A numerical study to investigate the steady laminar natural convection flow in a square cavity with uniformly and non-uniformly heated bottom wall, and adiabatic top wall maintaining constant temperature of cold vertical walls has been performed. A penalty finite element method with bi-quadratic rectangular elements has been used to solve the governing mass, momentum and energy equations. The n...

Laminar, steady-state, natural convection of power-law fluids in 2-D trapezoidal enclosures with a heated bottom wall, adiabatic top wall and cooled inclined sidewalls has been analyzed for the first time based on numerical simulations range different values nominal Rayleigh number (i.e. 103?Ra?105), index 0.6?n?1.8), Prandtl Pr=10, 102,103) sidewall inclination angle 30°???60°). It found that ...

For two-dimensional Rayleigh-B\'{e}nard convection, classes of unstable, steady solutions were previously computed using numerical continuation (Waleffe, 2015; Sondak, 2015). The `primary' solution bifurcates from the conduction state at $Ra \approx 1708$, and has a characteristic aspect ratio (length/height) approximately $2$. primary corresponds to one pair counterclockwise-clockwise convecti...

This work is about studying the natural convection of two-dimensional steady state non-Newtonian power law fluid numerically. The inner cylinder was put eccentrically into outer one. cylinders are held at constant temperatures with one heated isothermally temperature Th and cooled Tc (Th>Tc). simulations have been taken for parameters 103?Ra?105, 10?Pr?103, 0.6?n?1.4, 0???0.9 an inclination ...

Turbulent convection is often present in liquids with a kinematic viscosity much smaller than the diffusivity of the temperature. Here we reveal why these convection flows obey a much stronger level of fluid turbulence than those in which kinematic viscosity and thermal diffusivity are the same; i.e., the Prandtl number Pr is unity. We compare turbulent convection in air at Pr=0.7 and in liquid...

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Measurements of the Nusselt number Nu and of properties of the large-scale circulation (LSC) for turbulent Rayleigh–Bénard convection are presented in the presence of rotation about a vertical axis at angular speeds 0 Ω <∼ 2 rad s−1. The sample chamber was cylindrical with a height equal to the diameter, and the fluid contained in it was water. The LSC was studied by measuring sidewall temperat...

We perform two-dimensional direct numerical simulations to study the effect of porous media on global transport properties and flow structures in Rayleigh–Bénard (RB) convection at different Prandtl numbers. The are carried out a square RB cell with uniformly placed circular obstacles, where porosity spans between ϕ=1 ϕ=0.75 Rayleigh number Ra fixed 108, two high numbers (10,4.3) low (0.03,0.1)...

Very large eddy simulations of high-aspect-ratio unbounded Rayleigh-Bénard convection for Pr=0.71 over a 10-decade range of Rayleigh numbers (Ra=10(5)-10(15)) reveal a consolidation and dramatic thinning of the wall boundary layer with an increase in the Ra number. The fingerlike plumes between planform structures become also thinner, more distant, but much more vigorous. The Ra exponent in the...