in this paper, overall heat transfer coefficient and friction factor of water based γ-al2o3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. for better dispersion of γ-al2o3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kw and frequency of 35 khz) were implemented. the stabi...

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...

BACKGROUND Aryl sulfides have significant importance from biological and pharmaceutical aspects. Transition metal-catalyzed carbon-sulfur cross-coupling reaction represents an important tool for the synthesis of sulfides. Among various transition metals, copper salts or oxides have found vast applicability. RESULTS A simple procedure for the preparation of poly-ionic amberlite resins embedded...

rheological characteristics of al2o3, cuo and tio2 nano particles were investigated in oil asthe base fluid at 1 and 2 wt.%. constitutive relations for non-newtonian fluid were discussedbased on the power-law model. measured viscosities of each nanofluid were used to evaluatethe power-law and consistency index. results indicated that the nanofluid viscosity decreasedby increasing the concentrat...

The abrasion is a significant issue, especially in machining of rigid steels. A functional and suitable approach for enhancing the heat transfer from machining area is using an intermediate fluid with higher heat transfer potential instead of common fluids. The objective of this experimental study is to discuss production, stability and thermal conductivity examination of water/graphene oxide n...

Experiments are undertaken to determine the efficiency of an evacuated tube solar collector using water-based Titanium Oxide (TiO2) nanofluid at the Pekan Campus (3 ̊32’ N, 103 ̊25’ E), Faculty of Mechanical Engineering, University Malaysia Pahang, for the conversion of solar thermal energy. Malaysia lies in the equatorial zone with an average daily solar insolation of more than 900 W/m2, which c...

Abstract Nowadays, applications of turbulent fluid flow in removing high heat flux rib-roughened narrow channels are drawing much interest. In this work, an improved version the κ-ε turbulence model is proposed for better prediction thermal–hydraulic characteristics inside (pitch-to-rib height ( p/k ) ratio = 10 and 20) (channel height, H 1.2 mm 3.2 mm). For this, four parameters, C μ , ε1 ε2 σ...

In this work, a two-dimensional analysis is used to study the thermal performance of a cylindrical heat pipe utilizing nanofluids. Three of the most common nanoparticles, namely Al2O3, CuO, and TiO2 are considered as the working fluid. A substantial change in the heat pipe thermal resistance, temperature distribution, and maximum capillary heat transfer of the heat pipe is observed when using a...

in our current study, supercritical water impregnation (scwi) was introduced as a unique catalyst preparation method by employing the high diffusivity property of supercritical water. the method allows nano-particles to place on support surfaces in extremely dispersed conditions. the silica-based nanocatalyst granules for this purpose were prepared by initial impregnation of highly porous silic...