Difficulties and solutions for estimating transport by perturbative experiments

The first part of this work reviews the algebraic matricial approach to transport data inversion. It works for the convection-diffusion transport equation used for periodic signals and provides a formally exact solution, as well as a quantitative assessment of error bars. The standard methods of reconstruction infer the diffusivity D and pinch V by matching experimental data against those simulated by transport codes. These methods do not warrant the validity of either the underlying models of transport, or of the reconstructed D(r) and V(r), even when the results look reasonable.

Hydrodynamical Numerical Simulations of Complex-Shaped Moving Bodies by means of Dynamic Overlapping Grids

In this work the numerical simulations of a submarine in straight ahead motion with the appendages at several prescribed deflection angles are performed. Due to the complex geometry involved (the presence of moving appendages), these simulations are rather demanding form the point of view of both grid generation and accuracy of the numerical method. In order to analyze these aspects, the numerical solutions are computed by means of an unsteady Reynolds averaged Navier-Stokes equations solver, which is particularly effective because of the high order discretization schemes adopted.

On the Aerodynamic Heating of VEGA Launcher: Compressible Chimera Navier-Stokes Simulation with Complex Surfaces

The results of accurate compressible Navier-Stokes simulations of aerodynamic heating of the Vega launcher are presented. Three selected steady conditions of the Vega mission profile are considered: the first corresponding to the altitude of 18 km, the second to 25 km and the last to 33 km. The numerical code is based on the mathematical model described by the Favre-Average-Navier-Stokes equations; the turbulent model chosen for closure is the one-equation model by Spalart-Allmaras.

How can macroscopic models reveal self-organization in traffic flow?

In this paper we propose a new modeling tech- nique for vehicular traffic flow, designed for capturing at a macroscopic level some effects, due to the microscopic granularity of the flow of cars, which would be lost with a purely continuous approach. The starting point is a multiscale method for pedestrian modeling, recently introduced in [1], in which measure-theoretic tools are used to manage the microscopic and the macroscopic scales under a unique framework.

Variable Annuities and embedded options: some remarks in a fuzzy logic framework

Variable annuities are investment products offered by Insurance Companies. They allow investors to place assets in mutual funds under the umbrella of a tax-deferred account. The account value of variable annuities fluctuates based on the performance of the selected mutual funds and therefore some risks are involved. Recently there has been a growing interest in using fuzzy numbers to deal with financial uncertainty.