Eulerian-Eulerian multi-phase mixture model is applied to numerically analyse the turbulent flow and heat transfer behaviours of water based Al2O3 and TiO2 nanofluids in a pipe. The main goal of the present work is to investigate the effects of volume concentrations, Brownian motion and size diameter of nanoparticles on the flow and heat transfer. Analysis of entropy generation is presented in ...

The CFD simulation of heat transfer characteristics of a nanofluid in a circular tube under constant heat flux was considered using Fluent software (version 6.3.26) in the laminar flow. Al2O3 nanoparticles in water with concentrations of 0.5%, 1.0%, 1.5%, 2% and 2.5% were used in this simulation. All of the thermo-physical properties of nanofluids were assumed to be temperature independent. Two...

common heat transfer fluids such as water, ethylene glycol, and engine oil have limited heat transfer capabilities due to their low heat transfer properties. nanofluids are suspensions of nanoparticles in base fluids, a new challenge for thermal sciences provided by nanotechnology. in this study, we are to optimize and report the effects of various parameters such as the ratio of the thermal co...

The convective heat transfer and pressure drop of water based Al2O3 nanofluid in a horizontal tube subject to constant wall temperature condition is investigated by computational fluid dynamic (CFD) method. The Al2O3 nanofluid at five volume concentration of 0.1, 0.5, 1.0, 1.5 and 2 % are applied as a non Newtonian power law and Newtonian fluid with experimentally measured properties of density...

Surface wettability of materials is important in a myriad of HVAC&R processes. This study is focused on how to manipulate wettability by nanofluid boiling nanoparticle deposition on aluminum surfaces. The focus is on aluminum, because it is commonly used as the material for heat transfer in air conditioning and refrigeration systems. The boiling deposition process occurs under atmospheric press...

For a solar thermal system, increasing the heat transfer area can increase the output temperature of the system. However, this approach leads to a bigger and bulkier collector. It will then increase the cost and energy needed to manufacture the solar collector. This study is carried out to estimate the potential to design a smaller solar collector that can produce the same desired output temper...

The thermal performances of a minichannel heat sink are experimentally investigated for cooling of electronics using nanofluid coolant instead of pure water. The Al2O3–H2O nanofluid including the volume fraction ranging from 0.10 to 0.25 vol.% was used as a coolant. The effects of different flow rates of the coolant on the overall thermal performances are also investigated. The flow rate was ra...

The entropy generation based on the second law of thermodynamics is investigated for turbulent forced convection flow of ZrO2-water nanofluid through a square pipe with constant wall heat flux. Effects of different particle concentrations, inlet conditions and particle sizes on entropy generation of ZrO2-water nanofluid are studied. Contributions from frictional and thermal entropy generations ...

Dynamic viscosity values for three particular water-based nanofluids have been experimental determined using a commercial ‘piston-type’ viscometer. Viscosity data, expressed as a function of temperature and particle volume fraction, are presented for 29nm particle-size CuO-water and Al2O3-water with 36nm and 47nm particle-sizes, temperatures up to 75°C and particle volume fraction up to 9%. In ...

Thermal enhancement of a single mini channel in Proton Exchange Membrane Fuel Cell (PEMFC) cooling plate is numerically investigated. In this study, low concentration of Al2O3 in Water Ethylene Glycol mixtures is used as coolant in single channel of carbon graphite plate to mimic the mini channels in PEMFC cooling plate. A steady and incompressible flow with constant heat flux is assumed in the...