Experimental investigations has been done to find out the heat transfer characteristics and friction factor of water based Al2O3 nanofluids as a coolant in  brazed plate heat exchanger. Plate heat exchanger either use horizontally or vertically. The base plate of the plate heat exchanger was kept inclined at (0⁰, 30⁰ ,60⁰, 90⁰). The experimentation have been done on the two different concentrat...

the subjects of heat transfer and cooling system are very important topics in the internal combustion engines (ice). in modern cooling systems, low weight, small size and high compactness are the critical designing criteria that requires heat transfer enhancement. boiling phenomenon which is occurred in the water jacket of the ice is one of the methods to increase heat transfer in the coolant s...

In this paper, Turbulent mixed convective heat transfer of water and Al2O3 nanofluid has been numerically studied in a horizontal tube under non-uniform heat flux on the upper wall and insulation in the lower wall using mixture model. For the discretization of governing equations, the second-order upstream difference scheme and finite volume method were used. The coupling of pressure and veloci...

Natural convection heat transfer from a single horizontal cylinder and a pair of vertically aligned horizontal cylinders is investigated. Surface heat transfer distributions around the circumference of the cylinders are presented for Rayleigh numbers of 2 x 10, 4 x 10 and 6 x 10 and a range of cylinder spacings of 1.5, 2 and 3 diameters. With a cylinder pairing the lower cylinder is unaffected ...

Nanofluids are two-phase mixtures consisting of small percentages of nanoparticles (sub 1-10 %vol) inside a carrier fluid. The typical size of nanoparticles is less than 100 nm. These fluids have been exhibiting experimentally a significant increase of thermal performance compared to the corresponding carrier fluids, which cannot be explained using the classical thermodynamic theory. This study...

Shell and Tube heat exchangers are the heat exchangers that are most widely used in industries and for other commercial purposes. There are many techniques that have been utilized to enhance the heat transfer performance of the shell and tube heat exchangers. Air bubble injection is one of the promising and inexpensive techniques that can create turbulence in the fluids resulting in to enhancem...

Cooling heat transfer of supercritical CO2 in horizontal straight tubes with wall is numerically investigated by using FLUENT. The results show that almost all models are able to present the trend of heat transfer qualitatively, and the stand k-ε with enhanced wall treatment model shows the best agreement with the experimental data, followed by LB low Re turbulence model. Then further studies a...

The present work is an experimental study of steady state convective heat transfer of de-ionized water with a (0.04% by volume) volume fraction of Al2O3 nanoparticles dispersed to form a nanofluid that flows through an aluminium tube.Laminar fully developed flow heat transfer coefficient of Al2O3 nanoparticles are dispersed in water in circular tube is discussed in this paper. In order to valid...

The present work is an experimental study of steady state convective heat transfer of de-ionized water with a (0.04% by volume) volume fraction of Al2O3 nanoparticles dispersed to form a nanofluid that flows through an aluminium tube.Laminar fully developed flow heat transfer coefficient of Al2O3 nanoparticles are dispersed in water in circular tube is discussed in this paper. In order to valid...

Nanofluids are stable suspensions of nanoparticles in conventional heat transfer fluids (base fluids) that exhibit better thermal characteristics compared to those of the base fluids. It is important to clarify various aspects of nanofluids behavior. In order to identify the thermal and hydrodynamic behavior of nanofluids flowing through non-circular ducts, in the present study the laminar flow...