This paper describes how active galactic nuclei can heat galaxy-cluster plasmas by driving convection in the intracluster medium. A model is proposed in which a central supermassive black hole accretes intracluster plasma at the Bondi rate ṀBondi and powers a radio source. The central radio source produces cosmic rays, which mix into the thermal plasma. The cosmic-ray luminosity Lcr is ∝ ṀBondi...

The sensitivity of North Atlantic Deep Water formation to variations in mean surface temperature is explored with a meridional-vertical plane ocean model coupled to an energy balance atmosphere. It is found that North Atlantic Deep Water formation is favored by a warm climate, while cold climates are more likely to produce Southern Ocean deep water or deep-decoupling oscillations (when the Sout...

This investigation deals with the combined effects of Navier slip, suction/injection, convective cooling and temperature dependent viscosity on an unsteady third grade fluid flow in a porous channel filled with saturated porous medium. The heat exchange with the ambient at the channel surfaces is assumed to obey Newton’s law of cooling. The model equations governing the flow system are solved u...

Influence of convective cooling at the extrudate’s free surfaces on its own swelling behaviour is examined numerically when viscous fluids of a Newtonian type are extruded. In circular die extrusion, increasing the surface heat transfer coefficient h increases extrudate’s thickness swell at low Nahme-Griffith number Na; at high Na, however, this trend tends to be reversed. With annular dies, a ...

This paper introduces a new global analytical model of the heat dissipation process that occurs in passively-cooled embedded systems, and explicits under what circumstances the folklore assumption that exponential cooling laws apply in such context is valid. Since the power consumption and reliability of microprocessors are highly dependent on temperature, both designers and, later on, run-time...

The simulation of nonlinear ultrasound propagation through tissue realistic media has a wide range of practical applications. However, this is a computationally difficult problem due to the large size of the computational domain compared to the acoustic wavelength. Here, the k-space pseudospectral method is used to reduce the number of grid points required per wavelength for accurate simulation...

Recent observational analysis reveals the central role of three cloud types, congestus, stratiform, and deep-convective cumulus clouds, in the dynamics of large scale convectively coupled Kelvin waves, westward propagating 2-day waves, and the Madden–Julian oscillation. Recently, a systematic model convective parametrization highlighting the dynamic role of the three cloud types has been develo...

We examine the long-standing cooling flow problem in galaxy clusters with 3D MHD simulations of isolated clusters including radiative cooling and anisotropic thermal conduction along magnetic field lines. The central regions of the intracluster medium (ICM) can have cooling timescales of ∼ 200 Myr or shorter—in order to prevent a cooling catastrophe the ICMmust be heated by some mechanism such ...

Buoyancy and velocity scales for dry convection in statistical equilibrium were derived in the early twentieth century by Prandtl, but the scaling of convective velocity and buoyancy, as well as the fractional area coverage of convective clouds, is still unresolved for moist convection. In this paper, high-resolution simulations of an atmosphere in radiative–convective equilibrium are performed...