Disperse Two-Phase Flows, with Applications to Geophysical Problems

Weakly Inhomogeneous Turbulence Theory with Applications to Geophysical Flows

In this study, we investigate the problems of inhomogeneous turbulence. The main goal has been to find the connections between analytic turbulence theories, notably the formalism of the direct interaction approximation (DIA), and turbulence phenomenology. To simplify the results from an inhomogeneous DIA model, we have employed a diagonalization procedure and an assumption of weak inhomogeneity...

Asymptotic - Preserving schemes for kinetic – fluid modeling of disperse two - phase flows with variable fluid density ∗

We are concerned with a coupled system describing the interaction between suspended particles and a dense fluid. The particles are modeled by a kinetic equation of Vlasov-Fokker-Planck type, and the fluid is described by the incompressible Navier-Stokes system, with variable density. The systems are coupled through drag forces. High friction regimes lead to a purely hydrodynamic description of ...

Asymptotic-preserving schemes for kinetic-fluid modeling of disperse two-phase flows

We consider a system coupling the incompressible Navier–Stokes equations to the Vlasov– Fokker–Planck equation. Such a problem arises in the description of particulate flows. We design a numerical scheme to simulate the behavior of the system. This scheme is asymptotic-preserving, thus efficient in both the kinetic and hydrodynamic regimes. It has a numerical stability condition controlled by t...

Second-order scheme for quadrature-based velocity high order moment methods for disperse two-phase flows

Solvable phase diagrams and ensemble inequivalence for two-dimensional and geophysical turbulent flows

Using explicit analytical computations, generic occurrence of inequivalence between two or more statistical ensembles is obtained for a large class of equilibrium states of two-dimensional and geophysical turbulent flows. The occurrence of statistical ensemble inequivalence is shown to be related to previously observed phase transitions in the equilibrium flow topology. We find in these turbule...