The 32nd meeting of the Sandbox Series will be on:
Stochastic Lagrangian modeling of turbulent flows: accounting for coherent structures and intermittency
The accurate modeling, simulation, and prediction of dispersed turbulent two-phase flows are essential for a wide range of applications. In this context, developing stochastic Lagrangian models for tracking the particle phase is closely associated with advances in reduced PDE models, such as URANS and LES methods. These reduced models, which filter out small motion scales, cannot account for the temporal and spatial correlations inherent to the structured motions present in turbulent flow.
In this talk, I will present two examples of extended stochastic Lagrangian models designed to better incorporate the correlations induced by coherent turbulent structures within these reduced frameworks. The first example focuses on modeling the tumbling motion of non-spherical tracers, using time-inhomogeneous jump-driven stochastic differential equations (SDEs) where jump dynamics account for particle trapping events within vortex structures. The second example addresses the stochastic modeling of Lagrangian dissipation rates, a key element in characterizing intermittency. Here we adopt a Volterra SDE viewpoint and employ a kernel comparison lemma approach to select reasonable (numerically tractable) kernel candidates.
Schedule
1200-1245: Mireille Bossy
1245-1315: Discussion
1315-1330: Break
1330-1345: Mini-talk 1 – Antoine Moneyron (INRIA)
1345-1400: Mini-talk 2 – James Woodfield (ICL)
1400-1430: Discussion & close