We consider time-dependent models for rotating accretion flows onto black holes, where a transition takes place from an outer cooling-dominated disc to a radiatively inefficient flow in the inner region. In order to allow for a transition of this type we solve the energy equation, both, for the gas and for the radiation field, including a radiative cooling flux and a turbulent convective heat f...

Contact person: [email protected] INTRODUCTION There has been much recent research interest in microclimate cooling for individuals working in hot climates whilst wearing protective clothing (Bomalaski et al. 1995; Chen et al. 1997; Cheuvront et al. 2003; Chinevere et al. 2008). Attempts have been made to develop cooling garments that augment convective (air cooled garments), conductive...

Using the National Environmental Satellite, Data, and Information Service–Cooperative Institute for Research in the Atmosphere (NESDIS–CIRA) tropical cyclone infrared (IR) imagery archive, combined with best track storm center fix information, a coherent depiction of the temporal and azimuthally averaged spatial structure of hurricane cloudiness is demonstrated. The diurnal oscillation of areal...

Abstract The modern Arctic climate during wintertime is characterized by sea-ice cover, a strong surface temperature inversion, and the absence of convection. Correspondingly, energy balance in atmosphere today dominated atmospheric radiative cooling advective heating, so-called Radiative Advective Equilibrium (RAE). Climate change involves melt, vanishing emergence convective precipitation. He...

Convective heat transfer as an energy transport phenomenon occurs in various engineering and natural systems such exchangers, chemical reactors solar collectors, cooling systems, transportation of contaminant urban landscape air pollution, motion sea or ocean waves others [...]

A 3D computational electromagnetic-thermal coupled analysis was performed to analyze the effects of auxiliary cooling fans, called air-gap fans, on winding cooling in a large-capacity, high-speed induction motor. A novel non-uniform iron loss distribution mapping method considering time and rotation period was introduced to provide more accurate thermal modeling. Winding cooling performance in ...

Water vapor jet assisted metal cutting is a pollution-free green cutting technique. This paper has developed a three-dimensional finite element model of water vapor jet assisted cutting in order to understand the influence of its cooling and lubricating effect on cutting process. The cooling effect of water vapor jet is modeled with a convective heat transfer coefficient. A window with the temp...

It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only fo...

This paper investigates the convective heat and mass transfer in nanofluid flow through a porous media due to a stretching sheet subjected to magnetic field, viscous dissipation, chemical reaction and Soret effects. Two types of nanofluids, namely Cu-water and Ag-water were studied. The governing boundary layer equations are formulated and reduced to a set of ordinary differential equations usi...