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An adjoint-based approach to the optimal control of separated flows

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We consider fluid flows, governed by the Navier-Stokes equations, subject to a steady symmetry-breaking bifurcation and forced by a weak noise acting on a slow timescale. By generalizing the multiple-scale weakly nonlinear expansion technique employed in t ...

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Quantitative convergence rates for scaling limit of SPDEs with transport noise

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We consider on the torus the scaling limit of stochastic 2D (inviscid) fluid dynamics equations with transport noise to deterministic viscous equations. Quantitative estimates on the convergence rates are provided by combining analytic and probabilistic ar ...

Academic Press Inc Elsevier Science2024

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The thesis is dedicated to the study of two main partial differential equations (PDEs) in fluid dynamics: the Navier-Stokes equations, which describe the motion of incompressible fluids, and the transport equation with divergence-free velocity fields, whic ...

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Koopman-based Data-driven Robust Control of Nonlinear Systems Using Integral Quadratic Constraints

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This paper introduces a novel method for data-driven robust control of nonlinear systems based on the Koopman operator, utilizing Integral Quadratic Constraints (IQCs). The Koopman operator theory facilitates the linear representation of nonlinear system d ...

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Instability and trajectories of buoyancy-driven annular disks: A numerical study

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We investigate the stability of the steady vertical path and the emerging trajectories of a buoyancy -driven annular disk as the diameter of its central hole is varied. The steady and axisymmetric wake associated with the steady vertical path of the disk, ...

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Dynamical flow networks serve as macroscopic models for, e.g., transportation networks, queuing networks, and distribution networks. While the flow dynamics in such networks follow the conservation of mass on the links, the outflow from each link is often ...

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Stability of a liquid layer draining around a horizontal cylinder: Interplay of capillary and gravity forces

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Good enough: Intermediate complexity atmospheric models improve the representation of processes affecting seasonal snow

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Exploiting the Signal-Leak Bias in Diffusion Models

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MDPI2024

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EPFL2024