Experimental Study Of Soot Oxidation Mechanisms By In-Situ Optical Methods Within A Laminar Diffusion Flame: Fuel Effects.

17 May 2023

Job Information

Organisation/Company

Centre National de la Recherche Scientifique - CNRS UMR 6614

Department

Optics and Lasers

Research Field

Physics » Metrology

Researcher Profile

Recognised Researcher (R2)

Country

France

Application Deadline

1 Jun 2023 - 09:00 (Europe/Paris)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

8,75

Offer Starting Date

15 Jun 2023

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Context:

Soot emissions generated during combustion have important consequences on the environment and health and are the subject of concern for the emitting sectors, in particular the sectors linked to human mobility. The aeronautical sector is thus concerned and will be subject to increasingly restrictive standards in the coming years. It should be noted that these emissions are also responsible for the formation of clouds (contrails) which can have a climatic impact.

Soot oxidation is a key process in the removal of these nanoparticles. It is estimated that 90% of soot is oxidized during the combustion process itself (Stanmore, Brilhac et al. 2001). However, this phenomenon, which is still poorly understood, is similar in effectiveness to surface growth, the effect of which is opposite and which makes the balance between the two difficult to model. It is therefore important to better understand the oxidation phenomenon. The latter involves the local temperature, the presence of oxidizing species and the degree of disorder of the carbonaceous nanostructure of the soot (Yehliu, Vander Wal et al. 2012). This results in time-varying reactivity as the nature and composition of the soot changes during its formation (maturity). Finally, the role of oxidizing species appears to differ. In particular, O2 molecules are suspected to penetrate the spherules themselves, producing a kind of "internal combustion", whereas OH would represent a more "surface" aggression. Thus, a better understanding of these modes of oxidation requires a better consideration of the morphology of the particles and in particular the surface/volume ratio (or specific surface) which is almost never considered. Finally, we note an important role played by the fuel (Jeon and Park 2018).

Objective / mission :

The objective of this work is to better understand the oxidation mechanisms of soot particles within flames. This will consist in implementing advanced optical techniques coupling light extinction and spectral scattering (Yon et al. 2021-a & 2021-b) within a two-stage combustion device. Soot particles will be generated within a miniCAST and then injected into the core of an untrimmed lean flame in which the previously injected soot will gradually oxidize. By this approach, we will isolate the oxidation mechanisms, allowing to take into account the evolution of the soot maturity. An adaptation of the miniCAST to generate soot particles from liquid fuels will be carried out in order to study the role played by the fuel. Sustainable aviation fuels (SAF) will be investigated. The soot aerosol injected in the heart of the lean flame will be enriched in O2 in order to identify the role of this molecule in the oxidation process. Finally, synchrotron experiments are envisaged to access information at the scale of the primary spherule (Yon, Ouf et al. 2018). This work will be conducted jointly with CERFACS, which will be able to simulate the experiment in order to improve the oxidation models.

Requirements

Research Field

Physics » Metrology

Education Level

PhD or equivalent

Skills/Qualifications

The PhD must have a PhD thesis and experience in optical aerosol metrology, if possible, for soot particles. Expertise in combustion is welcome. A good knowledge of spoken and written English is mandatory, French is useful.

Specific Requirements

Meetings and progress reports are to be expected with the SAFRAN company. Missions are also required to ensure possible measurements on synchrotron.

Languages

ENGLISH

Level

Excellent

Languages

FRENCH

Level

Basic

Research Field

Physics » Metrology

Years of Research Experience

1 - 4

Internal Application form(s) needed

Subject of the project English.pdf

English

(174.93 KB - PDF)

Download

Sujet Projet Francais.pdf

English

(190.4 KB - PDF)

Download

Additional Information Work Location(s)

Number of offers available

1

Company/Institute

CNRS UMR6614 CORIA

Country

France

City

Saint Etienne du Rouvray

Postal Code

76800

Street

Avenue de l'Université

Geofield

Where to apply

E-mail

[email protected]

Contact

City

Saint Etienne du Rouvray

Website

https:// www. coria.fr

Street

Avenue de l'Université - BP 12

Postal Code

76801

STATUS: EXPIRED