Asynchronous methods for combustion and atmospheric plasmas – MACOPA
The MACOPA project focuses on developing a generic software toolbox for the simulation of multi-scale multi-physics transport problems. These problems typically deal with very stiff and localized source terms. Indeed many natural of industrial phenomena exhibit this behaviour. Large-scale effects are generally triggered at much lower scales. In the scope of this project two subjects have been selected: combustion and cold atmospheric plasma.
The numerical schemes, which are generally used for modeling of such problems, usually rely on either explicit or implicit time integration. If explicit time integration is used, the time step is imposed by the most demanding CFL condition over the whole computation domain, which is to say that all cells are advanced at the rate of the slowest. For a strongly multi-scale problem the required CPU load can become prohibitive. Implicit time integration can overcome the time step restriction but by doing this the high frequencies are damped out. This approach is not suitable for strongly coupled problems. If for instance one wants to study combustion instabilities, it is irrelevant to use implicit integration time steps much bigger than the stability condition otherwise the mechanism leading to the instabilities would be totally damped out. Asynchronous time integration schemes have been developed at the LAPLACE Laboratory and at ONERA for the past few years. The schemes use local time stepping in each cell consistently in time. Besides asynchronous time integration can easily be coupled with adaptive meshing (Asynchronous Adaptive Mesh Refinement) in order to also adapt spatially to the stiff phenomena. Both techniques have been successfully used to simulate non-equilibrium discharges used for flow control.
Combustion problems have much in common with discharge problems, steep gradients, strong locality, stiffness of the source terms, demanding time constrain. That is why asynchronous time integration can do a great job also for combustion modeling. In the near future the MACOPA software toolbox is intended to treat multi-physics problem such as plasma-enhanced combustion and microwave plasma generation and sustention. To achieve this goal, a collaborative work has been started in 2010 between IMFT and LAPLACE (a one year post-doc fellowship has been awarded by the Midi-Pyrénées Region).
This project is perfectly in the scope of the number one theme of this call, which is modeling and simulation of complex systems. The MACOPA software toolbox will be based on an on-the-shelf asynchronous integration core developed in previous collaboration between ONERA, LAPLACE and IMFT. The research effort will be directed towards to goals :
1. Physics oriented modules: a combustion module developed by IMFT and a plasma module developed by LAPLACE
2. Enhancement of the asynchronous core towards High Performance Computing : developing accurate high-order methods (ONERA) and parallelization of the asynchronous algorithm (IRIT)
Monsieur Laurent SELLE (INSTITUT NATIONAL POLYTECHNIQUE DE TOULOUSE) – firstname.lastname@example.org
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
IRIT INSTITUT NATIONAL POLYTECHNIQUE DE TOULOUSE
IMFT INSTITUT NATIONAL POLYTECHNIQUE DE TOULOUSE
ONERA ONERA - CENTRE D'ETUDES ET DE RECHERCHES DE TOULOUSE
LAPLACE UNIVERSITE TOULOUSE III [PAUL SABATIER]
Help of the ANR 358,998 euros
Beginning and duration of the scientific project: February 2012 - 36 Months