Fluid mechanics

The aim of this course is to show that in many material processing and shaping situations, it is necessary to take flow into account, and therefore to tackle the "Fluid Mechanics" aspect often associated with Heat Transfer, Chemistry and Electromagnetism. The basics of the formalism will be covered, and a number of practical results ("pressure drops", velocity fields, injection front position) will be established in academic configurations that are nonetheless representative of realistic situations. Numerical simulation results will be used to illustrate the course, as well as analyses of real-life cases.

Bac +2 physics (point mechanics, basic continuum mechanics, electromagnetism, heat transfer)
Mathematics for engineers Bac +2 (vector analysis, partial differential equations)

Introduction

"Visual" demonstration (creation of a micro-vacuum during injection in a fibrous medium)
Fluid classification
Flow classification / terminology

A general industrial example: Electrical glassmaking
Another example: Wet Plasma Spraying (nanodeposits)




Formalism(s)

Equations of Conservation of Mass and Quantity of Motion
Viscous fluid
Porous medium
Boundary conditions


Applications

Flow calculation in a flat or cylindrical die (Polymer extrusion die)
Estimation of film thickness deposited by gravitational coating (steel and paper industry applications)
Planar or radial injection in porous media (RTM process for composites production)


Supplements - Synthesis

From laminar to turbulent flow
Synthesis exercise (sedimentation of charges in a viscous medium : infondus in glass, iron and steel industry)
Distributed and singular pressure losses: illustration during die shrinkage


Illustrations / Analysis of results obtained with numerical code

Introduction : basic principle of a code
Examples with comments:

Injection of a fluid into a die (empty or with porous mat)
Convection and solidification
Sedimentation of solid particles in a fluid
Impact and solidification of drops on a cooled substrate

Physics

Mécanique Expérimentale des Fluides, Dynamique des Fluides Réels" R. COMOLET, Tome II MASSON Ed.
"Fluides en Ecoulement, Méthodes et modèles", J. PADET, MASSON Ed. Fluides en Ecoulement, Méthodes et modèles", J. PADET, MASSON Ed.
" Dynamique des Fluides", Inge L. RYHMING, Presses Poly. Romandes
"La Mise en Forme des Matières Plastiques", J.F. Agassant et al, TECetDOC Lavoisier, 1986 (reed. 1996)
" Modélisation Numérique en Science et Génie des Matériaux", M. Rappaz et al, Presses Poly. et Univ. Romandes, 1998