Gravity or buoyancy plays an important role in atmospheric and geophysical flows. The flow is destabilized when heavier or colder fluid is on top of a lighter or hotter fluid, often seen in thermal convection (Fig 1(a)). Convection plays an important role in interiors of many planets and stars, and it is one of the mechanisms for the generation of a magnetic field. Conversely, the flow is stabi...

When a fluid is heated by the absorption of a continuous laser wave, the fluid density decreases in the heated area. This induces a pressure gradient that generates internal motion of the fluid. Due to mass conservation, convection eddies emerge in the sample. To investigate these laser-driven bulk flows at the microscopic scale, we built a setup to perform temperature measurements with a fluor...

The FORTRAN CFD code 3DINAMICS has been developed to simulate momentum, mass, and heat transfer in laminar and turbulent unsteady three-dimensional flows. The code has been successfully applied to the simulation of several engineering flows, particularly we present four different ones: lid-driven cavity, natural convection in a cubical cavity, hydrodynamics in shallow ponds and three-dimensiona...

A thermal lattice Boltzmann method (TLBM) is used for analysis of flow and heat transfer in two-dimensional channels. Simulation results are presented for thermal Couette and thermal Poiseuille channel flows. Analytical solution for temperature field in hydraulically and thermally developed flows are used to verify the current TLBM results. The method is further applied to study the forced conv...

We present a systematic numerical study of two-dimensional axisymmetric accretion flows around black holes. The flows have no radiative cooling and are treated in the framework of the hydrodynamical approximation. The models calculated in this study cover the large range of the relevant parameter space. There are four types of flows, determined by the values of the viscosity parameter α and the...

Recent hydrodynamical simulations of radiatively inefficient black hole accretion flows with low viscosity have demonstrated that these flows differ significantly from those described by an advection-dominated model. The black hole flows are advectiondominated only in their inner parts, but convectively dominated at radii R ∼ > 10RG. In such flows, the radiative output comes mostly from the con...

This paper describes one-dimensional (parallel) laminar and transitional regimes of natural convection in a viscous stably stratified fluid due to temporally-periodic variations in the surface temperature of infinite vertical plates and cylinders. Analytical solutions are obtained for the periodic laminar regime for arbitrary values of stratification, Prandtl number and forcing frequency. The s...