Overview

Raphael Lardat and Alain Dervieux
INRIA, Sophia-Antipolis, France

Bruno Koobus
Department of Mathematics, Universit de Montpellier II, France

Eric Schall
IUT G nie Thermique et Energ tique, Universit de Pau, France

Charbel Farhat
Department of Aerospace Engineering Sciences, University of Colorado at Boulder, USA

1. Introduction

Thrust inverters are a crucial device for the reduction of landing distances for commerical aircraft. They involve complex mechanisms: they have to be completely inoperative on the engine flow in any part of the journey except landing; then several pieces have to move in order to allow an efficient deviation of this flow, forcing it to go forward instead of backward. We are therefore talking about a device that is made of several moving pieces that should strongly act on the engine flow. Furthermore, the flow considered is confined in a partly closed box of complex geometry, which results in acoustic phenomena and large recirculations. A significant part of the jet deviation is caused by a flap which endures large forces from the flow. The motivation of our study is to investigate which kind of mechanical coupling can arise in the case of under-dimensioned design of this flap.

For this preliminary study, several geometrical and physical simplifications are introduced. The modelization and software involve a finite-element dynamical shell model for the structure, and a finite-element finite volume upwind Euler model for the flow. Coupling between both models is built through a full ALE formulation for the fluid, and proper transmission of effort through a non-conforming...