Description du sujet de thèse

Dynamics of Pulsatile Flows in Geometrically Complex Systems

Contexte de travail

Physiological pulsatile flows are unsteady and can exhibit hydrodynamic instabilities; in large blood vessels, turbulence may even arise. Such unsteady flow conditions and the resulting fluctuations in wall shear stress are known to promote endothelial dysfunction—the impairment of the inner lining of blood vessels— which plays a central role in the development of vascular diseases. Blood vessels further complicate this picture through their complex geometries, featuring diameter variations, curvature, and bifurcations that can profoundly influence flow stability. Yet, even in the simplified setting of pulsatile flow through a straight pipe, the underlying instability mechanisms and routes to turbulence remain poorly understood.

The funded PhD project will focus on understanding how pulsatile forcing and geometrical perturbations (e.g. curvature and branching) influence flow stability, transition to turbulence, and wall shear stress, with direct relevance to cardiovascular flows. The research work will be primarily experimental and will involve laboratory studies of pulsatile pipe flows in straight, curved, and branched geometries. Advanced flow diagnostics will be employed, including planar and stereo particle image velocimetry (PIV) to resolve time resolved velocity fields, as well as pressure based measurements to quantify frictional drag and wall shear stress. The project offers hands-on experience with state-of-the-art experimental facilities and provides training in data analysis, instability characterization, and fluid mechanical interpretation, with direct relevance to both fundamental fluid mechanics and flow applications.

The student will integrate to the Rheology of concentrated suspensions re-search group of the Physics Institute of Nice (INPHYNI), where a pulsatile pipe flow has recently been built. She or He will further benefit from close interactions with research groups working on numerical and theoretical aspects of turbulence, at INPHYNI and in other laboratories of Université Côte d'Azur.

The PhD candidate should have a strong background in physics, with advanced knowledge of fluid mechanics and out-of-equilibrium physics. A strong interest in developing and conducting experiments, as well as in experimental or numerical data processing and analysis, is essential.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.