Team seminar in 2023

When: Tuesday, December 5^th 2023 at 14:00 (CET)
Where: Coriolis (Galois building)
Speaker: Chiara Calascibetta (University of Rome, Italy)
Topic: Data-driven and equation-informed optimal control of Lagrangian pairs in turbulent flows

When: Monday, September 11^th 2023 at 14:00 (CET)
Where: Coriolis (Galois building)
Speaker: Luca Moriconi (Universidade Federal do Rio de Janeiro, Brazil)
Topic: Stochastic model for coherent state transitions in turbulent pipe flows

When: Thursday, June 1^st 2023 at 10:00 (CET)
Where: Coriolis (Galois building)
Speaker: Josh Williams (STFC, UKRI)
Topic: Modelling aerosol transport in turbulent flows for respiratory diseases
Abstract: I will present an overview of our work in modelling aerosol drug delivery to the respiratory system. To study aerosol particle dynamics in these flows, the Eulerian-Lagrangian approach is applied where the large-scale fluid motion is solved with the volume-filtered Navier-Stokes equations. Due to the particles’ low inertia, their motion will also be influenced by small-scale ‘subgrid’ motions, which motivates the use of a stochastic model for the fluid velocity seen by a particle. I will present our data-driven modelling framework, where we aimed to infer unknown drift and diffusion terms in the stochastic model based on filtered particle-laden direct numerical simulation data.

When: Friday, March 3^rd 2023 at 10:00 (CET)
Where: Coriolis (Galois building)
Speaker: Ciro Campolina (Team Calisto)
Topic: Fluid flows and boundaries on logarithmic lattices
Abstract: We propose a mathematical framework for the fluid dynamics equations on lattices of logarithmically distributed nodes in Fourier space. Important open problems can be studied in this setting. In this talk, we address the longstanding blowup problem in the 3D incompressible Euler equations and the vanishing viscosity limit of the 2D incompressible Navier-Stokes equations in the presence of solid boundaries. This is a joint work with Alexei Mailybaev.

When: Thursday, February 9^th 2023 at 10:00 (CET)
Where: Coriolis (Galois building)
Speaker: Bernhard Vowinckel (TU Braunschweig, Germany)
Topic: Small-scale sediment transport processes: particle-resolved simulations
Abstract: In this work, I will present results of sediment transport simulations dealing with two prototype scenarios: (1) flocculation of cohesive sediment and (2) rheology of non-cohesive sediment beds. The results are obtained by means of particle-resolved direct numerical simulations and I will show, how one can describe key physical properties fof the suspensions using these sophisticated tools.

When: Thursday, January 26^th 2023 at 13:30 (CET)
Where: Euler Violet (Euler building)
Speaker: Aurore Loisy (IRPHE, Marseille, France)
Topic: Cognitive strategies for olfactory search in turbulence
Abstract: How to track down a source of odor when there is no track to follow? Many insects, such as mosquitoes, are capable of reaching a source of odor from dozens of meters away. While terrestrial animals can follow odor trails on the ground, such trails do not exist in the air: any smooth aerial trail is rapidly destroyed by turbulence. As a result, insects have to navigate an odor landscape made of few randomly scattered patches of odor. Any gradient-based strategy, such as chemotaxis, is doomed to fail and one must rely on cognitive strategies: strategies that rely on memory, abstract representations, and anticipation. In this talk we will show how theoretical and practical tools from artificial intelligence can help us approach and solve this problem. We will also briefly introduce recent results on the strategy for planktonic navigation.

When: Thursday, January 12^th 2023 at 10:00 (CET)
Where: Coriolis (Galois building)
Speaker: Michel Orsi (InPhyNi, Nice, France)
Topic: Simulation of concentrated non-Brownian frictional and adhesive suspensions in linear and nonlinear flows
Abstract: I present a particle-scale simulation method for non-Brownian suspension flows at low Reynolds number, based on the Fictitious Domain Method and supplemented by lubrication corrections. After detailing the implementation of the numerical method in OpenFOAM and the development of frame-invariant sub-grid corrections, I study the role of adhesive forces in frictional suspensions, by varying both intensity of adhesion and volume fraction. In particular, I show that the relative viscosity of the suspension is a function of both volume fraction and shear stress. Then, I investigate the shear-induced particle migration in a pressure-driven channel suspension flow, in which the velocity profile is highly nonlinear. Finally, I compare the results to a modified version of the Suspension Balance Model.