The observable properties of a Type Ia supernova are sensitive to how the nuclear runaway ignites in a Chandrasekhar mass white dwarf at a single point at its center, off-center, or at multiple points and times. We present a simple analytic model for the runaway based upon a combination of stellar mixing-length theory and recent advances in understanding RayleighBenard convection. The convectiv...

The transition to turbulence in pipe flow does not follow the scenario familiar from RayleighBenard or Taylor-Couette flow since the laminar profile is stable against infinitesimal perturbations for all Reynolds numbers. Moreover, even when the flow speed is high enough and the perturbation sufficiently strong such that turbulent flow is established, it can return to the laminar state without a...

the fluid flow and heat transfer in lid-driven enclosures filled with cu-water nanofluid is numerically investigated. the moving vertical walls of the enclosure  are maintained in a constant temperature, while the horizontal walls are insulated. the hybrid scheme is used to discretize the convection terms and simpler algorithm is adopted to couple the velocity field and pressure in the momentum...

Mixed convection of Cu-Water nanofluid is studied numerically in a shallow inclined enclosure by applying lattice Boltzmann method. The D2Q9 lattice and internal energy distribution function based on the BGK collision operator are used in order to develop the thermal flow field. The enclosure's hot lid has the constant velocity of U0 while its cold lower wall has no motion. Moreover, sidewalls ...

The fluid flow and heat transfer in lid-driven enclosures filled with Cu-water nanofluid is numerically investigated. The moving vertical walls of the enclosure  are maintained in a constant temperature, while the horizontal walls are insulated. The hybrid scheme is used to discretize the convection terms and SIMPLER algorithm is adopted to couple the velocity field and pressure in the momentum...

In this paper we review main results of Raleigh Bénard convection. Keywords—Convection, Turbulence Thermal convection is present everywhere. We find it in heating sauce pans, boilers, furnaces, and in the atmospheres of planets and stars. Convection is one of the most studied problem in sciences and engineering due to its enormous practical importance. Yet there are many unresolved issues in th...

[1] We investigate the physics of multiscale convection in Earth’s mantle, characterized by the coexistence of large-scale mantle circulation associated with plate tectonics and smallscale sublithospheric convection. In part 2 of our study, the temporal and spatial evolution of sublithospheric convection is studied using two-dimensional whole mantle convection models with temperatureand depth-d...

Convection in chemical fronts enhances the speed and determines the curvature of the front. Convection is due to density gradients across the front. Fronts propagating in narrow vertical tubes do not exhibit convection, while convection develops in tubes of larger diameter. The transition to convection is determined not only by the tube diameter, but also by the type of chemical reaction. We de...

Linear stability of double diffusive convection of Darcy-Maxwell fluid with Soret and Dufour effects is investigated. The effects of the Soret and Dufour numbers, Lewis number, relaxation time and solutal Darcy Rayleigh number on the stationary and oscillatory convection are presented graphically. The Dufour number enhances the stability of Darcy-Maxwell fluid for stationary convection while it...

We study asymptotic behavior of the global attractors to the Boussinesq system for Rayleigh-B enard convection at large Prandtl number. In particular, we show that the global attractors to the Boussinesq system for Rayleigh-B enard convection converge to that of the in nite Prandtl number model for convection as the Prandtl number approaches in nity. This o ers partial justi cation of the in ni...