The presence of particles in liquid-solid fluidized beds enhances the bed heat transfer, because the movement of the particles leads to an increased turbulence in the system. Moreover, the violent movement of the particles has a positive effect on fouling of the heat transfer surface. The aim of this investigation was to perform systematic measurements of bed voidage and heat transfer coeff...

One way to increase the heat transfer is to use perforated twisted tapes with different hole diameters, which largely improve heat transfer with an increase in the heat transfer area at the constant volume and more mixed flow. In the previous studies, the effect of nanofluids with perforated twisted tapes is less studied. In this work, the performance of water / iron oxide nanofluid in a double...

Industrial demands for more compact heat exchangers are a motivation to find new technology features. Electrohydrodynamics (EHD) is introduced as a promising phenomenon for heat transfer enhancement mechanisms. Similar to any new technology, EHD has not been understood completely yet and requires more fundamental studies. In boiling phase change phenomena, nucleation is the dominant mechanism i...

Abstract   An empirical investigation was carried out to study convective heat transfer of nanofluid flow inside an inclined copper tube under uniform heat flux condition. Required data are acquired for laminar and hydrodynamically fully developed flow inside round tube. The stable CuO-base oil nanofluid with different nanoparticle weight fractions of 0.5%, 1% and 2% was produced by means of ul...

The excellent performance of fluidized bed heat exchangers is due to the interaction between particles and heat transfer surface and to the mixing effects in the viscous sublayer. In this paper, the results of experimental investigations on heat transfer for a wide range of Newtonian and non-Newtonian (shear-thinning power law) fluids are presented. New design equations have been developed ...

  In this numerical study the the heat transfer and laminar nanofluid flow in the three-dimensional microchannels with triangular cross-section is simulated. For increase the heat transfer from the walls of the channel, semiattached & offset mid- truncated rib,s Placed in the canal, and the tooth geometry and the impact is studied. In this study, the water is base fluid, and the influence of th...

in the presented research, heat transfer of a mobile electrolyte alkaline fuel cell (afc) (which the electrolyte has cooling role of system) has been considered. proper control volumes of system with specific qualification have been chosen. consequently, heat and mass transfer in control volumes have been assessed. considerations on them and contributed models lead to approve a double tube heat...

high temperatures are often encountered in almost all of the combustion systems, therefore, thermal radiation heat transfer can influence the droplets heat up rate and consequently their life time. in this paper, the effect of thermal radiation heat transfer is investigated for two cases of directional and spherically symmetric illuminations. the flow and temperature fields insdie and outside o...

The present study attempts to improve heat transfer efficiency of a domestic gas burner by enhancing heat transfer from flue gases. Heat transfer can be augmented using the obstacles that are inserted into the flow field near the heated wall of the domestic gas burner. First, to achive the maximum efficiency, the insert geometry is optimized by the multi-objective genetic algorithm so that heat...

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 ...