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 ...

this paper presents a numerical simulation of developing flow and heat transfer of a viscoelastic fluid in a rectangular duct. in fully developed flow of a viscoelastic fluid in a non-circular duct, secondary flows normal to the flow direction are expected to enhance the rate of heat and mass transfer. on the other hand, properties such as viscosity, thermal conductivity, specific heat and rela...

experimental study of effective thermal conductivity of zno/eg nanofluid is presented in thisresearch. the nanofluid was prepared by dispersing zno nanoparticles in ethylene glycol using asonicator and adding surfactant. ethylene glycol based nanofluid containing zno nanoparticlewith a nominal diameter of 18 nm at different solid volume fractions (very low to high) atvarious temperatures was ex...

the fluid flow and heat transfer in a three-dimensional microchannel filled with al2o3- water nanofluid is numerically investigated. the hybrid scheme is used to discretize the convection terms and simpler algorithm is adopted to couple the velocity and pressure field in the momentum equations. the thermal and flow fields were analyzed using different volume fractions of nanoparticles and diffe...

The effect of γ-Al2O3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-Al2O3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. Since the properties of γ-Al2O3-water nanofluids were variable, they were ...

transfer table is an essential stage between roughing and finishing rolling stands in a hot-strip rolling mill. high temperature and long time that strip is exposed to air at this stage cause a considerable heat loss that accounts for uneven temperature distribution, non-uniform surfaces, reduced product quality and increased production costs. using thermal shields on the transfer table is cons...