Nanofluid

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

Review of Heat Conduction in Nanofluids

Abstract: Nanofluids—fluid suspensions of nanometer-sized particles—are a very important area of emerging technology and are playing an increasingly important role in the continuing advances of nanotechnology and biotechnology worldwide. They have enormously exciting potential applications and may revolutionize the field of heat transfer. This review is on the advances in our understanding of heat-conduction process in nanofluids. The emphasis centers on the thermal conductivity of nanofluids: its experimental data, proposed mechanisms responsible for its enhancement, and its predicting models. A relatively intensified effort has been made on determining thermal conductivity of nanofluids from experiments. While the detailed microstructure-conductivity relationship is still unknown, the data from these experiments have enabled some trends to be identified. Suggested microscopic reasons for the experimental finding of significant conductivity enhancement include the nanoparticle Brownian motion, the Brownian-motion-induced convection, the liquid layering at the liquid-particle interface, and the nanoparticle cluster/aggregate. Although there is a lack of agreement regarding the role of the first three effects, the last effect is generally accepted to be responsible for the reported conductivity enhancement. The available models of predicting conductivity of nanofluids all involve some empirical parameters that negate their predicting ability and application. The recently developed first-principles theory of thermal waves offers not only a macroscopic reason for experimental observations but also a model governing the microstructure-conductivity relationship without involving any empirical parameter.

Wettability Alteration of Sandstone Cores by Alumina-Based Nanofluids

Abstract: Wettability alteration can occur at different stages during the producing life of a reservoir. Oil recovery from oil-wet reservoirs can significantly be increased by altering its wettability from an oil-wet to a strongly water-wet condition. Chemical agents such as surfactants are known as wettability modifiers in oil-wet systems. More recently, nanofluids prepared by dispersing nanoparticles in several liquid agents have been considered as potential wettability modifiers. In this work, the effectiveness of alumina-based nanofluids in altering the wettability of sandstone cores with an induced oil-wet wettability was experimentally studied. Eight nanofluids with different nanoparticles concentration, ranging from 100 ppm to 10000 ppm, were prepared by dispersing alumina nanoparticles in an anionic commercial surfactant. The effect of nanofluids on wettability alteration was investigated by contact angle and imbibition tests, and it was shown that designed nanofluids could significantly change the wettabil...

Numerical simulation for solidification in a LHTESS by means of nano-enhanced PCM

Abstract: In order to saving thermal energy, latent heat thermal energy storage systems (LHTESS) can be utilized. Common phase change material (PCM) has low thermal conductivity. In this paper, CuO nanoparticles have been used to enhance the performance of LHTESS. CuO–water nanofluid properties are estimated by means of KKL. This unsteady process has been simulated by Finite element method. Results prove that solidification process is accelerated by adding CuO nanoparticles in to pure PCM. As number of undulations increases average temperature and total energy profiles reduce while solid fraction profile increases. Also, it can be concluded that highest rate of solidification is obtained for dp = 40 nm.

Applications of nanofluids in solar energy: A review of recent advances

Abstract: Solar energy systems (SESs) are considered as one of the most important alternatives to conventional fossil fuels, due to its ability to convert solar energy directly into heat and electricity without any negative environmental impact such as greenhouse gas emissions. Utilizing nanofluid as a potential heat transfer fluid with superior thermophysical properties is an effective method to enhance the thermal performance of solar energy systems. The purpose of this review paper is the investigation of the recent advances in the nanofluids’ applications in solar energy systems, i.e., solar collectors (SCs), photovoltaic/thermal (PV/T) systems, solar thermoelectric devices, solar water heaters, solar-geothermal combined cooling heating and power system (CCHP), evaporative cooling for greenhouses, and water desalination.