreux

الملخص EN

Internal erosion is one of the main causes rupture of hydraulic works.

It can be developed under form of two basic phenomena : piping erosion and suffusion, they differ in their geometrical and Hydraulic boundary conditions.

The risk of rupture is consequently different.

The first phenomenon is the most dangerous and fastest, if it is not immediately stopped; it leads (drove) very quickly to the failure.

In the second, the permeability of the medium is slowly modified and after an uninterrupted phase of development, there (can) may be rupture.

Relying on a Darcy flow and law erosion of Papamichos and a law of evolution of the viscosity fluid (Einstein relation), we propose a first approach for modeling the suffusion by the description of the evolution in time of the average porosity of the matrix solid porous medium, the concentration of fluid particles eroded, as well as the evolution of the mass of particles eroded, while highlighting the influence of changes in hydraulic and mechanical parameters of the ground on this development as that the coefficient of erosion, the maximum porosity...

etc.

The numerical solution of the problem is done by the method of finite differences.

The sample is discretized into a set of elementary layers.

The basic layer is referenced by the index j and the time by exposing i.

For the discretization, we adopted the explicit scheme decentered.

The simulation results indicate that.

The suffusion phenomenon is strongly related to hydraulic and mechanical parameters of soil like the erosion coefficient λ and the final porosity nmax.

Our work is based on the realization of a software using Matlab to study the static or dynamic, linear and rotary electric machines and more particularly the squirrel cage induction motor.

These machines are the most common versions of classic electrical machines in every energy system.

In this paper, we focus on the implementation of the LEC_RBR software developed in Electrotechnic Laboratory of Constantine for the determination of the electrical and the magnetic quantities in the squirrel cage induction motor.