Ricerc@Sapienza

Superhydrophobic surface features could be used to obtain significant drag reduction in turbulent confined flows (Min and Kim, Phys Fluids 16(7) L55, 2004) [1], (Fukagata et al., Phys Fluids 18, 051703 2006) [2], (Aljallis et al., Phys Fluid 25, 025103, 2013) [3].

The magnetohydrodynamic flow and heat transfer of a liquid metal in a channel past a circular cylinder with walls of non-uniform conductivity were investigated. The applied magnetic field was transversal to the forced flow (x-direction) and coplanar with the obstacle, featuring non-null components in both the z- and y-directions. Moreover, the cylinder was displaced by the duct centreline toward the bottom wall and its surface was at uniform temperature, so that a ΔT was present between the obstacle and the fluid at the inlet.

A two-phase model based on the double-diffusive approach is used to perform a numerical study on natural convection from a pair of differentially heated cylinders aligned side by side in a nanofluid-filled inclined square enclosure, assuming that Brownian diffusion and thermophoresis are the only slip mechanisms by which the solid phase can develop a significant relative velocity with respect to the liquid phase.

Natural convection in water-filled square cavities inclined with respect to gravity, having one wall
cooled at 0°C and the opposite wall heated at a temperature ranging between 4°C and 30°C, is studied
numerically for cavity widths spanning from 0.02 m to 0.1 m in the hypothesis of temperaturedependent
physical properties, with the main aim to determine the optimal tilting angle for maximum
heat transfer. A computational code based on the SIMPLE-C algorithm is used to solve the system of

Some considerations to preliminarily design the size of the Expansion Volume (EV) and the relief pipes for a Vacuum Vessel Pressure Suppression System, to be adopted in a fusion reactor based on a helium cooled blanket, are presented. The volume of the EV depends on the total energy of the cooling system and it can be sized based on a required final pressure at equilibrium, by a simple energy balance. Two different EV solutions have been analysed: a “dry” EV and a “wet” EV.

The Centralized Radio Access Network (C-RAN) provides a valid solution to overcome the problem of traditional RAN in scaling up to the needed processing resource and quality expected in 5G. The Common Public Rate Interface has been defined to transport traffic flows in C-RAN and recently some market solutions are available. Its disadvantage is to increase by at least 10 times the needed bandwidth and for this reason its introduction will be gradual and will coexist with traditional RAN solutions in which Ethernet traffic is carried towards the radio base stations.

A dam-break flood model based on a contravariant integral form of the shallow water equations is presented. The numerical integration of the equations of motion is carried out by means of a finite volumefinite difference numerical scheme that involves an exact Riemann solver and which is based on a high-order WENO reconstruction procedure. An original scheme for the simulation of the wet front progress on the dry bed is adopted. The proposed model capacity to correctly simulate the wet front progress velocity is tested by numerically reproducing the dry bed dam-break problem.