Master thesis and internship[BR]- Master's thesis : Does a hybrid model fluid with solid envelope allow to better approach the flow behavior of a bird than a fluid model during a multi-stage ingestion?[BR]- Integration Internship : Safran Aero Boosters

Abstract

A new multi-material model is proposed for bird substitute to simulate bird ingestion in new generation aircraft engines using LS-DYNA. Three hybrid models are tested and compared with the actual hydrodynamic model. Simulation results are correlated with the experimental data available in terms of visual aspects and theoretical concepts (momentum transfer and steady-state pressure). The numerical method used is the Smoothed-Particle Hydrodynamics. The multi-material models are composed of an external envelope of solid material representing the skin and muscular tissue of the bird with an internal fluid material representing the internal organs, blood, intracellular water, cavities and the skeleton of the bird. The substitutes are composed of the hydrodynamic model for the internal particles. The three substitute models differ in the material model of the external particles: an elasto-plastic hydrodynamic model, an elasto-plastic solid model with damage and failure and a hyperelastic model. After comparison, the multi-material model giving the best results and representing more accurately the flow behavior of a real bird, i.e. the mass and velocity distribution over time, is chosen. An influence study is conducted on the material constants with the aim to find the most appropriate parameters. This new multi-material model presents interesting results and offers a behavior more similar to a real bird compared to the hydrodynamic model. Particularly, this material could enable a better representation of multi-stage impact simulations. However, an optimization of its material parameters is still required.