The importance of studying photovoltaic thermal (PVT) systems is underscored by their potential to harness both solar thermal and photovoltaic energy simultaneously, making them a promising avenue for sustainable power generation. The integration of a PVT system allows for enhanced energy conversion and utilization of available resources. In the context of the broader field of renewable energy, understanding and optimizing PVT systems contribute to the development of efficient and environmentally friendly power generation solutions. The introduction of CuO nanoparticles proves beneficial, contributing to an overall improvement in system performance. Throughout this exploration, the aim is to provide insights into the intricate dynamics of PVT systems under varying conditions, emphasizing the impact of key parameters on system efficiency and performance. Examining PVT systems, this study focuses on a rectangular duct equipped with a turbulator featuring rectangular cuts. The simulation considers the flow of CuO-H2O within the channel and accounts for pure conduction within the layers, employing the finite volume method with a validation test for accuracy. The mesh size has been optimized for computational efficiency. In this context, the study investigates variations in cell temperature (TPV) and efficiency components (electrical (ηPV), thermal (ηth), overall (ηPVT)) concerning key variables: wind speed (Vw (0.4, 1, 1.4 m/s)), incident irradiation (G (730, 830, 930 W/m2)), inlet velocity (0.08, 0.1, 0.12 m/s), volume fraction of CuO (ϕ = 0, 0.018). Introducing the turbulator improves TPV uniformity by about 20.43%. With increased incident irradiation in the presence of the turbulator, ηPV, ηth, and ηPVT values enhance by approximately 1.02%, 8.18%, and 4.99%, respectively. Specifically, at G = 930 W/m2, the turbulator installation leads to a 4.35% increase in ηPVT. However, certain variables demonstrate contrasting effects. Increased wind speed results in a 3.63% decrease in ηPVT for tubes equipped with a turbulator. Conversely, intensifying the inlet velocity leads to an augmentation of ηPVT by around 3.19%, coupled with a notable 16.34% improvement in the uniformity of TPV.
In this paper, influence of an external magnetic field on ferrofluid flow and heat transfer in a semi annulus enclosure with sinusoidal hot wall is investigated. The governing equations which are derived by considering the both effects of FHD (Ferrohydrodynamic) and MHD (Magnetohydrodynamic) are solved via CVFEM (Control Volume based Finite Element Method). The effects of Rayleigh number, nanoparticle volume fraction, Magnetic number arising from FHD and Hartmann number arising from MHD on the flow and heat transfer characteristics have been examined. Results show that Nusselt number increases with augment of Rayleigh number and nanoparticle volume fraction but it decreases with increase of Hartmann number. Magnetic number has different effect on Nusselt number corresponding to Rayleigh number. Also it can be found that for low Rayleigh number, enhancement in heat transfer is an increasing function of Hartmann number and decreasing function of Magnetic number while opposite trend is observed for high Rayleigh number.
This research investigates the enhancement of photovoltaic (PV) solar panel performance through the application of a paraffin-based spectral splitter. The study aims to improve electrical efficiency and thermal management while mitigating dust deposition effects. A paraffin (RT25) spectral filter is placed above the glass layer of the PV panel, coupled with a ZnO-water nanofluid-filled mini-channel for cooling at the panel's bottom. Optical properties, derived from previous experimental work, are incorporated into simulations. Self-cleaning SiO2 nanoparticle coating is proposed to improve transmissivity of upper glass. Fresnel lens is used to intensify irradiation at two concentration ratios (CR). Three-dimensional simulations integrating source terms based on optical analysis were conducted. Key findings include a decrease in panel temperature (TPV) due to partial irradiation absorption by the spectral filter, leading to lower heat flux to the cooling zone. The spectral filter increased electrical efficiency (ηPV) by 11.28 % and 38.63 % at 20 and 40 min, respectively. The presence of the filter and coatings significantly improved temperature uniformity, with improvements of 68.77 % and 50.35 % at 10 and 40 min, respectively. Increasing CR resulted in a 2.95 % and 83.31 % rise in filter temperature (TPCM) and liquid fraction (LF), with a minor 1.56 % decrease in efficiency. At CR = 2, in the presence of the spectral filter, ηPV decreases by 38.62 %, accounting for dust effects, while it increases by 21.83 % with adding coating. The research highlights the potential of spectral filters and innovative coatings to enhance PV panel performance, offering a novel approach to sustainable and efficient solar energy systems.
No abstract is provided for this article.
In this paper, influence of external magnetic field and thermal radiation on heat transfer intensification of nanofluid in a porous curved enclosure is simulated. Magnetic field and shape factor effects on nanofluid properties are taken into account. Final equations are obtained by means of vorticity stream function formulation and they are solved via Control volume based finite element method. Isotherms and streamlines are shown for various values of Darcy number, Fe3O4-water nanofluid volume fraction, radiation parameter, Hartmann number and Rayleigh number. Results indicate that maximum Nusselt number is obtained for Platelet shaped nanoparticles. Heat transfer rate augments with rise of permeability of porous media and Rayleigh number and opposite trend is observed for Hartmann number. Besides, it can be found that velocity of nanofluid decreases with increase of Lorentz forces.
Purpose This paper aims to investigate non-Darcy magnetohydrodynamic nanofluid flow in a uniformly porous medium. It is assumed that viscosity of nanofluid (Fe 3 O 4 -water) is a function of external magnetic field. Roles of Darcy number, inclination angle, volume fraction of nanofluid, Hartmann and Rayleigh numbers are demonstrated graphically. Design/methodology/approach The problem is modeled, and simulation has been done by means of control volume base finite element method. Findings Results proved that Nusselt number enhances with augment of buoyancy forces and Darcy number while it decreases with the increase of Lorentz forces. Isotherms become denser near the inner cylinder with increase of inclination angle and the Darcy number. Originality/value As per the authors’ knowledge, this problem is new and not been published before.
The current article investigates the impact of using fins and nano sized materials on performance of discharging system. Various shapes for nanoparticle have been considered. Cold fluid flows in both inner and outer layers and middle layer is full of PCM. To make a careful choice of designing heat storage based on uniform solidification, two factor has been examined; length of fins and shape factor. Temperature and solid fraction distributions were reported at various time steps. The homogeneous model for nanofluid has been extended by incorporating various shapes of CuO nanoparticles. The mathematical model has been offered in the form of PDE's, which were solved using Galerkin FEM. It can be observed that the employing nanofluid augments the discharging rate and best performance is obtained for platelet shape.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of The authors have plagiarized part of a paper that had already appeared in Applied Mathematical Modelling 36 (2012) 1806–1820 https://doi.org/10.1016/j.apm.2011.09.010. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
Three dimensional problems reflect more imperative understanding to real world issues in comparison to two dimensional problems. Keeping this fact in mind, a mathematical model is designed to deliberate the 3D magnetohydrodynamic couple stress nanofluid flow with joule heating and viscous dissipation effects past an exponential stretched surface. The analysis is performed keeping in mind the physical effects of Brownian motion and thermophoresis combined with convective heat condition. This paper also distinctly introduces a more realistic boundary constraint for nanoliquid flow model. For instance, zero mass flux condition has been instituted for the first time for 3D couple stress nanofluid model as far as the exponential stretched surface is concerned. Self-similar transformations are engaged to obtain a system of ordinary differential equations possessing high nonlinearity from the system of boundary layer partial differential equations. Analytic solution is constructed in the form of series using Homotopy Analysis Method (HAM). Numerically calculated values of Skin friction and local Nusselt number are also given with suitable analysis. Moreover, the influences of sundry parameters on velocity distribution, and heat and mass transfer rates are deliberated and depicted through relevant graphs. The results obtained clearly show that the Biot number and Hartmann number possess increasing effect on temperature distribution. To authenticate our obtained results, a comparison in limiting case is also given.
The astounding physiognomies of carbon nanotubes such as lightweight, mechanical stability, excellent thermal and electrical conductivities, and physicochemical compatibility make them perfect material for electrochemical gadgets. Having such amazing characteristics in mind our intention is to provide a numerical solution of Casson nanofluid flow containing melting heat transfer past a swirling cylinder. Analysis of multi-wall carbon nanotubes (MWCNTs) with water as a base fluid is performed. Effects of entropy generation, magnetohydrodynamics, and heat generation/absorption are also contemplated. The proposed physical model is erected and through feasible transformations, the obtained coupled nonlinear system of ODEs is solved via bvp4c function of MATLAB software numerically. The impacts of Casson nanofluid comprises of MWCNTs on skin friction, entropy generation coefficient and heat transfer rate are analyzed. Graphs of physical parameters of interest, Casson parameter (0≤β≤2), magnetic parameter (0≤M≤6), nanoparticle volume fraction (0≤ϕ≤0.3), melting parameter (0.1≤M*≤2.0), dimensionless temperature difference (0≤α≤0.3), Brinkman number (0.7≤Br≤2.0), versus swirling velocity, temperature and entropy optimization are also illustrated and discussed in detail. Tabulated numerical values of skin friction and heat transfer rate with requisite discussion are also a part this analysis. It is finally summarized that entropy optimization is an escalating function of magnetic parameter.
Magnetic nanofluid hydrothermal analysis over a plate is studied that includes consideration of thermal radiation. The Runge–Kutta (RK4) method is utilized to get solution of ODEs which are obtained from similarity solution. In considering the impacts of Brownian motion, we applied Koo–Kleinstreuer–Li correlation to simulate the properties of CuO–water. The influence is discussed of important parameters such as the temperature index, magnetic, radiation, and velocity ratio parameters and volume fraction of nanoparticle on hydrothermal behavior. Results illustrate that the coefficient of skin friction enhances with enhancing magnetic parameter while reduces with enhancing velocity ratio parameter. Also the Nusselt number was found to directly depend on the velocity ratio and temperature index parameters but has an inverse dependence on the magnetic and radiation parameters.
No abstract is provided for this article.
In current work, turbulent flow of H2O based nanomaterial flow containing copper oxide inside a pipe fitted with new swirl flow generator was examined. Outputs were examined to find the impact of width tape for the Reynolds number in turbulent regime. In addition, correlations were derived for predicting component of irreversibility. Outcome show that viscous loss has direct relationship with pumping power. Thus, increasing inlet velocity makes the differential pressure to augment. Owing to higher velocity gradient, S gen,f augments with increasing width. Using turbulator with greater b leads to generate stronger turbulence intensity.
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
The three-dimensional problem of steady fluid deposition on an inclined rotating disk is illustrated in this study. The governing non-linear partial differential equations are reduced to the nonlinear ordinary differential equations system by similarity transform. The analytical solution applied to solve this system is the Homotopy Perturbation Method (HPM). The velocity and temperature profiles are shown and the influence of Prandtl number and rotation ratio on the flow field and the Nusselt number are discussed in detail. The validity of our solutions is verified by the numerical results.
The performance of several heat transfer mechanisms, including solar energy sources, is being improved through optimization, which also effectively supports the most efficient feasible design. A numerical study has been done on a turbulator-enhanced flat plate solar collector (FPSC) while also introducing the utilization of a quad-lobed tube as a pioneering innovation in the system’s design. The incorporation of nanoparticles into the working fluid was implemented to enhance performance, with aluminum oxide particles selected for this purpose. Furthermore, assessing the second law and analyzing exergy generation was employed to discern irreversibility within the system. Optimization of both geometric and non-geometric elements has been accomplished through the integration of a multi-objective optimization (MOO) method with machine learning (ML). Random Forest (RF), LASSO Regression (LaR), and Support Vector Regression (SVR) are the machine learning models that were utilized in order to ascertain the correlations that exist between the system’s inputs and outputs. According to the findings, RF was found to be the most appropriate algorithm for capturing the impacts of parameter variations. This was demonstrated by the high coefficient of determination (R2) quantities that RF possessed, which were 0.95, 0.99, and 0.99 for friction factor (f), exergy loss (Xd ), and second law effectiveness ( η II ), respectively. However, the SVR and LaR algorithms showed significant deviations from the FPSC simulation results. The SVR algorithm achieved R2 values of 0.54 for f, 0.78 for Xd , and 0.84 for η II , while the LaR algorithm achieved R2 values of 0.65 for f, 0.99 for Xd , and 0.98 for η II . This research aims to find the optimal input parameters that minimize f and Xd while maximizing η II . Therefore, to determine the Pareto optimal solutions the non-dominated sorting genetic algorithm (NSGA-II) has been utilized. The result was an illustration of the Pareto set, which stands for a collection of optimal solutions. Every solution in this collection achieved the desiredbalance, obtaining the best outcomes without compromising any objectives.
