진학프로석·박사 채용 접수 플랫폼

Temperature and species measurements for the development of low NOx plasma-assisted combustion systems 

Context:

New energy technologies must answer the challenge of reducing CO2 and NOx emissions in hydrocarbon combustion, which represents more than 80% of primary energy consumption worldwide. The GreenBlue program (Greenhouse gas and pollutant emissions reduction using plasma-assisted combustion for a Blue planet) is new 5-year program started in November 2021 at EM2C to develop carbon-free and carbon-neutral solutions using hydrogen or sustainable alternative fuels, with low NOx emissions. 

EM2C has a leading expertise in plasma-assisted combustion [1,2] and operates several experimental facilities (10 to 300 kW) specifically dedicated to this program [3–6]. Experimental and numerical work will be conducted to address with three major questions:

• understand the fundamental physical phenomena enhancing combustion and reducing NOx with an original method based on Nanosecond Repetitively Pulsed (NRP) discharges [3–5]. The NRP approach consists in stabilizing flames with high voltage pulses of 10 ns duration applied at 10-100 kHz. 
• validate and apply the acquired knowledge in medium to large-scale combustion chambers. 
• Develop numerical models to simulate plasma-assisted combustion in high power rigs representative of industrial applications.

Postdoctoral project:

This project aims to improve our understanding of NOx formation mechanisms and thermochemical effects in Plasma Assisted Combustion. This will be achieved by measuring simultaneously the rates of dissociative quenching reactions of N2, responsible for NO formation and the associated degree of ultrafast heating [6,7]. To do this, gas temperature and composition measurements will be performed in nanosecond repetitively pulsed (NRP) discharges initiated in heated air at temperatures of interest for combustion (1000-2000 K) as well as in other combustion mixtures.

This project will focus on performing TALIF techniques to measure the densities of atomic nitrogen, atomic oxygen and nitric oxide. The candidate will also continue ongoing work on hybrid fs-ps CARS gas temperature measurements targeting the electronic ground state of molecular nitrogen.

The final goal of the project will be to compare the combined measurements of temperature and chemical composition with numerical predictions. 

Profile of the candidate:

The postdoctoral candidate must have a background in optical diagnostics and experimental research. Preference is given to those candidates with an additional background in plasma physics. The position is open for a duration of 1 year, extendable to 2 years.

Contact: Sean McGuire, Maître de Conférences at CentraleSupélec, sean.mc-guire@centralesupelec.fr

 Christophe Laux, Professor at CentraleSupélec, christophe.laux@centralesupelec.fr

[1] A. Starikovskiy, N. Aleksandrov, Plasma-assisted ignition and combustion, Progress in Energy and Combustion Science 39 (2013) 61–110. https://doi.org/10.1016/j.pecs.2012.05.003.

[2] Y. Ju, W. Sun, Plasma assisted combustion: Dynamics and chemistry, PROG. ENERGY COMBUST. SCI. 48 (2015) 21–83. https://doi.org/10.1016/j.pecs.2014.12.002.

[3] S. Barbosa, G. Pilla, D.A. Lacoste, P. Scouflaire, S. Ducruix, C.O. Laux, D. Veynante, Influence of nanosecond repetitively pulsed discharges on the stability of a swirled propane/air burner representative of an aeronautical combustor, Philos Trans A Math Phys Eng Sci 373 (2015) 20140335. https://doi.org/10.1098/rsta.2014.0335.

[4] G. Vignat, N. Minesi, P.R. Soundararajan, D. Durox, A. Renaud, V. Blanchard, C.O. Laux, S. Candel, Improvement of lean blow out performance of spray and premixed swirled flames using nanosecond repetitively pulsed discharges, Proceedings of the Combustion Institute 38 (2021) 6559–6566. https://doi.org/10.1016/j.proci.2020.06.136.

[5] G. Pilla, D. Galley, D.A. Lacoste, F. Lacas, D. Veynante, C.O. Laux, Stabilization of a turbulent premixed flame using a nanosecond repetitively pulsed plasma, IEEE Transactions on Plasma Science 34 (2006) 2471–2477. https://doi.org/10.1109/TPS.2006.886081.

[6] D.L. Rusterholtz, D.A. Lacoste, G.D. Stancu, D.Z. Pai, C.O. Laux, Ultrafast heating and oxygen dissociation in atmospheric pressure air by nanosecond repetitively pulsed discharges, J. Phys. D: Appl. Phys. 46 (2013) 464010. https://doi.org/10.1088/0022-3727/46/46/464010.

[7] N.A. Popov, Erratum: Kinetics of plasma-assisted combustion: effect of non-equilibrium excitation on the ignition and oxidation of combustible mixtures, Plasma Sources Sci. Technol. 25 (2016) 049601. https://doi.org/10.1088/0963-0252/25/4/049601.