We report experiments on turbulent Rayleigh-Bénard convection of air in a cylindrical large-scale facility with a diameter of 7 meters and Rayleigh numbers up to Ra approximately 10(12). The facility is used to explore the structure of the large-scale circulation for continuously varying aspect ratios between Gamma approximately 1 and Gamma approximately 10. Using autocorrelation functions deri...

Finite amplitude thermal convection is studied in a horizontal layer of infinite Prandtl number fluid with a variable gravity. For the present study, gravity is restricted to vary quadratically with respect to the vertical variable. A perturbation technique based on a small parameter, which is a measure of the ratio of the vertical to horizontal dimensions of the convective cells, is employed t...

The effect of sloping boundaries on thermal convection is studied theoretically and experimentally in the context of a model in which fluid is contained in a differentially heated rectangular box of small aspect ratio (depth/length), inclined at an angle 8 to the vertical. Like its two limiting cases, Benard convection and convection in the vertical slot, there is a steady laminar twodimensiona...

This article presents a numerical study of the doublediffusive mixed convection in a vertical channel filled with porous medium by using non-equilibrium model. The flow is assumed fully developed, uni-directional and steady state. The controlling parameters are thermal Rayleigh number (RaT ), Darcy number (Da), Forchheimer number (F), buoyancy ratio (N), inter phase heat transfer coefficient (H...

an investigation on the thermal performance of the soil as geothermal heat energy storage medium has been conducted. the thermal characteristics of the soil storage and the heat transfer from a heat exchanger in the soil, surrounding and bottom surface will be discussed. this investigation forms a contribution to a project to realize such storage to be charged from a solar heating system. this ...

This paper presents a numerical investigation of the laminar mixed convection flow of a radiating gas in an inclined lid-driven cavity. The fluid is treated as a gray, absorbing, emitting, and scattering medium. The governing differential equations including continuity, momentum and energy are solved numerically by the computational fluid dynamics techniques (CFD) to obtain the velocity and tem...

1State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China 2Department of Mechanics, Sun Yat-Sen University, Guangzhou 510275, China 3Shanghai Institute of Applied Mathematics and Mechanics and Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shangh...

In this paper, we study numerical solutions of the time-space fractional wave equation in a complex domain. The fractional time is taken in the sense of the RiemannLiouville differential operator while the fractional space is assumed in the SrivastavaOwa differential operator. Here we employ some properties of the univalent functions in the unit disk to determine the upper bound of this solutio...

Thermal convection in a fluid layer confined between two horizontal rigid boundaries has been studied with the help of the Floquet theory. The temperature distribution consists of a steady part and an oscillatory time-dependent part. Disturbances are assumed to be infinitesimal. Numerical results for the critical Rayleigh numbers and wave numbers are obtained. It is found that the disturbances ...

Several approaches to numerical modelling of liquid droplet heating and evaporation by convection and radiation from the surrounding hot gas are discussed. The finite thermal conductivity of liquid, recirculation in droplets, and time dependence of gas temperature and the convection heat transfer coefficient are taken into account. For the constant and almost constant convection heat transfer c...