Nanofluids are engineered fluids that contain a suspension of nanoparticles in a pure substance. Nanoparticles can be any variety of metals, metal oxides, or ceramics. They have been shown to increase heat transfer properties such as thermal conductivity, convective heat transfer, and critical heat flux(CHF). An optical probe used to detect phase was used to measure the void fraction during boi...

The thermal conductivity, thermal diffusivity and heat capacity per unit volume of dunite rocks taken from Chillas near Gilgit, Pakistan have been measured simultaneously using transient plane source technique. The temperature dependence of thermal transport properties is studied in the temperature range 83-303 K. Different relations for the estimation of thermal conductivity are also tested. T...

Transient natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity, and the thermal expansion coefficient of Al2O3-water nanofluid. The study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ ϕ ≤ 7%), the enclosure aspect ratio (AR =1), and temperature differences between the cold a...

in this paper, wavelet collocation method has been used to solve nonlinear fin problem with temperature dependent thermal conductivity and heat transfer coefficient. thermal conductivity of fin materials varies any type so that we consider thermal conductivity as the general function of temperature.  here we consider three particular cases, where we assume that thermal conductivity is constant,...

in this study, thermal performance of a cylindrical heat pipe is investigated numerically. three different types of water based nanofluids, namely (al2o3+water), (diamond+water) and (multi-wall carbon nano tube (mwcnt) +water) have been used. the influence of using the simple nanofluids and mwcnt nanofluid on the heat pipe characteristics such as liquid velocity, pressure profile, temperature p...

A nonsimilarity analysis is performed to investigate the laminar, free convection boundary layer flow over a permeable isothermal truncated cone in the presence of a transverse magnetic field effect. A suitable set of dimensionless variables is used and non-similar equations governing the problem are obtained. Fourth order Runge-Kutta with shooting technique is employed for the numerical soluti...

Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by volume). Since CHF is the upper limit of nucleate boiling, such enhancement offers the potential for major performance improvement in many practical applications that use nucleat...

 This work presents a model for calculating the effective ‎thermal conductivity of nanofluids. The proposed model ‎includes the effects of nanoparticles and thermal conductivity ‎base fluid.We will focus on experimental of the volume ‎concentration parameter and temperature on thermal ‎conductivity, nano-fluid combination and Multi-Walled ‎Carbon nanotubes-Oxide / Copper-paid deionized Water. T...

7 Generation of entropy and transfer of heat during forced convection of a nanofluid through a partially-filled 8 porous channel are investigated theoretically. The problem includes a fully developed flow in a channel with a 9 central porous insert and under constant heat flux boundary condition. The system is assumed to be under local 10 thermal non-equilibrium and the solid and nanofluid phas...

In this investigation, the analysis of heat transfer coefficient a shell, helically coiled convergent-divergent tube exchanger has been carried out by utilizing Al2O3/water nanofluid. The nanofluid was prepared using two-stage technique with proportions 0.1vol%, 0.3vol%, and 0.5vol%. inner coefficient, overall Nusselt number were analyzed it found that is increased, increase dean particle volum...