Nanofluid

About: Nanofluid is a research topic. Over the lifetime, 23986 publications have been published within this topic receiving 677384 citations.

Lattice Boltzmann method simulation for MHD non-Darcy nanofluid free convection

Abstract: Magnetohydrodynamic nanofluid convective flow in cubic porous enclosure is reported. Lattice Boltzmann Method is selected as mesoscopic approach. Brownian motion impact is taken into account via KKL model. Roles of Darcy number ( D a ) , Hartmann number ( H a ) , Rayleigh number ( R a ) , and Al 2 O 3 volume fraction ( ϕ ) are presented. Outputs are illustrated in forms of velocity contours, isokinetic energy, streamlines, isotherms and Nusselt number. Results indicate that temperature gradient over the hot surface augments with rise of Darcy numbers and ϕ while it reduces with augment of Lorentz forces. Nusselt number enhances with increase of buoyancy forces and permeability of porous media. Nanofluid motion enhances with augment of ϕ , D a , R a while it decreases with augment of H a .

Metal oxide-based nanoparticles: revealing their potential to enhance oil recovery in different wettability systems

Abstract: This paper presents systematic studies of hydrophilic metal oxide nanoparticles (NPs) dispersed in brine intended to reveal their potential to enhance oil recovery (EOR) in various rock wettability systems. The stability in suspension (nanofluid) of the NPs has been identified as a key factor related to their use as an EOR agent. Experimental techniques have been developed for nanofluid stability using three coupled methods: direct visual observation, surface conductivity and particle size measurements. The use of a dispersant has been investigated and has been shown to successfully improve metal oxide nanofluid stability as a function of its concentration. The dispersant alters the nanofluid properties, i.e. surface conductivity, pH and particle size distribution. A two-phase coreflood experiment was conducted by injecting the stable nanofluids as a tertiary process (nano-EOR) through core plugs with various wettabilities ranging from water-wet to oil-wet. The combination of metal oxide nanofluid and dispersant improved the oil recovery to a greater extent than either silica-based nanofluid or dispersant alone in all wettability systems. The contact angle, interfacial tension (IFT) and effluent were also measured. It was observed that metal oxide-based nanofluids altered the quartz plates to become more water-wet, and the results are consistent with those of the coreflood experiment. The particle adsorption during the transport process was identified from effluent analysis. The presence of NPs and dispersant reduced the IFT, but its reduction is sufficient to yield significant additional oil recovery. Hence, wettability alteration plays a dominant role in the oil displacement mechanism using nano-EOR.

A Review of Thermal Conductivity Data, Mechanisms and Models for Nanofluids

Abstract: Numerous studies have shown that nanofluids have superb physical properties, among which thermal conductivity has been studied most extensively but remains controversial. In this review article, we first present important milestones in experimental studies that show new features of the thermal conductivity of nanofluids, together with those that show no such special features. After a brief review of the physical mechanisms proposed to explain the thermal conductivity of nanofluids we present a critical review of the classical and new models used to predict the thermal conductivity behavior of nanofluids. We discuss some controversial issues such as data inconsistencies, the sufficiency and suitability of classical and new mechanisms, and the discrepancies between experimental data and model predictions. At the end of our review, we give some directions for future research in nanofluids and to aid researchers in resolving the controversial issues we are still facing in developing nanofluids with superior t...