This study aims to analytically measure the fully developed laminar flow and heat transfer water-based nanofluids, Cu, CuO, Al2O3, within a micropipe with constant flux, under temperature jump slip rate boundary conditions. Knudsen number, nanoparticle volumes, ratios of liquid layer thickness particle radius are assumed, 0, 0.02, 0.04; 0%, 4%, %8, 0.1, 0.2, 0.4, respectively. The findings sugg...

The study of the influence nanoparticle volume fraction and aspect ratio microchannels on fluid flow heat transfer characteristics nanofluids in is important optimal design dissipation systems with high flux. In this work, computational dynamics method was adopted to simulate two types water-Al2O3 different fractions five microchannel sinks ratios. Results showed that increasing reduced average...

The conventional liquids have some limitations regarding the thermal properties. The nanoparticles addition is one of the techniques which can modify them. In this research, heat transfer coefficient (h) and pressure loss (Δp) of various nanofluids containing Al2O3, SiO2 and MgO nanoparticles dispersed in water in an annular tube with constant wall temperature were numerically considered. Accor...

Gold catalysts supported on γ-Al2O3 (Au/γ-Al2O3) were prepared by deposition-precipitation of aqueous HAuCl4 and, alternatively, by deposition of Au(CH3)2(acac) from pentane solution. The samples were characterized by in situ XANES and temperature-programmed reduction and by their performance as CO oxidation catalysts at room temperature. The Au was found to be present as Au(III) in both as-pre...

In this study, the convective heat transfer and pressure drop in laminar flow of Al2O3/water and CuO/water nanofluids through square and triangular cross-sectional ducts have been numerically investigated using new technique. It has been assumed that there is constant heat flux boundary condition at walls. In addition, to include the presence of nanoparticles, the dispersion model has been used...

The high-temperature oxidation of Hf-modified NiAl alloy at 950 °C results in the formation γ-Al2O3 and θ-Al2O3. Exclusive HfO2 particles is observed adherent γ-Al2O3/NiAl interface. By contrast, θ-Al2O3/NiAl interface multi-layered oxide growth consisting alternate thin thick layers θ-Al2O3 NiAl2O4 along with dispersed layers. This difference elucidated by first-principle calculations showing ...

nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with a typical size of less than 100 nm in the conventional heat transfer fluids.this article aims to investigate the overall and convection heat transfer coefficient and nusselt number of al2o3-water nanofluid flowing in a horizontal double pipe heat exchanger under turbulent flow (...