SOTUF - an ERC starting grant at EM2C
SOot in TUrbulent Flames: a new look at soot production processes in turbulent flames leading to novel models for predictive LES
SOTUF is an ERC starting grant (see erc.europa.eu/starting-grants for information on ERC starting grants) dedicated to the study of soot production in turbulent flames combining advanced space- and time-resolved optical diagnostics and high-fidelity numerical simulations. The goal of the present project is to provide new insights on the processes governing soot production in turbulent flames to develop novel Large Eddy Simulation (LES) models, encompassing the state-of-art and allowing reliable predictions of soot in turbulent flames. This is done by considering for the first time TiO2 production as a first simplification to investigate nanoparticles-flame-turbulence interactions. The project is coordinated by CNRS (DR04 Ile-de-France Sud) and lead by the EM2C laboratory. SOTUF started in June 2018 and will run for six years. The Principal Investigator of SOTUF is Dr. Benedetta Franzelli.
Many practical systems emit soot into the atmosphere as a result of incomplete combustion of hydrocarbons. This pollutant emission is characterized by a distribution of solid carbon particles with different sizes and shapes, which have negative effects on human health and environment. Controlling such emission represents a societal issue and an industrial challenge that require a deep understanding of the intricate processes underlying soot production in the turbulent flames that generally characterize practical systems. In this context, progress in numerical simulations is essential to the successful design of low-emission combustion systems.
Unfortunately, the Large-Eddy Simultations (LES) approach, which has successfully demonstrated its capacity to represent gaseous turbulent combustion processes, is far from being predictive for soot emission. Indeed, soot production in turbulent flames is a complex process which is not easy to be represented with the classical LES strategy: the long time scales and the broad range of length scales place soot processes outside the usual scale ranges of LES subgrid models.
In this context, the goal of the present project is to provide new insights on the processes governing soot production in turbulent flames to develop novel LES models, encompassing the state-of-art and allowing reliable predictions of soot in turbulent flames. These objectives will be achieved by:
- Characterizing the turbulence-flame-nanoparticles coupling from novel well-controlled experiments employing advanced space and time resolved optical diagnostics considering both TiO2 and soot nanoparticles.
- Developing new subgrid models based on information extracted from experiments and high-fidelity simulations.
- Validating and applying the developed LES modeling strategy on complex systems.
The research results are expected to drastically improve the prediction of soot and nanoparticles production in industrial configurations, helping to design new low-emission systems with notably reduced soot levels and to optimize the aerosol technology for nanoparticle synthesis.
Main results achieved so far
Since the starting of the project, most of the experimental and numerical tools to perform the characterization and modeling of turbulence-flame-nanoparticles coupling have been developed.
- From the experimental point of view, different configurations with increasing complexity have been implemented. The investigations can today be carried on engineered nanoparticles in suspension or produced in flames: laminar diffusion flames with a pre-vaporized injection of liquid precursors, perfectly-premixed turbulent swirled flames, turbulent spray jet flames. These configurations will be studied to prove the feasibility of using advanced space and time-resolved optical diagnostics from sooting flames to the investigation of spray synthesis of nano-particles and to consequently characterize turbulence-flame-nanoparticles coupling. The available database can be found at: http://em2c.centralesupelec.fr/en/SOTUF_data.
- Concerning simulations, new detailed chemical models for the production of nanoparticles have been developed in a laminar context to be used in high-fidelity simulations of turbulence-flame-nanoparticles interactions. Besides, new approaches have been proposed to validate in a rigorous way the subgrid models expected by the end of the project.
Publications and scientific comunications can be found at: http://em2c.centralesupelec.fr/en/SOTUF_doc.
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