A coupled molecular dynamics (MD)-stochastic model has been developed for predicting the thermal conductivity of a hypothetical water based Zn-nanofluid taking into account the heat transfer during and after collision of the nanoparticles with the heat source. The model has predicted a somewhat lower enhancement in thermal conductivity of water based Zn-nanofluid compared to water based Cu-nano...

An overview of systematic studies that address the complexity of nanofluid systems and advance the understanding of nanoscale contributions to viscosity, thermal conductivity, and cooling efficiency of nanofluids is presented. A nanoparticle suspension is considered as a three-phase system including the solid phase (nanoparticles), the liquid phase (fluid media), and the interfacial phase, whic...

The thermal conductivity of a fluid can be significantly enhanced by dispersing nano-sized particles in it, and the resultant fluid is termed as "nanofluid". A theoretical model for estimating the thermal conductivity of a nanofluid has been proposed here. It is based on the mechanism that evenly dispersed nanoparticles within a nanofluid undergo Brownian motion in course of which the nanoparti...

Convective heat transfer can be enhanced by changing flow geometry and/or by enhancing thermal conductivity of the fluid. This study proposes simultaneous passive heat transfer enhancement by combining the geometry effect utilizing nanofluids inflow in coils. The two nanofluid suspensions examined in this study are: water-Al2O3 and water-CuO. The flow behavior and heat transfer performance of t...

Heat transfer improvement in circular pipe by using nanofluid and twisted tape is presented in this review paper. Experimental and numerical studies are incorporated involving both the range of turbulent and laminar flow. Effect of type and volume fraction of nanofluid on performance of heat transfer was referred along with the length and twist ratio of the tape through the pipe on heat transfe...

Experimental investigations of heat transfer coefficient of CuO/Water nanofluid are reported in this paper. The heat transfer coefficient of the CuO/water was measured with the help of double pipe heat exchanger. The nanofluid was prepared by dispersing a CuOnano particle in deionized water. CuO/water nanofluid with a nominal diameter of 27nm at different volume concentrations (0.1 &0.3 vol.%) ...

A two-phase flow experiment using air and water-based γ-Al2O3 nanofluid was conducted to observe the basic hydraulic phenomenon of nanofluids. The local two-phase flow parameters were measured with a conductivity double-sensor two-phase void meter. The void fraction, interfacial velocity, interfacial area concentration, and mean bubble diameter were evaluated, and all of those results using the...

This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study mea...