Articolo in rivista

Intermittency in the relative separations of tracers and of heavy particles in turbulent flows

Results from direct numerical simulations (DNS) of particle relative dispersion in three-dimensional homogeneous and isotropic turbulence at Reynolds number Re?~300 are presented. We study point-like passive tracers and heavy particles, at Stokes number St=0.6,1 and 5. Particles are emitted from…

Quantifying trace gas emissions from composite landscapes: A mass-budget approach with aircraft measurements

Quantifying trace gas emissions and the influence of surface exchange processes on the atmosphere is a necessary step towards the control of global greenhouse gas emissions and reliability of air quality models. This paper proposes a procedure based on the mass balance method and implemented on…

An all-densities pedestrian simulator based on a dynamic evaluation of the interpersonal distances

In this paper we deal with pedestrian modeling, aiming at simulating crowd behavior in normal and emergency scenarios, including highly congested mass events. We are specifically concerned with a new agent-based, continuous-in-space, discrete-in-time, nondifferential model, where pedestrians have…

A modular variable Orlicz inequality for the local maximal operator

In this note we prove a modular variable Orlicz inequality for the local maximal operator. This result generalizes several Orlicz and variable exponent modular inequalities that have appeared previously in the literature.

Exponential Lawson integration for nearly Hamiltonian systems arising in optimal control

We are concerned with the discretization of optimal control problems when a Runge-Kutta scheme is selected for the related Hamiltonian system. It is known that Lagrangian's first order conditions on the discrete model, require a symplectic partitioned Runge-Kutta scheme for state-costate equations…

Rayleigh-Taylor turbulence with singular nonuniform initial conditions

We perform direct numerical simulations of three-dimensional Rayleigh-Taylor turbulence with a nonuniform singular initial temperature background. In such conditions, the mixing layer evolves under the driving of a varying effective At wood number; the long-time growth is still self-similar, but no…

Endothelial shear stress hemodynamic simulation

Evidences of Bolgiano-Obhukhov scaling in three dimensional Rayleigh-Binard convection

Regularized lattice Boltzmann multicomponent models for low capillary and Reynolds microfluidics flows

We present a regularized version of the color gradient lattice Boltzmann (LB) scheme for the simulation of droplet formation in microfluidic devices of experimental relevance. The regularized version is shown to provide computationally efficient access to capillary number regimes relevant to…

Numerical simulation of interference effects for a high-speed catamaran

The simulations of the flow around a high-speed vessel in both catamaran and monohull configurations are carried out by the numerical solution of the Reynold averaged Navier–Stokes (RANS) equations. The goal of the analysis is the investigation of the interference phenomena between the two hulls,…