Latest reviews of technological issues that still prohibit long term travel into

space, such as the Mission to Mars, clearly identify spacecraft fire safety as a crucial

domain that requires more fundamental insights. For several decades, many sound

scientific works on fire growth and the movement of smoke and heat have been

providing the engineers with the information and tools that are necessary in the

design of fire detection and the definition of the subsequent procedures on ground.

However, due to the specific conditions encountered in spacecraft, the tools for

normal gravity fire detection design needs to be assessed into realistic space

conditions and modified according to the discrepancies among detection thresholds in 1g and 0g, that could lead to unappropriate procedures, then disasters, following a

misdetection -or a non-detection- in microgravity.

Along the Ph.D., the student will join an experimental team at ∂'Alembert

Inst. to investigate flame spread over small samples in microgravity. The

experiments will take place onboard the Novespace zeroG airplane.

Since 2014, the experimental rig DIAMONDS (Detection of Ignition And Mitigation Onboard for Non-Damaged Spacecraft) developped at Sorbonne Université [1] has allowed for these experiments. Recent Ph.D. works by Y. Li [2] have paid a specific

attention to the influence of the ambient atmosphere conditions (chemical

composition, flow, pressure). These conditions especially deliver means of soot

production characterization and control. Soot has been shown to play a key role into the radiative heat transfer which significantly contributes to fire hazards in the absence of buoyancy. Following these findings, the student will especially focus on setting and assessing state-of-the-art fire detection systems. The ambition of the Ph.D. works will then be to investigate alternative fire mitigation strategies that could contribute to enhance spacecraft fire safety procedures. To this end, J.-M. Citerne (Sorbonne Univ.) designed a demonstrator, called UNBURNIT (UNconventional BUrning Responses to Non-Invasive Techniques, that enables acoustic and/or electric perturbations. Since 2023, UNBURNIT has flown onboard the zeroG airplane, proving that these perturbations may lead to the extinction of a flame that readily spreads in the absence of any of these perturbations.

The works will be complemented by numerical studies to further assess the

experimental analysis. To do so, the student will collaborate with Jean-Louis

Consalvi (IUSTI, Marseille, France) and his co-workers. The numerical code that

they developed is properly designed to model soot production and radiative heat

transfer in non-buoyant laminar diffusion flames. As a result, the proper numerical

simulation of the flame signature detection is expected to be also a potential output of

the Ph.D. works.

This Ph.D. is expected to contribute to ongoing international projects, such as

SpAcecraFt Fire Safety Demonstration (SAFFIRE) and Flammability Limits At

REduced gravity, lead by NASA and JAXA, respectively.

[1] http://www.dalembert.upmc.fr/home/legros/index.php/publications

[2] Y. Li, Flame and smoke characterization in reduced gravity for enhanced spacecraft safety, Thèse de Doctorat soutenue le 6 Décembre 2022, Sorbonne Université

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For more Information about the topics and the co-financial partner (found by the lab !); contact Directeur de thèse - guillaume.legros@sorbonne-universite.fr

Then, prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online  before March 14th, 2025 Midnight Paris time !