PhD postion at IFPEN : Up-scaling and averaging of flows in karstic networks

19 Jan 2024
Job Information

Organisation/Company

IFP Energies nouvelles (IFPEN)

Research Field

Environmental science » Water science
Physics » Computational physics
Physics » Statistical physics
Geosciences » Hydrology

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

31 Oct 2024 - 10:02 (Europe/Paris)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

40

Offer Starting Date

1 Nov 2024

Is the job funded through the EU Research Framework Programme?

H2020 / ERC

Reference Number

101071836

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

This project is part of an ERC funded Synergy, one of the laureates of an ERC synergy
grant. The overall goal consists of developing a predictive flow model in an entire karst net- work. It will be necessary to simulate water flows possibly marked with tracer in networks that may be described with millions of nodes. The flows will not necessarily be saturated, and nonlinear flow/Dp relationships between the inlet and outlet of the ducts lead to the resolution of a large system of nonlinear equations. We recall that 30 % of drinkable water flows through karstic aquifers that are very sensitive to global climate change. Ultimately, we will have to focus on large systems of equations of discretized Laplacian type, with a hollow character, and destructured in the majority of cases, since karst networks can be made of large conduits intersecting a large number of other poorly con-nected conduits. The weights related to the edges of the graph correspond to the hydraulic conductivity of the ducts, and are themselves random. It is therefore necessary to solve large linear systems of the Laplacian type, on weighted graphs with complex topology. The PhD student will be interested in the question of up-scaling on a discrete network, allowing to manage in particular the intrinsic hazard of this modeling chain, due to uncertainties on the values of conductivities and volumes of ducts. We will work with fixed network topology by focusing on the averaging on conductivities. The difficulty is to give meaning to homogenization when working in a discrete context where the underlying Euclidean metric is lost, making the notion of change of scale delicate. One idea will be to work on the spectra of Laplacian matrices generalizing the notion of Fourier transform to graphs, a technique very close to convolutional neural networks.

Supervision by a joint team of several physicists and geoscientists belonging to the ERC funded the karst team and work periods in the partners institutions will be organized (Barcelona, Ljubljana, Neûchatel)

Keywords: Karsts, climate change, floodings, drought, quantitative geosciences, statistical physics, percolation, coupling, applied mathematics, programming, numerical simulation

Requirements

Research Field

Geosciences » Hydrology

Education Level

Master Degree or equivalent

Research Field

Physics » Statistical physics

Education Level

Master Degree or equivalent

Research Field

Environmental science » Water science

Education Level

Master Degree or equivalent

Skills/Qualifications

skills in statistical Physics, Applied mathematics, Quantitative geosciences    programming in python, C++, matlab, 

Languages

ENGLISH

Level

Good

Languages

FRENCH

Level

Good

Research Field

Geosciences » HydrologyEnvironmental science » Water sciencePhysics » Statistical physics

Additional Information
Work Location(s)

Number of offers available

1

Company/Institute

ifpen

Country

France

City

rueil Malmaison

Postal Code

92852

Geofield

Where to apply

E-mail

[email protected]

Contact

City

Rueil-Malmaison

Website

http://www.ifpenergiesnouvelles.com/

Street

4 avenue de Bois-Préau

Postal Code

92852

E-Mail

[email protected]

Mobile Phone

33617185989

STATUS: EXPIRED