Deadline for registration: 15 days before the starting date of each training
Duration : 5 days / (35 hours)
This training session allows participants to understand the underlying basics of Large Eddy Simulation (LES): numerics, boundary conditions, LES closures and combustion modeling. The CFD code AVBP (version 6.2) co-developed by CERFACS and IFPEN is used for hands-on to compute both academic and realistic configurations of reacting compressible flows.
This training session is for engineers, physicists, computer scientists and numerical analysts who wish to learn to useLES and to manipulate a CFD code dedicated to LES.
Unix, Fortran, numerical simulation.
Scientific contact : Eleonore RIBER
- Trainees/PhDs/PostDocs : 250 €
- CERFACS shareholders/CNRS/INRIA : 750 €
- Public : 1500 €
(Every day from 9h to 17h30)
Day 1 – Introduction
9h00 Welcome and coffee
9h45 LES of reacting compressible flows – Introduction
The differences between RANS and LES.
The codes for LES.
10h45 How does AVBP work
Files – scripts – general organization.
11h30 Installation on computers – accounts – computer organization
14h00 How does HIP work – Description of HDF format
14h30 Hands-on work on computers: examples of LES post-processing
Non-reacting and reacting (stabilised flames and ignition) cases.
Run temporal post-processing, snapshots (using Paraview), unsteady diagnostics, etc.
Day 2 – Numerical Schemes
9h00 Dissipation and dispersion of waves
Introduction using a simple second order scheme. Impact of scheme order on result accuracy. Scheems required for LES.
9h45 Implementation of numerical schemes in a LES code
10h30 Hands-on: measurement of dispersion and dissipation on acoustic wave propagation
14h00 Hands-on: simulation of two-dimensional vortices
Effects of mesh and scheme.
Day 3 – Boundary conditions
9h00 Boundary conditions in compressible flows: characteristic method
9h45 Implementation of boundary conditions in a LES code
10h30 Hands-on: simulation of one-dimensional acoustic waves reaching non-reflecting boundaries
Generation of propagating acoustic waves.
14h00 Hands-on: manipulation of boundary conditions to mimic reflexions or to produce non-reflecting conditions
Applications to vortices going through outlet.
Day 4 – Combustion
9h00 LES of reacting flows: thermodynamics, kinetics, laminar flames and turbulent combustion model
10h30 Hands-on: simulation of one-dimensional laminar flame with and without flame thickening
14h00 Hands-on: simulation of a forced two-dimensional laminar flame
Day 5 – Morning – Subgrid scale and wall modelling
9h00 Closure models for LES and wall modelling
10h30 Hands-on: post-processing LES of turbulent pipe flow.
Effect of subgrid scale model, wall model and grid refinement.
Day 5 – Afternoon – Turbulent flames using C3S
14h00 Hands-on: setting up a complete run for a turbulent reacting configuration (EKT) using the C3S GUI.
Starting from an existing mesh (Centaur) and an initial zero velocity field, setting of boundary conditions and checking of the beginning of the filling phase.
Ignition of the EKT configuration starting from a stabilized non-reacting flow.
Analysis of the stabilised reacting flow.