PhD position: Dynamics of flexible fibres in a turbulent channel flow

This project deals with the suspension of flexible fibers in turbulent flows, addressing situations such as the transport of plastic debris or organic matter in oceans and rivers. Modelling the dynamics of these deformable particles within such environmental flows remains a significant challenge, particularly near boundaries. Indeed, the presence of a wall introduces inhomogeneities and anisotropies, drastically complicating the analysis of transport properties. Until now, research on the fiber dynamics in wall-bounded flow has predominantly focused on rigid particles, while investigations into flexible fibers were largely confined to the idealized and simpler framework of homogeneous isotropic turbulence. This PhD project aims to bridge this gap by exploring the dynamics of flexible fibers in wall-bounded flow, specifically within a turbulent channel. 
The proposed research will primarily entail experimental work but will also include a complementary numerical component. It aims to characterize and understand fiber dynamics as a function of the distance from the wall and the flexibility of the particles. Experiments will be conducted in a channel flow, utilizing fibers with varying properties. Measurements of fiber orientation and deformation will be performed using several high-speed cameras and 3D reconstruction algorithms. Subsequently, experimental results will be quantitatively compared to the results of direct numerical simulations conducted within the team.