« Hydrodynamics and solute transport in the presence of semi-permeable walls in a Taylor-Couette cell » - Two-year Post-Doctoral position in experimental and numerical fluid dynamics

 Membrane separation techniques, used to separate the constituents of a mixture by driving it through a semi-permeable membrane, are ubiquitous in industry (wastewater treatment), medical sciences (dialysis) or environmental issues (desalination). They suffer from the accumulation of the retained materials near or inside the membrane, which deteriorates their performances, due to various mechanisms such as adsorption, scaling, osmotic pressure or the buildup of a gel layer. These mechanisms remain poorly understood, as they are numerically difficult to model and occur near opaque membranes hindering optical measurement techniques. These mechanisms also impact the hydrodynamics at stake in the separation devices. Reciprocally, these mechanisms can also be used to act upon and abate accumulation, by promoting hydrodynamic instabilities for instance.

This Post-Doc position endeavors to address these phenomena in a Taylor-Couette cell, where brine is driven in the gap between a semi-permeable rotating inner cylinder and a clear impermeable fixed outer cylinder. A two-pronged approach will be adopted over the 24 months of the contract. First, building on previous work performed at M2P2, direct numerical simulations by spectral methods and stability analyses will be developed, to address in this configuration the dynamics of centrifugal instabilities and solute accumulation, coupled by osmotic pressure. Then, an experimental rig must be designed and built with the help of IRPHE’s team. Beyond the coupling by osmotic pressure, its use should also be extended to cope with other mechanisms related to solute accumulation such as mineral scaling. Measurements of the velocity field will be performed by PIV, and various techniques will be assessed to study the salt concentration field. 

Financial support (2 years) is not fully secured yet; but it is highly probable for any good candidate (3 awarded fellowships for 7 pre-selected projects). Final decision will be made immediately after a remote presentation on July 4th. Expected start is fall 2023. 

The basic expected qualification is a Ph.D in experimental and/or numerical fluid mechanics. For application, please send a CV and motivation letter to denis.martinand@univ-amu.fr and michael.le-bars@univ-amu.fr asap, and in any case before June 27.