The energy released in solar flares derives from a reconfiguration of magnetic fields to a lower energy state, and is manifested in several forms, including bulk kinetic energy of the coronal mass ejection, acceleration of electrons and ions, and enhanced thermal energy that is ultimately radiated away across the electromagnetic spectrum from optical to x rays. Using an unprecedented set of coo...

An important question that must be addressed by any energy harvesting technology is related to the type of energy available (Paradiso et al., 2005; Roundy et al., 2003). Among the renewable energy sources, kinetic energy is undoubtedly the most widely studied for applications to the micro-energy generation1. Kinetic energy harvesting requires a transduction mechanism to generate electrical ener...

The paper shows the results of the convective heat transfer prediction in turbulent axisymmetric jets impinging onto a flat plate using the newest version (2006) of the k-ω turbulence model of Wilcox [1]. Improvements to the heat transfer predictions are obtained in the strongly strained flow regions with the impingement invariant proposed by Manceau [2] together with the F1 function proposed b...

In free-surface flows, some flow instabilities may be observed, for example in pooled stepped spillways and hydraulic jumps. These instabilities may include some pulsations and oscillations. Most traditional two-phase flow analyses would yield some air-water turbulent flow results combining the contributions of the slow fluctuations and of the turbulent motion. Herein a new turbulence decomposi...

1 Abstract In this paper we discuss the dynamical features of intermittent fluctuations in homogeneous shear flow turbulence. In this flow the energy cascade is strongly modified by the production of turbulent kinetic energy related to the presence of vortical structures induced by the shear. By using direct numerical simulations, we show that the refined Kolmogorov similarity is broken and a n...

A new mechanism of generation of large-scale magnetic fields in colliding protogalactic clouds and merging protostellar clouds is discussed. Interaction of the colliding clouds produces large-scale shear motions which are superimposed on small-scale turbulence. Generation of the large-scale magnetic field is due to a ”shear-current” effect (or ”vorticity-current” effect), and the mean vorticity...

The analysis of impeller shape performance was carried out with the SST (Shear-Stress Transport) model coupled with the streamline curvature turbulence model. This model combines the advantages from the κ−ε and κ−ω models, ensuring proper relation between turbulent stress and turbulent kinetic energy and allowing accurate and robust prediction of the impeller blade flow separation. The Multiple...

MRI is a well known and widely spread technique to characterize cardiac pathologies due to its high spatial resolution, its accessibility and its adjustable contrast among soft tissues. In an attempt to close the gap between blood flow, myocardial movement and the cardiac function, researching in the MRI field addresses the quantification of some of the most relevant blood and myocardial parame...

The behaviour of the steady, horizontally homogeneous, neutral, barotropic planetary boundary layer (PBL) has recently been examined by Garratt and Hess. In Garratt and Hess (2002) modelled profiles of the mean wind, the geostrophic departure and turbulent stress components were compared with observations; in Hess and Garratt (2002 a,b) predicted integral measures, such as the geostrophic drag ...