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...

natural convection heat transfer has many applications in different fields of industry; such as cooling industries, electronic transformer devices and ventilation equipment; due to simple process, economic advantage, low noise and renewed retrieval. recently, heat transfer of nanofluids have been considered because of higher thermal conductivity coefficient compared with those of ordinary fluid...

This paper experimentally studies the heat absorption performance of a heat sink with vertical embedded heat pipes in the aluminum blade. The cooling system with embedded heat pipes distributes heat from the CPU to both the base plate and the heat pipes, and then transfer heat from fins to the Environment. The thermal resistance and heat transfer coefficient are evaluated for natural convection...

Heat losses from a trough cavity receiver were investigated in order to eventually optimise the reactor geometry for ammonia-based solar energy storage with troughs, which are prominent in the SEGs plants of California. To this end, experiments were performed with a small-scale receiver containing heating elements. This gave free convection loss coefficient values from 0.3 to 11.8 W/(m.C) from ...

An experimental study is reported on natural convection heat transfer from a helical heating coil to the surrounding fluid. The coil is heated electrically and the surrounding fluid is selected to be water. The range of parameters are: Rayleigh number, 879 ?£ Ra ?£ 780168, Prandtl number, 4.22 ?£ Pr ?£ 10.02, dimensionless coil diameter,7.69 ?£ Dave /d ?£ 10.77, number of coil rings, 2 ?£ N ?£ ...

mixed convection fluid flow and heat transfer of water-al2o3 nanofluid inside a lid-driven square cavity has been examined numerically in order to find the optimal distribution of discrete heat sources on the wall of a cavity. the effects of different heat source length, richardson number and grashof number on optimal heat source location has been investigated. moreover, the average nusselt num...

Heat and vapour convective surface coefficients are required in practically all heat and vapour transport calculations. In building envelope research, such coefficients are often assumed constants for a set of conditions. Heat transfer surface coefficients are often determined using empirical correlations based on measurements of different geometry and flows. Vapour transfer surface coefficient...

Nanofluids, in which nano-sized particles (typically less than 100 nm) are suspended in liquids, have emerged as a possible effective way of improving the heat transfer performance of common fluids. In this paper a numerical study is performed to analyze the wall shear stress and heat transfer coefficient of γAl2O3-water nanofluids under laminar forced convection through a circular pipe. It is ...

The aim of this paper is to investigate the effect of variable viscosity on free convective heat and mass transfer from a horizontal plate embedded in a saturated porous medium. The governing equations of continuity, momentum, energy and concentration are transformed into non linear ordinary differential equations using similarity transformations and then solved by using Runge – Kutta – Gill me...