The LEGI (Grenoble, France) is seeking a Postdoctoral Research Assistant in two-phase flow sediment transport modelling as part of a one year project funded by the Labex TEC21. The goal of this project is to perform two-phase turbulent resolving simulations (LES) of intense bed-load sediment transport (sheet flow) for which High-Resolution experimental data have been recently obtained at LEGI (Revil-Baudard et al., JFM 2015). The two-phase LES model has been implemented in openFOAM (Cheng and Hsu, 2014) and is currently under validation. During this project, the Double Averaging Methodology (Nikora et al., 2013) will be applied to the LES simulations to provide more insight into the complex couplings between the large-scale turbulent coherent flow structures, the particle and the mobile bed dynamics. The understanding of two specific observations are of particular interest (i) the strong damping of turbulent mixing efficiency associated with a reduction of the von Karman constant by a factor of two, and (ii) the increase of concentration diffusivity associated with a reduced Schmidt number value of about 0.4. The numerical 3D simulations will provide the missing spatial resolution (stream-wise and span-wise directions) of the experimental 1D data to further investigate the mechanisms responsible for these two significant turbulence modifications. In a second step, we also want to investigate the role of particle inertia on these mechanisms by using different sediment types (size and density) for which new experimental data will be acquired in another project. The von Karman reduction in sediment laden flows has been documented many times in the literature but no satisfactory explanation of the underlying physical processes has been given so far.
The successful applicant will be hosted by the laboratory LEGI in the MEIGE team under the supervision of Dr Julien Chauchat and Dr David Hurther. He/shill will be interacting with Dr. Guillaume Balarac (MOST team at LEGI) and Dr Tom Hsu (Center for Applied Coastal Research at the University of Delaware). He/she will have access to the regional (CIMENT) and French national (GENCI/CINES) computational centers.The gross salary will be 2518 euros/months, equivalent to a net salary of 2037 euros/month.
Applicants must have completed a PhD in fluid mechanics and have a strong background in sediment transport, turbulence and/or two-phase flow modelling. An experience in using CFD models and/or matlab/python languages are essential. Good command of the English language (both speaking and writing) is a must, speaking french is not mandatory. The successful candidate must have outstanding achievements in his/her doctoral research and possess independent research abilities.
Interested candidates should send their CV, a cover letter as well as the address of three referees by e-mail to Dr Julien CHAUCHAT (email@example.com).
The current selection aims at building a reserve list for the position, only selected candidates will be contacted further after the passing of the deadline. The deadline for applications is june 30th 2016. The position is available from september 1st 2016 or thereafter. The postdoc can be extended for one or two years based on funding availability.