in this work a numerical study of thermal and fluid dynamics behavior of natural air convection in a square cavity in a laminar flow is presented, by finite volume method. the square cavity has two walls heated with different temperatures and two isolated walls. the numerical simulation is made up of several rayleigh numbers to . flow and isotherm lines are presented and analyzed. the numerical...

We offer a unifying theory for turbulent purely internally heated convection, generalizing the theories of Grossmann and Lohse (2000, 2001) Rayleigh--B\'enard turbulence Shishkina, (2016) horizontal which are both based on splitting kinetic thermal dissipation rates in respective boundary bulk contributions. obtain mean temperature system Reynolds number (which response parameters) as function ...

Thermal convection in a rotating cylinder with a radius-to-height aspect ratio of Γ=4 for fluids with large Prandtl number is studied numerically. Centrifugal buoyancy effects are investigated in a regime where the Coriolis force is relatively large and the onset of thermal convection is in the so-called wall modes regime, where pairs of hot and cold thermal plumes ascend and descend in the cyl...

in present paper, a numerical analysis for a rectangular cavity filled with a anisotropic porous media has been studied. it is assumed that the horizontal walls are adiabatic and impermeable, while the side walls of the cavity are maintained at constant temperatures and concentrations. the buoyancy force that induced the fluid motion are assumed to be cooperative. in the two extreme cases of he...

A shadowgraph optical setup is used to study the time evolution of Soret induced convection in a colloidal suspension. We obtain a scale invariant behavior for the solutal Nusselt number as a function of the Rayleigh number. In a typical Rayleigh-Bénard experiment a horizontal slab of a fluid is contained between a top and bottom plates maintained at two different temperatures (higher temperatu...

A lattice Boltzmann model is developed by coupling the density (D2Q9) and the temperature distribution functions with 9-speed to simulate the convection heat transfer utilizing Al2O3-water nanofluids in a square cavity. This model is validated by comparing numerical simulation and experimental results over a wide range of Rayleigh numbers. Numerical results show a satisfactory agreement between...

In present paper, a numerical analysis for a rectangular cavity filled with a anisotropic porous media has been studied. It is assumed that the horizontal walls are adiabatic and impermeable, while the side walls of the cavity are maintained at constant temperatures and concentrations. The buoyancy force that induced the fluid motion are assumed to be cooperative. In the two extreme cases o...

We demonstrate the specific non-Boussinesq roles played by various fluid properties in thermal convection by allowing each of them to possess, one at a time, a temperature dependence that could be either positive or negative. The negative temperature dependence of the coefficient of thermal expansion hinders effective thermal convection and reduces the Nusselt number, whereas the negative depen...