Position details

Modeling soot production and transport in aeronautic engines
Training › Computational Fluid Dynamics - Combustion

Required Education / Niveau requis

Master or Engineering school

From / Date de début

February/April 2013

Duration / Durée

6 months

Context / Contexte

The formation of soot particles in a combustion chamber is a very complex phenomenon. Generally, the soot formation process is divided into four steps:  first, chemical precursors such as acethylene are produced in the gaseous phase; then Polycyclic Aromatic Hydrocarbons (PAHs) are formed before they agglomerate to generate particles;  finally, the growth and oxydation of particles control both the mass and the size of soot particles. These mecanisms mainly occur in the post-combustion zone, inside an unsteady turbulent flow of burnt gases. To understand such a problem, the Large Eddy Simulation (LES) approach is well adaped but requires significant modeling efforts. The accurate prediction of both the chemical composition and the burnt gas temperature is particularly crucial to model soot formation. Therefore, it is necessary to account for complex chemistry and heat transfers, including thermal radiation. Moreover, soot particle growth as well as heterogeneous surface chemistry depend on particle size distribution.

A primary approach using semi-empirical soot models and including thermal radiation has shown the faisability of Large Eddy Simulation to simulate soot production. This training is part of the project SMARTLECT supported by the French National Research Agency (ANR) and SAFRAN.

Description / Description

The purpose is to improve the methodology previously proposed to predict soot particle production. Two aspects will be studied. First to improve the chemical description of soot production, two chemistry modelings - a tabulated chemistry and a mixed reduced chemistry/tabulated chemistry - will be compared in a flame configuration for the prediction of soot precursors. Second, the lagrangian solver developped in the LES code AVBP will be used to track soot particles, to account for soot size distribution. Academic configurations such as homogeneous reactors, premixed and non-premixed counterflow flames will be used to test both aspects. The models will be finally applied to an industrial burner.

Here are the main steps of this training:

- Bibliography study on chemistry modeling and soot production calculation using Eulerian or Lagrangian approaches

- Learning the AVBP code and setting-up of the test cases

- Simulations using both chemical models and the Lagrangian approach

- Analysis of results.

Contacts / Contacts

Name: Riber Eleonore
Phone: 05 61 19 31 15
Fax: 05 61 19 30 00
Email: riber@cerfacs.fr

Name: Cuenot Bénédicte
Phone: 05 61 19 30 44
Fax: 05 61 19 30 00
Email: cuenot@cerfacs.fr

Salary / Rémunération

580 Euros/month