Divya P. Barai

Bio: Divya P. Barai is an academic researcher from Rashtrasant Tukadoji Maharaj Nagpur University. The author has contributed to research in topics: Nanofluid & Thermal conductivity. The author has an hindex of 9, co-authored 37 publications receiving 284 citations. Previous affiliations of Divya P. Barai include Laxminarayan Institute of Technology.

Reduced Graphene Oxide-Fe3O4 Nanocomposite Based Nanofluids: Study on Ultrasonic Assisted Synthesis, Thermal Conductivity, Rheology, and Convective Heat Transfer

Abstract: The present work deals with the preparation of reduced graphene oxide-Fe3O4 (rGO-Fe3O4) nanocomposite and its nanofluid by an ultrasound assisted method for convective heat transfer study. Formatio...

Performance evaluation of nanofluids in solar thermal and solar photovoltaic systems: A comprehensive review

Abstract: Nanofluids, due to their superior thermal properties, have immense applications in heat transfer process. In view of this, nanofluids, as working fluids in solar thermal systems, have gained importance. This review emphasizes the properties of nanofluids for solar thermal applications as well as typical nanomaterials and analyses experimental and numerical investigations on solar thermal systems utilizing nanofluids along with typical experimental setups and calculation methods used for determination of the performance of nanofluids in the same. The effect of nanoparticles concentration, flowrate, ambient temperature, solar intensity and inlet temperature on the solar thermal system performance utilizing nanofluids is also discussed. Further, challenges occurring during application of nanofluids in solar thermal systems are specified along with recommendations for scaling up of nanofluid-based solar thermal systems.

A Review on Graphene Derivatives-Based Nanofluids: Investigation on Properties and Heat Transfer Characteristics

Abstract: The fact that some of solid materials with suitable phases possess higher thermal conductivity than liquids gave rise to their utilization in heat transfer processes. Fluids that contain nanopartic...

A Benchmark Study on the Thermal Conductivity of Nanofluids

Abstract: This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about the sample average with only few outliers. The thermal conductivity of the nanofluids was found to increase with particle concentration and aspect ratio, as expected from classical theory. There are (small) systematic differences in the absolute values of the nanofluid thermal conductivity among the various experimental approaches; however, such differences tend to disappear when the data are normalized to the measured thermal conductivity of the basefluid. The effective medium theory developed for dispersed particles by Maxwell in 1881 and recently generalized by Nan et al. [J. Appl. Phys. 81, 6692 (1997)], was found to be in good agreement with the experimental data, suggesting that no anomalous enhancement of thermal conductivity was achieved in the nanofluids tested in this exercise.

Thermal conductivity of nanoparticle suspensions

Abstract: We describe an optical beam deflection technique for measurements of the thermal diffusivity of fluid mixtures and suspensions of nanoparticles with a precision of better than 1%. Our approach is tested using the thermal conductivity of ethanol-water mixtures; in nearly pure ethanol, the increase in thermal conductivity with water concentration is a factor of 2 larger than predicted by effective medium theory. Solutions of C60–C70 fullerenes in toluene and suspensions of alkanethiolate-protected Au nanoparticles were measured to maximum volume fractions of 0.6% and 0.35vol%, respectively. We do not observe anomalous enhancements of the thermal conductivity that have been reported in previous studies of nanofluids; the largest increase in thermal conductivity we have observed is 1.3%±0.8% for 4nm diam Au particles suspended in ethanol.

Environmental Science (AS)

Abstract: There will be one written paper of three hours duration carrying 70 marks divided into two parts. Part 1 (20 marks) will consist of compulsory short answer questions on the entire syllabus. Part 2 (50 marks) will consist of three sections. Each section will have three questions. The candidates will be expected to answer five questions in all choosing at least one from each section. Project work will carry 30 marks. The project needs to be done under the supervision of the teacher. The project work will be evaluated by a Visiting Examiner (who has expertise in that specific area), appointed locally and approved by the Council.

An updated review of nanofluids in various heat transfer devices

Abstract: The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in the later part of the twentieth century This is evident from the increased number of studies related to nanofluids published annually The increasing attention on nanofluids is primarily due to their enhanced thermophysical properties and their ability to be incorporated into a wide range of thermal applications ranging from enhancing the effectiveness of heat exchangers used in industries to solar energy harvesting for renewable energy production Owing to the increasing number of studies relating to nanofluids, there is a need for a holistic review of the progress and steps taken in 2019 concerning their application in heat transfer devices This review takes a retrospective look at the year 2019 by reviewing the progress made in the area of nanofluids preparation and the applications of nanofluids in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling This review aims to update readers on recent progress while also highlighting the challenges and future of nanofluids as the next-generation heat transfer fluids Finally, a conclusion on the merits and demerits of nanofluids is presented along with recommendations for future studies that would mobilise the rapid commercialisation of nanofluids