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...

Nanofluids, colloidal suspensions consisting of base fluids and nanoparticles, are a new generation of engineering working fluids. Nanofluids have shown great potential in heat/mass transfer applications. However, their practical applications are limited by the high production cost and low stability. In this study, a low-cost agricultural waste, rice husk ash (RHA), was used as a silicon source...

A theoretical analysis has been made to explore thermal entrance region heat transfer in nanofluids. The numerical model used in this paper is based on the Buongiorno model for convective heat transfer in nanofluids with modifications to fully account for the effects of nanoparticles volume fraction distributions on the continuity, momentum and energy equations. Numerical investigations have be...

The success of quenching process during industrial heat treatment mainly depends on the heat transfer characteristics of the quenching medium. In the case of quenching, the scope for redesigning the system or operational parameters for enhancing the heat transfer is very much limited and the emphasis should be on designing quench media with enhanced heat transfer characteristics. Recent studies...

Nanofluids are new generation heat transfer fluids and have opened a new horizon in the areas of heat transfer applications. Nanofluids are prepared by dispersing nano-sized metallic particles in conventional fluids of heat transfer. Heat transfer performance of nanofluid depends primarily on its thermo physical properties like viscosity, thermal conductivity, specific heat and density. Viscosi...

The possibilities offered by catalytic γ-Al2O3 substrates are explored, and the mechanism governing graphene formation thereon is elucidated using both numerical simulations and experiments. The growth scheme offers metal-free synthesis at low temperature, grain-size customization, large-area uniformity of electrical properties, single-step preparation of graphene/dielectric structures, and rea...

Transformation of Al(NO3)3∙9H2O (upon heating in the range of 20-1200 °C) into blends of amorphous and crystalline boehmite (210-525 °C), amorphous alumina and crystalline γ-Al2O3 (850 °C), and crystalline α-Al2O3 (1100 °C) was analyzed using X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), infrared (IR) spectroscopy, thermogravimetry, and low-temperature nitro...

Articles you may be interested in Shear-rate dependent effective thermal conductivity of H2O+SiO2 nanofluids Sequential bond energies and barrier heights for the water loss and charge separation dissociation pathways of Cd2+(H2O) n , n = 3–11 The effect of particle size on the effective thermal conductivity of Al 2 O 3-water nanofluids The International Association for the Properties of Water a...

Objetivo: En este estudio se evaluó el efecto de la modificación con óxido zinc del soporte convencional en catalizadores hidrodesulfuración (HDS) a base polioxometalato Anderson-Evans NiMo5W. Metodología: Los fueron sintetizados por método co-precipitación NiMo5W sobre Al2O3. caracterizaron FRX, MEB/EDS, CHONS, propiedades texturales, FT-IR, Raman y titulación potenciométrica n-butilamina. Res...

The optimization of the poor heat transfer characteristics of fluids conventionally employed in solar devices are at present one of the main topics for system efficiency and compactness. In the present work we investigated the optical and thermal properties of nanofluids consisting in aqueous suspensions of single wall carbon nanohorns. The characteristics of these nanofluids were evaluated in ...