The Role of Nanofluids in Renewable Energy Engineering

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Energy and Catalysis".

Deadline for manuscript submissions: closed (28 February 2023) | Viewed by 28348

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Guest Editor
College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao, China
Interests: mathematical physics; nonlinear waves; numerical simulations; perturbation methods; single- and multi-phase thermofluids; magnetohydrodynamics; nanofluids
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Guest Editor
Department of Mechanical Engineering, University of California, Riverside, CA 92521, USA
Interests: porous media; multiphase transport; aircraft brakes; micro cantilever based biosensors; biofilms; macromolecule transport through arteries; cooling enhancement investigations; modeling of tissue and organs; natural convection in complex configurations; analysis of porous insulations; heat flux applications; free surface flows; flat-shaped heat pipes; thermal design and modeling; feasibility; optimization; parametric studies for various engineering applications and power electronics
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Guest Editor
Basic Science, Faculty of Engineering, The British University in Egypt, Al-Shorouk City, Cairo 11837, Egypt
Interests: applied mathematics; fluid mechanics; blood flows; nanofluids
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Special Issue Information

Dear Colleagues,

Nanofluid flows inherently involve multi-scale and complex physics. A wide variety of modelling and experimental techniques have been already applied to the investigation of nanofluids from the fundamental and applied viewpoints. Physical understanding and research tools have been developed considerably and further major contributions are expected to be made.

In recent years, thermal technology has faced various challenges, and obtaining a higher heat transfer rate is a major problem. The higher temperatures achieved through the combustion of fossil fuels are often not readily achieved by renewable energies. Nanofluids are beneficial in resolving these issues. The basic concept of heat transfer enhancement by nanofluids is now well established. Some important areas still require further investigation, in order to apply nanofluids to energy technologies. It involves interactions between the nanoparticles and the base fluid and their subsequent influences upon heat convection. Further, the large-scale utilisation of nanofluids in renewable energy technologies remains a largely unexplored area. The former leads to investigations on the modifications of fluid and flow behaviours in nanofluids, while the latter involves studies of nanofluids in solar thermal and geothermal technologies, heat storage and networks as well as a wide range of technologies for heat recovery. An ongoing challenge on all of these fronts is the development of accurate and yet affordable computational tools that can predict the heat transfer behaviours of nanofluids. This, in turn, requires the further experimental examination of nanofluids at the system level, such as those in solar thermal collectors and geothermal boreholes and other large-scale renewable energy systems.

The decarbonisation of energy through the transition from fossil fuels to renewables is a tremendous task that faces the engineering research community. Thermal energy constitutes a major fraction of the consumed energy in many parts of the world and is a significant contributor to the emission of greenhouse gases. Many countries have recently decided to decarbonise their heat sectors. As a result, carbon-free thermal technologies such as solar thermal, geothermal, heat pumps, heat storage, and heat networks are receiving ever-increasing attention. Central to all these is the problem of heat transfer.

This Special Issue aims to bring together the latest research findings on heat transfer by nanofluids with a strong emphasis on the problems related to renewable energy.

More specifically, modelling and experimental works on the following topics are of immediate interest. For instance:

  • Numerical simulation related to the potential applications of nanofluids engineering;
  • Analytical and numerical models for the applications of nanofluids;
  • The application of novel nanofluids to renewable energy engineering;
  • The rheology of nanofluids in renewable energy engineering;
  • The application of Hybrid nanofluids;
  • Thermo-hydraulics of nanofluids in renewable energy technologies;
  • Techno-economics of nanofluids in renewable energy systems;
  • The fouling and clustering of nanoparticles in renewable energy systems.

Further, this Special Issue welcomes contributions on micro-, meso- and macro-scale modelling approaches to heat transfer in nanofluids and those on the novel numerical, experimental and theoretical techniques pertinent to nanofluids.

Dr. M. M. Bhatti
Prof. Dr. Kambiz Vafai
Dr. Sara I. Abdelsalam
Guest Editors

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Keywords

  • Nanofluids and Hybrid nanofluids
  • Magnetohydrodynamics
  • Porous media
  • Nanotechnology
  • Biological flows
  • Renewable Energy Engineering
  • Shape effects of nanoparticles
  • Numerical and analytical simulation

Published Papers (14 papers)

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Editorial

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4 pages, 192 KiB  
Editorial
The Role of Nanofluids in Renewable Energy Engineering
by Muhammad Mubashir Bhatti, Kambiz Vafai and Sara I. Abdelsalam
Nanomaterials 2023, 13(19), 2671; https://doi.org/10.3390/nano13192671 - 29 Sep 2023
Cited by 21 | Viewed by 845
Abstract
The phenomenon of nanofluid flows is intrinsically characterized by several scales and intricate physical processes [...] Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)

Research

Jump to: Editorial, Review

23 pages, 6199 KiB  
Article
Entropy Generation and Thermal Radiation Analysis of EMHD Jeffrey Nanofluid Flow: Applications in Solar Energy
by Bhupendra Kumar Sharma, Anup Kumar, Rishu Gandhi, Muhammad Mubashir Bhatti and Nidhish Kumar Mishra
Nanomaterials 2023, 13(3), 544; https://doi.org/10.3390/nano13030544 - 29 Jan 2023
Cited by 40 | Viewed by 2307
Abstract
This article examines the effects of entropy generation, heat transmission, and mass transfer on the flow of Jeffrey fluid under the influence of solar radiation in the presence of copper nanoparticles and gyrotactic microorganisms, with polyvinyl alcohol–water serving as the base fluid. The [...] Read more.
This article examines the effects of entropy generation, heat transmission, and mass transfer on the flow of Jeffrey fluid under the influence of solar radiation in the presence of copper nanoparticles and gyrotactic microorganisms, with polyvinyl alcohol–water serving as the base fluid. The impact of source terms such as Joule heating, viscous dissipation, and the exponential heat source is analyzed via a nonlinear elongating surface of nonuniform thickness. The development of an efficient numerical model describing the flow and thermal characteristics of a parabolic trough solar collector (PTSC) installed on a solar plate is underway as the use of solar plates in various devices continues to increase. Governing PDEs are first converted into ODEs using a suitable similarity transformation. The resulting higher-order coupled ODEs are converted into a system of first-order ODEs and then solved using the RK 4th-order method with shooting technique. The remarkable impacts of pertinent parameters such as Deborah number, magnetic field parameter, electric field parameter, Grashof number, solutal Grashof number, Prandtl number, Eckert number, exponential heat source parameter, Lewis number, chemical reaction parameter, bioconvection Lewis number, and Peclet number associated with the flow properties are discussed graphically. The increase in the radiation parameter and volume fraction of the nanoparticles enhances the temperature profile. The Bejan number and entropy generation rate increase with the rise in diffusion parameter and bioconvection diffusion parameter. The novelty of the present work is analyzing the entropy generation and solar radiation effects in the presence of motile gyrotactic microorganisms and copper nanoparticles with polyvinyl alcohol–water as the base fluid under the influence of the source terms, such as viscous dissipation, Ohmic heating, exponential heat source, and chemical reaction of the electromagnetohydrodynamic (EMHD) Jeffrey fluid flow. The non-Newtonian nanofluids have proven their great potential for heat transfer processes, which have various applications in cooling microchips, solar energy systems, and thermal energy technologies. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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15 pages, 4627 KiB  
Article
Comparative Analysis of LiMPO4 (M = Fe, Co, Cr, Mn, V) as Cathode Materials for Lithium-Ion Battery Applications—A First-Principle-Based Theoretical Approach
by Sayan Kanungo, Ankur Bhattacharjee, Naresh Bahadursha and Aritra Ghosh
Nanomaterials 2022, 12(19), 3266; https://doi.org/10.3390/nano12193266 - 20 Sep 2022
Cited by 14 | Viewed by 2559
Abstract
The rapidly increasing demand for energy storage has been consistently driving the exploration of different materials for Li-ion batteries, where the olivine lithium-metal phosphates (LiMPO4) are considered one of the most potential candidates for cathode-electrode design. In this context, the work [...] Read more.
The rapidly increasing demand for energy storage has been consistently driving the exploration of different materials for Li-ion batteries, where the olivine lithium-metal phosphates (LiMPO4) are considered one of the most potential candidates for cathode-electrode design. In this context, the work presents an extensive comparative theoretical study of the electrochemical and electrical properties of iron (Fe)-, cobalt (Co)-, manganese (Mn)-, chromium (Cr)-, and vanadium (V)-based LiMPO4 materials for cathode design in lithium (Li)-ion battery applications, using the density-functional-theory (DFT)-based first-principle-calculation approach. The work emphasized different material and performance aspects of the cathode design, including the cohesive energy of the material, Li-intercalation energy in olivine structure, and intrinsic diffusion coefficient across the Li channel, as well as equilibrium potential and open-circuit potential at different charge-states of Li-ion batteries. The results indicate the specification of the metal atom significantly influences the Li diffusion across the olivine structure and the overall energetics of different LiMPO4. In this context, a clear correlation between the structural and electrochemical properties has been demonstrated in different LiMPO4. The key findings offer significant theoretical and design-level insight for estimating the performance of studied LiMPO4-based Li-ion batteries while interfacing with different application areas. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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22 pages, 7837 KiB  
Article
Biochar-Mediated Zirconium Ferrite Nanocomposites for Tartrazine Dye Removal from Textile Wastewater
by Shazia Perveen, Raziya Nadeem, Farhat Nosheen, Muhammad Imran Asjad, Jan Awrejcewicz and Tauseef Anwar
Nanomaterials 2022, 12(16), 2828; https://doi.org/10.3390/nano12162828 - 17 Aug 2022
Cited by 10 | Viewed by 1877
Abstract
To meet the current challenges concerning the removal of dyes from wastewater, an environmentally friendly and efficient treatment technology is urgently needed. The recalcitrant, noxious, carcinogenic and mutagenic compound dyes are a threat to ecology and its removal from textile wastewater is challenge [...] Read more.
To meet the current challenges concerning the removal of dyes from wastewater, an environmentally friendly and efficient treatment technology is urgently needed. The recalcitrant, noxious, carcinogenic and mutagenic compound dyes are a threat to ecology and its removal from textile wastewater is challenge in the current world. Herein, biochar-mediated zirconium ferrite nanocomposites (BC-ZrFe2O5 NCs) were fabricated with wheat straw-derived biochar and applied for the adsorptive elimination of Tartrazine dye from textile wastewater. The optical and structural properties of synthesized BC-ZrFe2O5 NCs were characterized via UV/Vis spectroscopy, Fourier transform Infra-red (FTIR), X-Ray diffraction (XRD), Energy dispersive R-Ray (EDX) and Scanning electron microscopy (SEM). The batch modes experiments were executed to explore sorption capacity of BC-ZrFe2O5 NCs at varying operative conditions, i.e., pH, temperature, contact time, initial dye concentrations and adsorbent dose. BC-ZrFe2O5 NCs exhibited the highest sorption efficiency among all adsorbents (wheat straw biomass (WSBM), wheat straw biochar (WSBC) and BC-ZrFe2O5 NCs), having an adsorption capacity of (mg g−1) 53.64 ± 0.23, 79.49 ± 0.21 and 89.22 ± 0.31, respectively, for Tartrazine dye at optimum conditions of environmental variables: pH 2, dose rate 0.05 g, temperature 303 K, time of contact 360 min and concentration 100 mg L−1. For the optimization of process variables, response surface methodology (RSM) was employed. In order to study the kinetics and the mechanism of the adsorption process, kinetic and equilibrium mathematical models were used, and results revealed 2nd order kinetics and a multilayer chemisorption mechanism due to complexation of hydroxyl, Fe and Zr with dyes functional groups. The nanocomposites were also recovered in five cycles without significant loss (89 to 63%) in adsorption efficacy. This research work provides insight into the fabrication of nanoadsorbents for the efficient adsorption of Tartrazine dye, which can also be employed for practical engineering applications on an industrial scale as efficient and cost effective materials. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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16 pages, 2448 KiB  
Article
Hybrid Plasma–Liquid Functionalisation for the Enhanced Stability of CNT Nanofluids for Application in Solar Energy Conversion
by Ruairi J. McGlynn, Hussein S. Moghaieb, Paul Brunet, Supriya Chakrabarti, Paul Maguire and Davide Mariotti
Nanomaterials 2022, 12(15), 2705; https://doi.org/10.3390/nano12152705 - 06 Aug 2022
Cited by 2 | Viewed by 1703
Abstract
Macroscopic ribbon-like assemblies of carbon nanotubes (CNTs) are functionalised using a simple direct-current-based plasma–liquid system, with oxygen and nitrogen functional groups being added. These modifications have been shown to reduce the contact angle of the ribbons, with the greatest reduction being from 84° [...] Read more.
Macroscopic ribbon-like assemblies of carbon nanotubes (CNTs) are functionalised using a simple direct-current-based plasma–liquid system, with oxygen and nitrogen functional groups being added. These modifications have been shown to reduce the contact angle of the ribbons, with the greatest reduction being from 84° to 35°. The ability to improve the wettability of the CNTs is of paramount importance for producing nanofluids, with relevance for a number of applications. Here, in particular, we investigate the efficacy of these samples as nanofluid additives for solar–thermal harvesting. Surface treatments by plasma-induced non-equilibrium electrochemistry are shown to enhance the stability of the nanofluids, allowing for full redispersion under simulated operating conditions. Furthermore, the enhanced dispersibility results in both a larger absorption coefficient and an improved thermal profile under solar simulation. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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19 pages, 5963 KiB  
Article
Rheological Modeling of Metallic Oxide Nanoparticles Containing Non-Newtonian Nanofluids and Potential Investigation of Heat and Mass Flow Characteristics
by Muhammad Rizwan, Mohsan Hassan, Oluwole Daniel Makinde, Muhammad Mubashir Bhatti and Marin Marin
Nanomaterials 2022, 12(7), 1237; https://doi.org/10.3390/nano12071237 - 06 Apr 2022
Cited by 13 | Viewed by 1784
Abstract
Nanofluids have great potential due to their improved properties that make them useful for addressing various industrial and engineering problems. In order to use nanofluids on an industrial scale, it is first important to discuss their rheological behavior in relation to heat transfer [...] Read more.
Nanofluids have great potential due to their improved properties that make them useful for addressing various industrial and engineering problems. In order to use nanofluids on an industrial scale, it is first important to discuss their rheological behavior in relation to heat transfer aspects. In the current study, the flow characteristics of nanofluids are discussed using a mathematical model that is developed by fundamental laws and experimental data. The data are collected in the form of viscosity versus shear rate for different homogeneous ethylene glycol- (EG) based nanofluids, which are synthesized by dispersing 5–20% nanoparticle concentrations of SiO2, MgO, and TiO2 with diameters of (20–30 nm, 60–70 nm), (20 nm, 40 nm), and (30 nm, 50 nm), respectively. The data are fitted into a rheological power-law model and further used to govern equations of a physical problem. The problem is simplified into ordinary differential equations by using a boundary layer and similarity transformations and then solved through the numerical Runge–Kutta (RK) method. The obtained results in the form of velocity and temperature profiles at different nanoparticle concentrations and diameters are displayed graphically for discussion. Furthermore, displacement and momentum thicknesses are computed numerically to explain boundary-layer growth. The results show that the velocity profile is reduced and the temperature profile is raised by increasing the nanoparticle concentration. Conversely, the velocity profile is increased and the temperature profile is decreased by increasing the nanoparticle diameter. The results of the present investigation regarding heat and mass flow behavior will help engineers design equipment and improve the efficacy and economy of the overall process in the industry. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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13 pages, 3388 KiB  
Article
Analytical Investigation of the Time-Dependent Stagnation Point Flow of a CNT Nanofluid over a Stretching Surface
by Ali Rehman, Anwar Saeed, Zabidin Salleh, Rashid Jan and Poom Kumam
Nanomaterials 2022, 12(7), 1108; https://doi.org/10.3390/nano12071108 - 28 Mar 2022
Cited by 6 | Viewed by 1774
Abstract
The heat transfer ratio has an important role in industry and the engineering sector; the heat transfer ratios of CNT nanofluids are high compared to other nanofluids. This paper examines the analytical investigation of the time-dependent stagnation point flow of a CNT nanofluid [...] Read more.
The heat transfer ratio has an important role in industry and the engineering sector; the heat transfer ratios of CNT nanofluids are high compared to other nanofluids. This paper examines the analytical investigation of the time-dependent stagnation point flow of a CNT nanofluid over a stretching surface. For the investigation of the various physical restrictions, single and multi-walled carbon nanotubes (SWCNTs, MWCNTs) were used and compared. The defined similarity transformation was used, to reduce the given nonlinear partial differential equations (PDEs) to nonlinear ordinary differential equations (ODEs). The model nonlinear ordinary differential equations were solved, with an approximate analytical (OHAM) optimal homotopy asymptotic method being used for the model problem. The impact of different parameters such as magnetic field parameter, unsteady parameter, dimensionless nanoparticles volume friction, Prandtl number, and Eckert number are interpreted using graphs, in the form of the velocity and temperature profile. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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21 pages, 7363 KiB  
Article
Computational Framework of Magnetized MgO–Ni/Water-Based Stagnation Nanoflow Past an Elastic Stretching Surface: Application in Solar Energy Coatings
by Muhammad Mubashir Bhatti, Osman Anwar Bég and Sara I. Abdelsalam
Nanomaterials 2022, 12(7), 1049; https://doi.org/10.3390/nano12071049 - 23 Mar 2022
Cited by 91 | Viewed by 2549
Abstract
In this article, motivated by novel nanofluid solar energy coating systems, a mathematical model of hybrid magnesium oxide (MgO) and nickel (Ni) nanofluid magnetohydrodynamic (MHD) stagnation point flow impinging on a porous elastic stretching surface in a porous medium is developed. The hybrid [...] Read more.
In this article, motivated by novel nanofluid solar energy coating systems, a mathematical model of hybrid magnesium oxide (MgO) and nickel (Ni) nanofluid magnetohydrodynamic (MHD) stagnation point flow impinging on a porous elastic stretching surface in a porous medium is developed. The hybrid nanofluid is electrically conducted, and a magnetic Reynolds number is sufficiently large enough to invoke an induced magnetic field. A Darcy model is adopted for the isotropic, homogenous porous medium. The boundary conditions account for the impacts of the velocity slip and thermal slip. Heat generation (source)/absorption (sink) and also viscous dissipation effects are included. The mathematical formulation has been performed with the help of similarity variables, and the resulting coupled nonlinear dimensionless ordinary differential equations have been solved numerically with the help of the shooting method. In order to test the validity of the current results and the convergence of the solutions, a numerical comparison with previously published results is included. Numerical results are plotted for the effect of emerging parameters on velocity, temperature, magnetic induction, skin friction, and Nusselt number. With an increment in nanoparticle volume fraction of both MgO and Ni nanoparticles, the temperature and thermal boundary layer thickness of the nanofluid are elevated. An increase in the porous medium parameter (Darcy number), velocity slip, and thermal Grashof number all enhance the induced magnetic field. Initial increments in the nanoparticle volume fraction for both MgO and Ni suppress the magnetic induction near the wall, although, subsequently, when further from the wall, this effect is reversed. Temperature is enhanced with heat generation, whereas it is depleted with heat absorption and thermal slip effects. Overall, excellent thermal enhancement is achieved by the hybrid nanofluid. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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18 pages, 3203 KiB  
Article
Computational Analysis of the Morphological Aspects of Triadic Hybridized Magnetic Nanoparticles Suspended in Liquid Streamed in Coaxially Swirled Disks
by Zubair Akbar Qureshi, Sardar Bilal, Imtiaz Ali Shah, Ali Akgül, Rabab Jarrar, Hussein Shanak and Jihad Asad
Nanomaterials 2022, 12(4), 671; https://doi.org/10.3390/nano12040671 - 17 Feb 2022
Cited by 11 | Viewed by 1473
Abstract
Currently, pagination clearly explains the increase in the thermophysical attributes of viscous hybrid nanofluid flow by varying morphological aspects of inducted triadic magnetic nanoparticles between two coaxially rotating disks. Copper metallic nanoparticles are inserted with three different types of metallic oxide nanoparticles: Al [...] Read more.
Currently, pagination clearly explains the increase in the thermophysical attributes of viscous hybrid nanofluid flow by varying morphological aspects of inducted triadic magnetic nanoparticles between two coaxially rotating disks. Copper metallic nanoparticles are inserted with three different types of metallic oxide nanoparticles: Al2O3, Ti2O, and Fe3O4. Single-phase simulation has been designed for the triadic hybrid nanofluids flow. The achieved expressions are transmuted by the obliging transformation technique because of dimensionless ordinary differential equations (ODEs). Runge–Kutta in collaboration with shooting procedure are implemented to achieve the solution of ODEs. The consequences of pertinent variables on associated distributions and related quantities of physical interest are elaborated in detail. It is inferred from the analysis that Cu-Al2O3 metallic type hybrid nanofluids flow shows significant results as compared with the other hybrid nanoparticles. The injection phenomenon on hybrid nanofluids gives remarkable results regarding shear stress and heat flux with the induction of hybridized metallic nanoparticles. Shape and size factors have also been applied to physical quantities. The morphology of any hybrid nanoparticles is directly proportional to the thermal conductance of nanofluids. Peclet number has a significant effect on the temperature profile. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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12 pages, 7298 KiB  
Article
Higher-Dimensional Fractional Order Modelling for Plasma Particles with Partial Slip Boundaries: A Numerical Study
by Tamour Zubair, Muhammad Imran Asjad, Muhammad Usman and Jan Awrejcewicz
Nanomaterials 2021, 11(11), 2884; https://doi.org/10.3390/nano11112884 - 28 Oct 2021
Cited by 1 | Viewed by 1080
Abstract
We integrate fractional calculus and plasma modelling concepts with specific geometry in this article, and further formulate a higher dimensional time-fractional Vlasov Maxwell system. Additionally, we develop a quick, efficient, robust, and accurate numerical approach for temporal variables and filtered Gegenbauer polynomials based [...] Read more.
We integrate fractional calculus and plasma modelling concepts with specific geometry in this article, and further formulate a higher dimensional time-fractional Vlasov Maxwell system. Additionally, we develop a quick, efficient, robust, and accurate numerical approach for temporal variables and filtered Gegenbauer polynomials based on finite difference and spectral approximations, respectively. To analyze the numerical findings, two types of boundary conditions are used: Dirichlet and partial slip. Particular methodology is used to demonstrate the proposed scheme’s numerical convergence. A detailed analysis of the proposed model with plotted figures is also included in the paper. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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Review

Jump to: Editorial, Research

22 pages, 3382 KiB  
Review
A Review on Recent Progress in Preparation of Medium-Temperature Solar-Thermal Nanofluids with Stable Dispersion
by Ting Hu, Jingyi Zhang, Ji Xia, Xiaoxiang Li, Peng Tao and Tao Deng
Nanomaterials 2023, 13(8), 1399; https://doi.org/10.3390/nano13081399 - 18 Apr 2023
Cited by 4 | Viewed by 1240
Abstract
Direct absorption of sunlight and conversion into heat by uniformly dispersed photothermal nanofluids has emerged as a facile way to efficiently harness abundant renewable solar-thermal energy for a variety of heating-related applications. As the key component of the direct absorption solar collectors, solar-thermal [...] Read more.
Direct absorption of sunlight and conversion into heat by uniformly dispersed photothermal nanofluids has emerged as a facile way to efficiently harness abundant renewable solar-thermal energy for a variety of heating-related applications. As the key component of the direct absorption solar collectors, solar-thermal nanofluids, however, generally suffer from poor dispersion and tend to aggregate, and the aggregation and precipitation tendency becomes even stronger at elevated temperatures. In this review, we overview recent research efforts and progresses in preparing solar-thermal nanofluids that can be stably and homogeneously dispersed under medium temperatures. We provide detailed description on the dispersion challenges and the governing dispersion mechanisms, and introduce representative dispersion strategies that are applicable to ethylene glycol, oil, ionic liquid, and molten salt-based medium-temperature solar-thermal nanofluids. The applicability and advantages of four categories of stabilization strategies including hydrogen bonding, electrostatic stabilization, steric stabilization, and self-dispersion stabilization in improving the dispersion stability of different type of thermal storage fluids are discussed. Among them, recently emerged self-dispersible nanofluids hold the potential for practical medium-temperature direct absorption solar-thermal energy harvesting. In the end, the exciting research opportunities, on-going research need and possible future research directions are also discussed. It is anticipated that the overview of recent progress in improving dispersion stability of medium-temperature solar-thermal nanofluids can not only stimulate exploration of direct absorption solar-thermal energy harvesting applications, but also provide a promising means to solve the fundamental limiting issue for general nanofluid technologies. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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31 pages, 6460 KiB  
Review
Nanofluids for Direct-Absorption Solar Collectors—DASCs: A Review on Recent Progress and Future Perspectives
by Hussein Sayed Moghaieb, Vincenzo Amendola, Sameh Khalil, Supriya Chakrabarti, Paul Maguire and Davide Mariotti
Nanomaterials 2023, 13(7), 1232; https://doi.org/10.3390/nano13071232 - 30 Mar 2023
Cited by 5 | Viewed by 1870
Abstract
Owing to their superior optical and thermal properties over conventional fluids, nanofluids represent an innovative approach for use as working fluids in direct-absorption solar collectors for efficient solar-to-thermal energy conversion. The application of nanofluids in direct-absorption solar collectors demands high-performance solar thermal nanofluids [...] Read more.
Owing to their superior optical and thermal properties over conventional fluids, nanofluids represent an innovative approach for use as working fluids in direct-absorption solar collectors for efficient solar-to-thermal energy conversion. The application of nanofluids in direct-absorption solar collectors demands high-performance solar thermal nanofluids that exhibit exceptional physical and chemical stability over long periods and under a variety of operating, fluid dynamics, and temperature conditions. In this review, we discuss recent developments in the field of nanofluids utilized in direct-absorption solar collectors in terms of their preparation techniques, optical behaviours, solar thermal energy conversion performance, as well as their physical and thermal stability, along with the experimental setups and calculation approaches used. We also highlight the challenges associated with the practical implementation of nanofluid-based direct-absorption solar collectors and offer suggestions and an outlook for the future. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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24 pages, 2796 KiB  
Review
A Comprehensive Review of Nanofluid Heat Transfer in Porous Media
by Hossam A. Nabwey, Taher Armaghani, Behzad Azizimehr, Ahmed M. Rashad and Ali J. Chamkha
Nanomaterials 2023, 13(5), 937; https://doi.org/10.3390/nano13050937 - 04 Mar 2023
Cited by 8 | Viewed by 2420
Abstract
In the present paper, recent advances in the application of nanofluids in heat transfer in porous materials are reviewed. Efforts have been made to take a positive step in this field by scrutinizing the top papers published between 2018 and 2020. For that [...] Read more.
In the present paper, recent advances in the application of nanofluids in heat transfer in porous materials are reviewed. Efforts have been made to take a positive step in this field by scrutinizing the top papers published between 2018 and 2020. For that purpose, the various analytical methods used to describe the flow and heat transfer in different types of porous media are first thoroughly reviewed. In addition, the various models used to model nanofluids are described in detail. After reviewing these analysis methods, papers concerned with the natural convection heat transfer of nanofluids in porous media are evaluated first, followed by papers on the subject of forced convection heat transfer. Finally, we discuss articles related to mixed convection. Statistical results from the reviewed research regarding the representation of various parameters, such as the nanofluid type and the flow domain geometry, are analyzed, and directions for future research are finally suggested. The results reveal some precious facts. For instance, a change in the height of the solid and porous medium results in a change in the flow regime within the chamber; as a dimensionless permeability, the effect of Darcy’s number on heat transfer is direct; and the effect of the porosity coefficient has a direct relationship with heat transfer: when the porosity coefficient is increased or decreased, the heat transfer will also increase or decrease. Additionally, a comprehensive review of nanofluid heat transfer in porous media and the relevant statical analysis are presented for the first time. The results show that Al2O3 nanoparticles in a base fluid of water with a proportion of 33.9% have the highest representation in the papers. Regarding the geometries studied, a square geometry accounted for 54% of the studies. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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59 pages, 3141 KiB  
Review
Progress and Recent Trends in the Application of Nanoparticles as Low Carbon Fuel Additives—A State of the Art Review
by Jeffrey Dankwa Ampah, Abdulfatah Abdu Yusuf, Ephraim Bonah Agyekum, Sandylove Afrane, Chao Jin, Haifeng Liu, Islam Md Rizwanul Fattah, Pau Loke Show, Mokhtar Shouran, Monier Habil and Salah Kamel
Nanomaterials 2022, 12(9), 1515; https://doi.org/10.3390/nano12091515 - 29 Apr 2022
Cited by 15 | Viewed by 2901
Abstract
The first part of the current review highlights the evolutionary nuances and research hotspots in the field of nanoparticles in low carbon fuels. Our findings reveal that contribution to the field is largely driven by researchers from Asia, mainly India. Of the three [...] Read more.
The first part of the current review highlights the evolutionary nuances and research hotspots in the field of nanoparticles in low carbon fuels. Our findings reveal that contribution to the field is largely driven by researchers from Asia, mainly India. Of the three biofuels under review, biodiesel seems to be well studied and developed, whereas studies regarding vegetable oils and alcohols remain relatively scarce. The second part also reviews the application of nanoparticles in biodiesel/vegetable oil/alcohol-based fuels holistically, emphasizing fuel properties and engine characteristics. The current review reveals that the overall characteristics of the low carbon fuel–diesel blends improve under the influence of nanoparticles during combustion in diesel engines. The most important aspect of nanoparticles is that they act as an oxygen buffer that provides additional oxygen molecules in the combustion chamber, promoting complete combustion and lowering unburnt emissions. Moreover, the nanoparticles used for these purposes exhibit excellent catalytic behaviour as a result of their high surface area-to-volume ratio—this leads to a reduction in exhaust pollutants and ensures an efficient and complete combustion. Beyond energy-based indicators, the exergy, economic, environmental, and sustainability aspects of the blends in diesel engines are discussed. It is observed that the performance of the diesel engine fuelled with low carbon fuels according to the second law of efficiency improves under the influence of the nano-additives. Our final part shows that despite the benefits of nanoparticles, humans and animals are under serious threats from the highly toxic nature of nanoparticles. Full article
(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)
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