The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle v...

Nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. Measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. In this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in p...

A two-part experimental study is conducted on pool boiling heat transfer over enhanced cylindrical microchannel test surfaces with water at atmospheric pressure. In this Part II of the study, the effects of circumferential V-groove microchannels and axial rectangular microchannels are reported. These experiments were performed in the horizontal as well as vertical orientations. The heat transfe...

The characteristics of local heat transfer and pressure drop were investigated experimentally for the vertical up-flow boiling of refrigerant R1234yf in two types of aluminum multi-port extruded tubes having 16 channels with a crosssection of 0.91 × 0.21 mm (tube A) and 40 channels with a cross-section of 0.34 × 0.21 mm (tube B). At an evaporating temperature of 15 °C, the local heat transfer c...

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...

Convective heat transfer of MgO-water nanofluid in a microchannel heat sink is experimentally investigated in various concentrations of 0.01, 0.05, 0.1, and 0.6 wt%. The microchannel consisted of 48 parallel rectangular cross section channels with the height of 800 µm, width of 524 µm and length of 52 mm. A well stability duration (ca. 1 month) was resulted by a 180 min ultra-sonication of the ...

In this study, the behavior of nanoparticles using a numerical model is discussed. For this study a model for the expansion in free convection heat transfer and mix in a rectangular container with dimensions of 1 × 4 cm using Nano-aerosols in the air is going when copper nanoparticles, use and by changing the temperature difference between hot and cold wall, we will examine its impact on the ra...

In this work, the characteristics of flow and heat transfer of a fluid containing nano particles of aluminum oxide with the water volume fraction (0.1-0.2-0.3)(V/V) percent of the reports. The overall heat transfer coefficient, heat transfer and the average heat transfer fluid containing nano water - aluminum oxide in a horizontal double pipe counter flow heat exchanger under turbulent flow con...

the present study investigated the effect of distilled-water/ silver nanofluid on heat transfer in a closed cooling system of one of the electrical energy generation units at isfahan power plant. the difference between this study and previous researches refers to silver properties which have a high thermal conductivity and is non-toxic, hydrophilic and eco-friendly. distilled water/ silver nano...

In this paper the heat transfer characteristics of a two-phase closed thermosyphon over a wide range of heat transfer rates, system pressure, aspect ratios and filling ratios were studied. The experiments focused on the boiling and condensation heat transfer characteristics of a thermosyphon with a copper tube having 25 and 32 mm inside and outside diameters. Distilled water was used as the wor...