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While there are some hydrogen refueling stations (HRS) functioning in different parts of the world, their use is not widespread enough, primarily due to their expensive cost. Hydrogen compression is a main contributor to the capital and operation costs of the HRS. By improving H2 compression technology, it is possible to optimize the infrastructure for refueling with hydrogen in terms of cost and performance. The use of metal hydride hydrogen compressors (MHHCs), which have the potential to be inexpensive and have the ability to use waste heat and renewable energy sources for the H2 compression, is a promising solution to overcome this issue. The duration of the H2 compression cycle is nevertheless a serious challenge due to the metal hydride (MH) bed's low heat conductivity. As a heating technique to improve the performance of MHHCs, electromagnetic induction (EMI) is examined numerically for the first time in this work. The dynamic behavior of a two-stage MHHC with each MH reactor having an external heat exchanger and being ringed by a copper coil traversed by an alternating current is described by a two-dimensional mathematical model, which was established and successfully verified by the reference data. Numerical simulations were performed with the help of this model, and the findings showed that the EMI heating method is faster than the heat transfer fluid (HTF) heating technique. For instance, at a delivery temperature of 373 K and a supply pressure of 20 bar, it is possible to produce 106 NL H2 per kilogram of HPMH at a pressure of 97 bar with a 74 % shorter compression time than with the HTF heating technique.

This study investigates the optimal configuration of a Metal Hydride-based Solar Thermal Collector (MH-STC) by developing a transient 3D mathematical model to simulate three distinct configurations: C1, C2, and C3. These configurations differ in the placement of water pipes within the metal hydride bed C1 features pipes in the top region, C2 in the core zone, and C3 at the bottom. The performance of these configurations was rigorously compared based on hydrogen charge state, outlet water temperature, useful energy output, and thermal efficiency across varying water flow rates. Results reveal that configuration C1 achieves superior thermal performance during daytime operation, producing outlet temperatures up to 10 °C higher than the other configurations. Conversely, configuration C3 excels at nighttime heating, delivering water temperatures approximately 11.5 °C higher than C1. Furthermore, the analysis indicates that hydrogen desorption pressure significantly impacts outlet water temperature; for instance, increasing the pressure from 2.41 bar to 6 bar enhances the average outlet temperature of the C3 design by about 20 °C during the day and reduces it by approximately 15 °C at night. These findings highlight the critical need for optimizing solar collector designs to effectively meet the thermal demands of both daytime and nighttime applications.

The present study aims to assess the technical feasibility of a novel Metal Hydride-based Solar Thermal Collector (MH-STC) system. This system includes a flat-plate solar collector integrated with a metal hydride bed, a hydrogen compressor, a photovoltaic panel, a hydrogen tank, and a water storage tank. This system combines the principles of a conventional solar thermal collector with the energy storage capabilities of metal hydrides, enabling the storage of surplus thermal energy. The LaNi5 alloy was used as heat storage material. A 3D-mathematical model is established and a numerical code written in Fortran-90 is developed to simulate the dynamic behavior of the proposed solar thermal collector. It was shown that the developed 3D-model produces computational results that are consistent with experimental data. In addition, to check the accuracy of the mathematical model and numerical approach, the relative errors in the mass balance and energy balance were calculated and values of 0.054 % and 0.18 %, respectively, were obtained.The simulation results offer insights into the system's technical feasibility, revealing an overall efficiency of 90.6 %, the water temperature at the collector outlet can reach 357.3 K, and a water volume heated of 230.4 L under the considered operating conditions. Moreover, the results indicate that the proposed MH-STC system exhibits significant potential as a viable alternative for thermal storage in domestic hot water systems.

Since performance of thermal systems may depend on fluids’ thermal conductivities being utilized as coolants, improvement of thermal efficiencies of fluids having micro-structures and involving ternary hybrid nanomaterials may be highly valued. In fact, microrotation of ternary hybrid nanofluids (THNFs) in oblique incinerator-shaped chamber may find applications in industrial processes involving polymeric solutions and lubricants where they help in reduction of drag forces and act as better cooling agent. In view of this, the present study carries out thermal and second law dissection of micropolar THNF within an oblique incinerator-shaped chamber heated from bottom emplacing a roundish heater under a fixed heat flux. The THNF comprises of Al2O3, CNT and graphene as nanoparticles. The study reveals that streamlines and isotherms undergo prominent change due to inclination of the chamber. When Raleigh number and diameter of heater amplify streamlines, microrotations, and entropy generation intensify while average Bejan number whittles down. Average heat transfer rate ameliorates by 4.54 % and 2.17 % when total volume fraction augments from 1.5 % to 3 % and 3 %–4.5 %, respectively. Heat transfer rate reduces by 1.23 %, 0.48 %, 3.33 %, 5.24 %, 2.07 %, and 1.66 % when inclination angle increases from 0° to 90° with inclination angle step 15°.

In this research, a numerical simulation was undertaken to assess the effectiveness of an Evacuated tube solar collector (ETSC). The study explored the efficacy of merging a parabolic trough solar collector (PTSC) and copper fins into the U-tube ETSC design. Two types of fins, namely annular fins and disk-shaped fins, were evaluated. Additionally, the study aimed to analyze the influence of operational and geometric parameters, such as the heat transfer fluid (HTF) mass flow rate and the U-tube bend radius, on the performance of the U-tube ETSC. Furthermore, a comparative examination was carried out to identify the most suitable type of phase change material (PCM) for the U-tube ETSC. Finally, a comparative analysis was conducted to assess the performance of the U-tube ETSC in comparison to that of the coaxial tubes ETSC. The results clearly demonstrated that the integration of an PTSC, PCM, and disk-shaped fins substantially improved the overall performance of the ETSC in comparison to the conventional solar collector. This improvement led to a remarkable increase in energy efficiency, with an impressive gain of 42.94 %. The ETSC displayed remarkable performance, particularly at lower HTF mass flow rates and a reduced U-tube bend radius, achieving an average HTF temperature of 430 K. Additionally, among the tested PCMs, RT 82 emerged as the most suitable choice, providing an energy gain of 9.27 % in comparison with the case without PCM.

Thermal energy storage is necessary for concentrated solar power (CSP) plants; it's a useful technique for reducing fluctuations in the energy supply and aids in peak demand management. Therefore, in the present paper, a novel Hybrid Cascaded Thermal Energy Storage (Hyb-CTES) unit is proposed for use in solar-driven Rankine steam power plant. The concept of the heat storage hybridization examined in this study is to couple metal hydride-based thermochemical heat storage system with cascaded phase change materials-based latent heat storage. To assess the dynamic behavior of the Hyb-CTES unit, a two-dimensional transient model is established, and a computational code is developed. The mathematical model has been validated successfully by comparing it with experimental data and by verifying both the mass and energy balance. To choose the appropriate PCM's melting temperature, four approaches are proposed and tested. Numerical simulations were performed with the help of the developed computer code, and the findings demonstrated that the supplied hydrogen pressure and the temperatures of the metal hydride beds are the crucial parameters for determining the PCM melting temperature. In addition, it is found that the proposed cascaded PCMs configuration enhances the heat storage unit's thermal performance and can reduce the heat charge/discharge cycle duration by 19 %. Also, the results indicate that the new Hyb-CTES unit is a promising alternative for thermal storage for CSP plants.

This article explores the enhancement of thermal exchange in a dissipative Triple-nanoparticle (Al2O3+CuO+Cu) hybrid fluid over a stretchable wavy cylindrical surface with slip effect, incorporating Python bvp algorithm with artificial intelligence AI analysis of numerical results. The stochastic AI analysis gives the enhanced and optimized results with predictive modeling, incorporating randomness of influencing parameters and nonlinear turbulent behavior of model. The model has significant importance and application in noise reducing and drag reduction devices or structures. Moreover, the presented geometrical structure is useful in enhancing thermal conduction characteristic. The intricate interplay of constituent nanoparticles and their effect on complex heat transfer in drag optimization devices is the main focus of this study. Mathematical Model of PDEs of this flow problem is converted into system of ODEs by similarity transformations with introducing dimensionless parameters. Numerical solutions of the emerged system are obtained by Python bvp solver algorithm and graphical solutions by Python are presented. To expedite the solution process and enhance the accuracy of prediction, advanced AI algorithm, such as neural network and machine learning technique is adopted. Numerical dataset obtained from Python is embedded for further AI analysis by using Levenberg Marquardt Feed-forward Algorithm (LMFA) with 10 computing neurons and 4 output layers representing results for 4 parametric variations.A rise in the fluid flow speed is observed with higher of value yield stress or Newtonian-behavior i.e. of Casson parameter a1 and stretching parameter λ for the sheet, but shows a decline with enhancing turbulence s2. Temperature profile show a descending behavior with inclination of Eckert ratio Ec, and Prandtl ratio of momentum-thermal diffusivity.

The recent study concentrates on magnetohydrodynamics (MHD). Williamson fluid drifts over an exponentially extending sheet. The porous medium is also crucial to improving thermal efficiency. The flow pattern model considers the inspirations of Joule heating, heat generation, viscous dissipation, and thermal radiation. This study also comprises the activation energy, bio-convectional, and gyrotactic microorganism phenomena. Furthermore, the Brownian and thermophoresis effects of nanoparticles are taken into consideration. Using proper similarity transformation, PDEs of the impetus, temperature, concentricity, motility microbe density, and boundary constraints upgrade into a non-linearly ordinary differential equations (ODEs) mode. Using MATLAB, transformed non-dimensional ODEs are dealt with using shooting procedures and results of significant physical strictures using a built-in bvp4c solver. Finally, it is elaborated and briefly explored numerically and visually can find interesting physical strictures versus the velocity gradient, temperature gradient, solutal gradient of species, and microbes' gradient. Incorporating microorganisms and nanoparticles into Williamson fluids can create novel materials with tailored properties for diverse applications. However, it's crucial to consider stability, biocompatibility, and environmental impact when designing these advanced fluid systems.

This study aims to determine which thermal energy storage (TES) system is most suited for a concentrated solar power (CSP) plant. The question is which the best TES system, whether utilizing a single metal hydride or employing dual metal hydrides with or without reaction heat recovery via phase change material (PCM). The authors noted that no studies have been conducted to address this question thus far. Consequently, the primary aim of this paper is to compare three different TES systems in order to ascertain the viability, efficacy, and performance of the appropriate TES system. The examined TES systems included: (i) TES system 1, based on a single metal hydride tank coupled to a hydrogen tank through an H2 compressor; (ii) TES system 2, based on paired metal hydride tanks without recovering reaction heat; and (iii) TES system 3, based on paired metal hydride tanks incorporating a PCM for reaction heat recovery. To simulate and evaluate the performance of the three TES systems under various operating conditions, a mathematical model and computer program were created and successfully verified. By examining into their thermodynamic performance and practical viability, this study attempts to provide the strengths and limitations of each system. A comparison of the three TES systems' performance indicators indicates that the TES system 1 has the potential to provide a specific power output of 500.8 W/kg of alloy, which is 50.1 % and 76.4 % greater than the TES systems 2 and 3, respectively. With a volumetric storage capacity of 755 MJ/m3, the TES system 2 outperforms the other two TES systems by around 40 %. The TES system 3 can operate with 85.9 % energy storage efficiency. This efficiency is 30.3 % higher than that of the TES system 1 and 10.2 % higher than that of the system 2. Ultimately, the decision to choose either a TES system based on a single metal hydride or one involving paired metal hydrides is hinges on the specific requirements, limitations, and priorities of the TES system under consideration.

The current study represents a numerical investigation of the pin fin heat sink performance with different angles of wings. Five angles ranging from 0° to 90° have been represented and studied under inline and staggered arrangements of pin fins. Reynolds numbers range from 13,500 to 37500. The highest Nusselt number has been achieved by angle-0° with inline arrangement while it has been achieved by angle-22.5° with staggered arrangement. On the other hand, the maximum friction factor with both inline and staggered arrangements is represented by angle-0°. The highest thermohydraulic performance has been achieved by angle-22.5° for staggered arrangement while case without wings gives the highest performance for inline arrangement. Using wings in staggered arrangement shows significant effect on heat transfer performance. While it is not recommended to use wings in case of inline arrangement.

This article employs an artificial neural network technique to approximate the solution for the stagnation point flow with velocity and thermal slip effects, as well as radiative heat transfer. The PDE governing system is transformed into a set of coupled ordinary differential systems by incorporating similarity variables. The shooting method is used to obtain a dataset in Mathematica. To test the precision of the suggested model, the operations of training, testing, and validation are performed, and the results are compared to a reference dataset. The Levenberg-Marquardt backpropagation neural network model is utilized to solve the system of equations under different scenarios, and its output is evaluated using mean square error, state transition dynamics, error histograms analysis, and regression illustrations. The findings indicate that the neural network approach achieves a high level of accuracy when predicting thermal analysis. Moreover, the current Artificial Neural Network model has an advantage over other numerical techniques in that it can handle more intricate mathematical models while minimizing the resources required for problem-solving.

The current research looks into magnetohydrodynamics Casson nanofluid flow and suction/injection implications for a nonlinearly stretched interface. To improve heat transport, joules of heat, radiation impacts and thermal stratification are used. A Darcy-Forchheimer porous media is used to conduct fluid flow. Chemical reactions involving energies of activation and solutal stratum are additionally considered. The Keller-box technique is used to solve the resulting non-linear set of ordinary differential equations. The impacts of a number of variables are examined employing diagrams of quantity, velocity, and heat. Increased assessments of porousness, Darcy-Forchheimer, and Casson fluid characteristics result in a decrease in velocity trends. For improved measurements of Lewis number and solutal fractionated factors, the intensity pattern reduces. The skin friction factor increases with increasing Casson parameter estimate. In the instance of the porous and nonlinear stretching parameters, the Nusselt number rises. For increasing levels of the Lewis number and Brownian motion factors, the Sherwood number drops. Furthermore, Nusselt number ratios are estimated with Prandtl numbers with regard to current information available, which shows remarkable consistency. For varied incorporated parameters, streamlines, heatlines, and masslines additionally displayed.

The current study represents a sensitivity analysis of the flow of gold nanoparticles in blood over a rotating disk with the combined impacts of viscous dissipation, nonlinear thermal radiation, joule heating, and slippage using response surface methodology. We use response surface methodology to investigate the relationships between the model's parameters (the input parameters), and the response variables. Response Surface Methodology is a useful method for finding the best values for the input parameters that improve the output. It can also help researchers create a list of experiments to predict the output. We often use response surface methodology with sensitivity analysis to see how the output depends on the input parameters and to suggest the optimal values of them. After incorporating the effects of MHD, viscous dissipation, nonlinear thermal radiation, and joule heating, the boundary layer flow equations are solved using NDSolve command of Mathematica. The influences of dimensionless parameters on all flow profiles and physical quantities are presented and discussed. The arithmetic has been considered for a specific range of values for the apparent parameters in order to calculate and analyze the physical quantities of interest for various relevant parameters, for instance 2≤M≤5, 0≤β≤2, 0.6≤A≤1.5, 0.1≤Br≤0.65, 0.5≤δ≤2, 0≤φ≤0.15, 15≤Pr≤21, 0.1≤Rd≤1.5. For sensitivity analysis, we consider skin friction coefficient and local Nusselt number for three independent input parameter namely, the radial stretching rate, the magnetic field parameter, and the thermal slip parameter. After using the statistical measures such as residual quantile – quantile plots, hypothesis testing, and adjusted R2, we concluded that our models for the skin friction coefficient and local Nusselt number are best fitted.

Artificial neural networks (ANNs) have a wide range of applications in science and technology. Artificial neural networks (ANNs) widely utilized in image and speech recognition, neural language processing, drug discovery, genomics and bioinformatics, Robotics and control systems, material science and energy and power system. Due to the above applications, the main focus of this article is to scrutinize the impact of inclined magnetic field on a cross nanofluid flow with slip velocity and convective boundary conditions over a variable porosity. Gold (Au) nanoparticles are suspended in base liquid blood. Thermal stratification and heat generation with joule heating impact is taken in the energy equation in order to see the heat transfer. To transform the non-linear partial differential equations (PDE's) into non-linear ordinary differential equations (ODE's) utilized the von-Karman similarity transformation parameters. For the solutions of the non-linear ODE's, the 4th- order Runge-Kutta numerical method is employed. A dataset for the employed neural network back propagated Levenberg-Marquard scheme (NN-BLMS) is generated for various estimations of the embedded parameters like Weissenberg number, magnetic parameter, angle of inclination, porosity and permeability parameters, thermal stratification parameter by utilizing the 4th-order Runge-Kutta numerical scheme. The testing, validation and training methods of NN-BLMS are utilized to scrutinize the approximate solution of cross nanofluid with slip velocity and convective boundary conditions. The performance of the proposed NN-BLMS to successfully solved the cross nanofluid model is endorsed via mean squared error, error histogram and regression analysis. Streamlines and heatlines are plotted for different parameters including in velocity and temperature equations.

The power that comes from renewable sources is made back faster than it is used. Infinitely renewable examples include solar and wind energy. There are many sources of clean energy all around us. Motive behind current study: A framework has now been developed throughout this research to investigate the impact of the sun's rays on novel Xue tetra hybrid magnetized cross nano-liquid as it moves through an expanding sheet inside that PV sheet of a solar module installed on top of such an offshore solar oil field. A novel Xue tetra hybrid nanofluid model has been developed and utilized to explore the impact of tetrahybrid nanoparticles on liquid flowing in order to investigate heat transport analysis. By directing the liquid's motion through a magnetic field, we may examine its velocity impact. The concentration aspect of nanofluid has been examined by including homogeneous and heterogeneous chemical processes, and indeed, the temperature accessibility of cross-nanofluid is obtained by taking into consideration effects like thermal conductivity and thermal radiation. Technique: The PDEs derived from the working prototype are then subjected to the resemblance factors, yielding the ODEs. The bvp4c scheme is used to get numerical results. The procedure is an ODE solver that belongs to the Runge-Kutta family. In order to provide precise answers in the fourth and fifth orders, it performs six function evaluations. The discrepancy between them is therefore interpreted as the solution's (fourth-order) inaccuracy. Adaptive stepsize integration techniques greatly benefit from this error estimation. Fehlberg's (RKF) integration strategy is quite similar to Cash and Carp technique. Significant finding: From obtained results, it is detected that the addition of novel tetrahybrid nanoparticles in the conventional liquid (Xue tetrahybrid nanofluid) enhances heat transfer rate and temperature profile more quickly in contrast to conventional ternary hybrid nanofluid and dihybrid nanofluid available in the existing literature. The thing which makes the present work novel and one step ahead in contrast to existing available literature is the development and implementation of a tetrahybrid nanofluid model in contrast to conventional ternary hybrid and dihybrid nanofluid models. Tetra hybridity nanoliquid generates extra heat in distinction to already existing ternary hybridity and dihybrid nanofluid models and more heat is absorbed by PV sheets in the existence of tetrahybrid nanoparticles. Conclusions: When the nanomaterials are submerged inside this liquid, their temperature increases throughout both the shear thinning and shear thickening cases. This is because the homogeneous chemical reaction mimics the migration of nanoparticles within the liquid. The increased magnetic force, in addition to an enhancement of Lorentz's force, slows down the nanofluid motion. The increased volume percentage of tetrahybrid nanoparticles, thermal radiation, and thermal conductivity boost the heat that's captured by a PV sheet, and that heat is utilized for other functions, such as drilling or navigation, on that solar offshore rig. Cost analysis: Cost analysis has also been presented in terms of Pakistan offshore oil rigs in terms of solar panels and diesel generators and it is observed that 49% cost is reduced if we replaced offshore oil rigs with solar-powered energy.

In recent years, low power consumption and portable devices have been developed that will be connected and used everywhere. However, this explosion will bring critical challenges to electricity consumption. In this work, copper and zinc electrodes are embedded in prickly pear plant as an electricity generation has been analysed and evaluated. Many experimental setups have been performed to determine the optimum method to collect the maximum amount of energy from the living plant. They study the influence of distance between electrodes, influence of the electrode’s size, influence of the electrode’s depth, effect of the couple electrodes number, and effect of series and parallel connection to harvested energy. Therefore, a combination of series and parallel connection among the leaves can be installed to harvest higher voltage and current. The experimental results show that 58,8 mW electrical power can be harvested using 18 pairs of electrodes embedded in 6 leaves. The produced energy is used to power up low-power devices such as a calculator or a light emitting diode (LED) and can be stored in a capacitor or a battery.

Thermophysical properties such as latent heat, viscosity and melting temperature could be changed for different physical properties of dispersed nanoparticle such as size, shape, and concentration. In this study, Nanocomposites-Enhanced Phase Change Materials NePCM are formed by dispersing Aluminium (Al) and Copper (Cu) nanoparticles into paraffin wax in various mass fractions (0.1, 0.3, 0.6, 1, 2.5 and 5%). The impact on the thermophysical properties of paraffin wax by the nanoparticles is also investigated. Heat conduction and differential scanning calorimeter experiments are used to investigate the effects of different nanoparticle concentrations on the melting point, solidification point, and latent capacity of nanocomposites. Experimental results show that the dispersion of nanoparticles of Al and Cu can decrease the melting temperature and increase the solidification temperature of PCM. this dispersion could also be limited due to increase in dynamic viscosity of the NePCM. Furthermore, Al and Cu nanocomposites with mass fractions of 2% and 1%, respectively, show better enhancements in the thermal storage characteristics of the paraffin compared to the next higher mass fraction.

This work reported to investigate convective flow of non-Newtonian fluid effect on an exponentially stretchable surface. Effect of nanoparticle is considered in heat and mass equation. The transformation technique utilized on dimensionless equations is converted to non-dimensionless equations are solved thought numerical approach Bvp4c. Influence of approatiate analysis of velocities, heat and mass transport are scrutinized through figures. Furthermore, the comparative analysis of drag forces, Nusselt number and Sherwood number are evaluated over and done with tabulated values. It is give details that the temperature field strengthens with intensification in thermophoresis and random diffusions. Similarly, rises in thermophoresis effect parameter both temperature and concentration profile increasing.

To improve heat transfer, this work provides a unique theoretical mathematical model of ternary hybrid nanofluid. In this analysis, the tri-hybrid nanoparticles TiO2, Al2O3, and AA7072 are submerged in ethylene glycol (EG), resulting in the mixture TiO2+Al2O3+AA7072/EG. The tri hybridity nanofluid is considered 3-D flowing via a rotate permeable cone embedded in Darcy-Forchheimer porousness material in the existence of fluctuating temperature generating (sink) and current radiate fluxing. The Keller box scheme (KBS) is exploited to resolve the liquid flowing and temperature equations numerically after converting them to ordinary differential equations employing similarity transformations. The results are graphed, and it is shown that the tri-hybrid nanofluid (THNF) has superior thermal conductance to the hybrid nanofluid (HNF) and that the fluid's velocity and temperature develop as a consequence of enlargement in thermal radiative fluxing and variable thermal conductivity effects. Raising values of De and Fr decline drag friction but drag friction coefficient values are improved as a result of positive variation in M, Re, ς, and λ. It is apparent that the rate of heat transference amplifies owing to magnification in QT, QE and Rd but the heat transfer rate diminishes due to magnification in Re and Fr. Incremental change in volume fraction of nanoparticles φ=0.005 to 0.03 delivers more heat in the case of tri-HNFs TiO2+Al2O3+AA7072 in contrast to ethylene glycol based TiO2+Al2O3 fluid. The optimal percentage error diminishes for the drag friction phenomenon from 1.4% up to 1.1% by adopting De from 1 to 1.5 and λ=0.5. The percentage error in terms of heat transfer rate is getting smaller from 3.6% to 3.0% because of a positive change in QT by keeping Rd=1.5.

Due to its wide range of uses in numerous manufacturing, technological, and industrial processes, mineral oil (MO) is extremely significant. Mineral oil (MO) is used in the manufacture of PVC, polystyrene, as a lubricant and cutting fluid, thermoplastic rubber, glossing products, wood products, cleaning products, lamp oil, glues, toys, veterinary, cosmetic, food preparation, and other things. Due to the above applications, this article deals with the exact solution of unsteadiness naturally convective flowing of Maxwell nanofluid with radiation and uniform heat flux. Al2O3 nanoparticles are suspended in so-called mineral oil to make a homogeneous solution of nanofluid. The problem is demonstrated regarding coupled PDEs with initial and boundary conditions. Certain dimensionless factors are utilized to make the governing equation into a dimensionless structure. The solution for energy and momentum profiles is captured through the Laplace transform method. To predict heat transport and shear stress at the wall, the temperature and velocity gradient is also calculated. In the lack of the radiation factor, the relevant heat equation is simplified to the well-known solution in the literature. These solutions are greatly affected by the variety of different dimensionless variables like the thermal radiation parameter, volume fraction, and Grashof number. In a specific situation, the solutions relating to Newtonian fluids are retrieved, and a graphic juxtaposition of Newtonian and Maxwell fluids is displayed. Finally, the impact of pertinent parameters is shown by plotting graphs. The range of the pertinent parameters is 0.1≤λ≤0.4, Gr=5×K(K=1,2,3,4), 0.01≤χ≤0.04, Nr=5×K(K=1,2,3,4), t=1,3,5,7 while Pr=158 is fixed for mineral oil. The volume fraction declines the nanofluid's temperature while accelerating the velocity. The amplification in the Grashof number and radiation parameter improves the velocity. The increasing Maxwell fluid factor enhances the nanofluid's velocity. A decrease in the nanofluid's shear stress occurs, but after certain estimations of y, the nanofluid's shear stress goes up against the Maxwell fluid factor.

This study presents an experimental real case study on the performance optimization of a flat plate solar collector (FPSC) by integrating a layer of phase change material (PCM) and a heat sink. The system was tested under the semi-arid climatic conditions of Abha, Saudi Arabia. Based on preliminary experimental testing on conventional FPSCs, the novel composite structure of the PCM material was developed by mixing polyethylene glycol (PEG) and magnesium hydroxide (Mg (OH)2) in an absolute ethanol solution. The PEG/Mg (OH)2 PCM was installed beneath the pipe and had a lower supercooling value, a higher latent heat value, and thermal stable characteristic, thus increasing the thermal performance of the FPSC. The results showed that using a PCM ensured that the collector continued to deliver hot water for a longer period of time. Furthermore, a heat sink was attached to the PCM layer for proper temperature distribution. The results demonstrated that the FPSC equipped with a PCM and heat sink produced hot water for a longer period of time in the evening while having a lower output temperature in the morning. Also, the average daily FPSC thermal efficiency was enhanced by 6–8% by adding only PEG/Mg (OH)2 PCM as compared with conventional FPSCs and those with PCMs and heat sinks.

This study investigates the performance of a hybrid system that combined thermoelectric generators (TEG) with a solar flat plate collector system (SFPC) to turn more renewable energy into useable energy under normal operating and environmental conditions. A multi-month case study was first time conducted to explore the performance of SFPC with and without TEGs under the cold climatic conditions of Abha, Saudi Arabia. The result demonstrates that the heat losses from the rear surface of the SFPC's absorber plate were effectively utilized by TEGs, thereby decreasing overall heat losses and increasing the SFPC's overall thermal efficiency. Further, it was found that adding TEGs at the rear surface of SFPC's absorber plate improves thermal efficiency and exergy efficiency by 8.4% and 1.3%, respectively. The hybrid TEG-SPFC system can turn waste heat into useable electricity, with a peak power output of 2.2 W at midday. Maximum power was generated around midday, when the temperature differential between the upper and lower layers of TEGs was greatest. In addition, it was noticed that the thermal efficiency of the SFPC diminishes when the inlet water temperature rises. A hybrid TEG-SFPC system's exergy efficiency depends on ambient temperature variation and solar irradiance.

The magnetohydrodynamics boundary layer flow of a Casson fluid in rotating frame through porous medium caused by exponentially stretching surface is studied numerically in this piece of research. To investigate the transport properties of thermal and solutal energy, the phenomenon of relaxation time for thermal waves with chemical reaction effects is incorporated. Additionally, the bio-convection and process of stratification is also supposed in energy transport mechanism. The numerical outcomes of the problem presented graphically are obtained against the variation in physical constraints. The resistance to fluid motion improves as the Casson parameter is increased in its magnitude, therefore, the flow field is reduced. The higher values of thermal relaxation time slow down the heat waves propagation.

Abstract Manufacturing waste has been quickly increasing over time as a result of the fast-rising population as well as the consumption of foods that are thrown away dishonestly, resulting in environmental contamination. As a result, it has been suggested that industrial waste disposal may be considerably reduced if it could be integrated into cement concrete manufacturing. The aim of this study is to analyze the properties of concrete employing waste glass (WG) as a binding material in proportions of 5%, 10%, 15%, 20%, 25%, and 30% by weight of cement. The fresh property was assessed using a slump cone test, while mechanical performance was assessed using flexural, compressive, splitting tensile, and pull-out strength after 7, 28, and 56 days. Furthermore, microstructure analysis was studied by scan electronic microscopic (SEM), Fourier-transform infrared spectroscopy (FTIR) and thermo-gravimetric analysis (TGA) test. The results reveal that the addition of discarded glass reduces the workability of concrete. Furthermore, mechanical performance was increased up to a 20% substitution of waste glass and then gradually declined. Waste glass can be employed as a micro filler or pozzolanic material without affecting the mechanical performance of concrete, according to microstructure research.

To decrease indoor relative humidity and have relaxing environments, small dehumidifiers are widely used in tropical climatic. Due to the benefits of eco-friendly, small size and silence operation, the thermoelectric dehumidifier has gained interest but has limited practical application due to poor efficiency. Therefore, this study investigates the dehumidification characteristics of the thermoelectric module powered by a photovoltaic system for the production of fresh water under real climatic conditions. The performance of a novel prototype named as the Photo-Thermoelectric Dehumidifier (PVTE-D) was investigated both numerically and experimentally in different combinations of airflow rate and input power. The results obtained from the experiment suggested that the water condensate collection was increased by increasing the input power from a PV panel to the TE-D. In the month of May, the maximum water condensate collection of 1,852.3 mL/hr was attained at the input supply of 6 A and 5 V to the PVTE-D system. In the majority of cases, when the airflow rate is below 0.013 kg/s, maximum collections of water condensate have been achieved. This study provides a detailed understanding of the optimally suitable structural parameters of the PVTE-D under different operating conditions and reveals a novel configuration for higher water condensation capacity. HIGHLIGHTS Photovoltaic powered thermoelectric dehumidification system.; Simulation and experimental study of PVTED system.; Optimum performance parameter evaluation by regulating input power and air flow rate.;

This study investigates the parametric electrical and thermal performance of a novel photovoltaic trombe wall with a venetian blind system (PVTW-VB) in a semi-arid climatic conditions. A three-dimensional computational fluid dynamics (CFD) model is developed to determine the optimal parametric configuration for the PVTW-VB and is validated using experimental data. The experimental results indicated that the CFD model could accurately predict the operational performance of the PVTW-VB system. According to the findings, the VB spacing within the air gap, the VB angle, and the PVTW air flow rate should be 0.09 m, 60°, and 0.2 m/s, respectively. Additionally, PVTW-VB is compared with PVTW without VB. The average electrical power generation and PV panel surface temperature are found to be 8.6% higher and 3.2 °C lower in case of PVTW-VB configuration, respectively. Thermal regulation studies are conducted for three different test room configurations (i.e., a normal test room, test room with PVTW and test room with PVTW-VB). The study found that PVTW-VB system reduces the thermal load of the test room.

In this research, the impacts of utilizing nano-embedded absorber coating in an auxiliary heater of a greenhouse drying system on the thermal and drying performances have been surveyed empirically. In this context, triple-flow solar air collectors with and without CuO nano-enhanced absorber coating have been designed and manufactured. Designed collectors then integrated to even-span greenhouse dryers to be used as an auxiliary heating device. In the experiments, greenhouse dryers have been tested with and without auxiliary heaters at constant flow rate which is 0.014 kg s−1. According to the experimental findings, utilizing triple-flow solar air heating device with and without nano-embedded paint decreased the drying time as 35.71% and 26.66%, respectively. Thermal and exergetic efficiencies for newly developed collectors were found between the range of 70.39–75.11% and 9.05–10.18%, respectively. In addition, specific energy consumption values were decreased by using collectors with and without nano-enhanced modification from 2.51 to 2.11 and from 2.61 to 2.18 kWh/kg, respectively. Attained outcomes of this study showed the successful utilization of nano-enhanced absorber coating in the auxiliary heating system of the greenhouse dryer.

The increasing use of renewable energy sources during the last two decades has increased the importance of research and development of energy storage systems. In this study, a new design of a thermal energy battery (TEB) was fabricated and experimentally investigated. This battery is composed of an aluminum finned tube heat exchanger inserted within a tank in plexiglass filled with 2.5 kg of nano-enhanced paraffin. Water was used as heat transfer fluid (HTF). To evaluate the influence of aluminum nanoparticles on the thermal behaviour of the TEB, the melting process of PCM was monitored using thermocouples. A series of experimental measurements were conducted and analysed. It was shown that the TEB's charging time is enhanced with increasing flow rate and temperature of HTF. The charging process of the TEB was found to be expedited by up to 30% using 1.0 wt% nanoparticles of aluminum with the paraffin Wax.

Metal hydride (MH) hydrogen storage needs an external heat source to release the stored hydrogen. To enhance the thermal performance of MHs, the incorporation of phase change materials (PCM) is a way to preserve reaction heat. This work proposes a new MH-PCM compact disk configuration (i.e., a truncated conical MH bed surrounded by a PCM ring). An optimization method is developed to find the optimal geometrical parameters of the MH truncated cone, which is then compared to a basic configuration (i.e., a cylindrical MH surrounded by a PCM ring). Moreover, a mathematical model is developed and used to optimize the heat transfer in a stack of MH-PCM disks. The optimum geometric parameters found (bottom radius of 0.2, top radius of 0.75 and tilt angle of 58.24) allow the truncated conical MH bed to reach a faster heat transfer rate and a large surface area of higher heat exchange. Compared to a cylindrical configuration, the optimized truncated cone shape enhances the heat transfer rate and the reaction rate in the MH bed by 37.68%.

A significant growth in solar photovoltaic (PV) installation has observed during the last decade in standalone and grid-connected power generation systems. The solar PV system has a non-linear output characteristic because of weather intermittency, which tends to have a substantial effect on overall PV system output. Hence, to optimize the output of a PV system, different maximum power point tracking (MPPT) techniques have been used. But, the confusion lies while selecting an appropriate MPPT, as every method has its own merits and demerits. Therefore, a proper review of these techniques is essential. A “Google Scholar” survey of the last five years (2015-2020) was conducted. It has found that overall seventy-one review articles are published on different MPPT techniques; out of those seventy-one, only four are on uniform solar irradiance, seven on non-uniform and none on hybrid optimization MPPT techniques. Most of them have discussed the limited number of MPPT techniques, and none of them has discussed the online and offline under uniform and hybrid MPPT techniques under non-uniform solar irradiance conditions all together in one. Unfortunately, very few attempts have made in this regard. Therefore, a comprehensive review paper on this topic is need of time, in which almost all the well-known MPPT techniques should be encapsulated in one paper. This article focuses on classifications of online, offline, and hybrid optimization MPPT algorithms, under the uniform and non-uniform irradiance conditions. It summarizes various MPPT methods along with their mathematical expression, operating principle, and block diagram/flow charts. This research will provide a valuable pathway to researchers, energy engineers, and strategists for future research and implementation in the field of maximum power point tracking optimization.

In blood flow and fluid mechanics, Jeffrey fluid has a vital role because of its viscoelastic characteristics. The application of Caputo–Fabrizio time-fractional derivatives for dusty-type Jeffrey fluid is discussed in this article. The concept of free convection flow of dusty Jeffrey fluid between infinite vertical parallel static plates is generalized. Free convection and buoyant force produce the flow. Furthermore, the fluid contains homogeneous dispersion of all spherical dust particles. Heat transmission is therefore taken into account for free convection. Nondimensional variables are used to write the dusty Jeffrey fluid classical model in dimensionless form. Also, the dimensionless model is transformed into a generalized dusty Jeffrey fluid model via a fractional derivative. Using the finite sine and Laplace method, the governing equations of the generalized dusty Jeffrey fluid model have been solved exactly. Numerical computation is used to study the physics of velocity and temperature profiles for a variety of embedded parameters. The collected results are discussed in detail and are shown graphically in this report. Mathcad-15 is used to plot the graphical outcomes for Jeffrey fluid, dust particle, and temperature profiles. Furthermore, skin friction and the Nusselt number are calculated. Table demonstrates how the rate of heat transmission reduces as the Peclet number’s value rises. Similarly, Table demonstrates that skin friction increases as the fractional parameter rises. By increasing the dusty Jeffrey fluid parameter λ, both velocity profiles are retarded.

Integrating a solar water heater (SWH) with a phase change material (PCM)-based latent heat storage is an attractive method for transferring load from peak to off-peak hours. This transferring load varies as the physical parameters of the PCM change. Thus, the aim of this study is to perform a parametric analysis of the SWH on the basis of the PCM’s thermophysical properties. A mathematical model was established, and a computation code was developed to describe the physical phenomenon of heat storage/release in/from the SWH system. The thermal energy stored and the energy efficiency are used as key performance indicators of the new SWH–PCM system. The obtained numerical results demonstrate that the used key performance indicators were significantly impacted by the PCM thermo-physical properties (melting temperature, density, and latent heat). Using this model, various numerical simulations are performed, and the results indicate that, SWH with PCM, 20.2% of thermal energy on-peak periods load is shifted to the off-peak period. In addition, by increasing the PCM’s density and enthalpy, higher load shifting is observed. In addition, the PCM, which has a lower melting point, can help the SWH retain water temperature for a longer period of time. There are optimal PCM thermo-physical properties that give the best specific energy recovery and thermal efficiency of the SWH–PCM system. For the proposed SWH–PCM system, the optimal PCM thermo-physical properties, i.e., the melting temperature is 313 K, the density is 3200 kg/m3, and the latent heat is 520 kg/kg.

Thermal performance and phase-change dynamics in a channel having a cavity equipped with a heater and phase-change material (PCM)-packed bed (PB) region are analyzed during nanoliquid convection under an inclined magnetic field. Curvature of the upper wall above the PCM zone is also considered by using the finite element method. Impacts of curvature of the upper wall (between 0.01H and 0.6H, H-channel height), strength of magnetic field (MGF) (Hartmann number between 0 and 40), height (between 0.1H and 0.4H) and number (between 5 and 17) of heaters on the thermal performance and phase-change dynamics are studied. In the interior and wall near regions of the PCM-PB, the curvature effects become opposite, while phase completion time (tF) rises by about 42% at the highest radius of the curvature. Imposing MGF and increasing its strength has positive impacts on the phase change and thermal performance. There is a reduction in tF by about 45.2% and 41.8% when MGF is imposed at Ha = 40 for pure fluids and nanofluids. When thermal performance for all different cases is compared, using MGF+nanofluid+PCM provides the most favorable case. When the reference case (only pure fluid without MGF and PCM) is used, including nanoparticles results in an improvement of 33.7%m while it is further increased to 71.1% when PCM-PB is also installed. The most favorable case by using MGF, nanofluid and PCM-PB results in thermal performance improvement of about 373.9% as compared to the reference configuration.

The current research focuses on formulating a new class of Therminol55-based nanofluids that incorporates an MXene/Al2O3 nanocomposite as the new class of dispersant at three different concentrations of 0.05, 0.10, and 0.20 wt%. The optical and thermophysical properties of the formulated nanofluid are assessed experimentally. Zeta potential and FTIR analyses are employed to evaluate the composite particles' surface charge and chemical stability, respectively. Thermal conductivity is observed to increase with nanoparticle loading and maximally augmented by 61.8% for 0.20 wt%, whereas dynamic viscosity increased with adding nanoparticles but remarkably dropped with increasing temperature. In addition, the prepared TH55/MXene + Al2O3 samples are thermally stable up to 200 °C according to TGA analyses. Moreover, the proposed correlations for the thermal conductivity and viscosity showed good agreement with the experimental data. The study’s findings suggest that the formulated nanofluid could be a viable contender to be used as a heat transfer fluid in the thermal sector.

Coupled effects of double porous fins and inhomogeneous magnetic field on the cooling performance of multiple nanojet impingement for a corrugated surface were numerically analyzed. Different values of magnetic field parameters (strength, inclination, and amplitude of spatially varying part) and double porous fin parameters (inclination and permeability) were used, while finite element method is used as the solution method. When parametric computational fluid dynamics (CFD) simulations were performed, there were 162.5% and 34% Nusselt number (Nu) enhancement with magnetic field for flat and wavy surfaces, respectively. The variations of average Nu became 36% and 24% when varying the inclination and amplitude of inhomogeneous magnetic for a flat surface, while the amounts were 43.7% and 32% for a corrugated one. The vortex distribution in between the jets and cooling performance was affected by the variation of double porous fin permeability and inclination. An optimization method was used for the highest cooling performance, while the optimum set of parameters was obtained at (Ha, Amp, Da, Ω) = (0.224, 0.5835, 7.59×10−4, 0.1617). By using the double porous fins and inhomogeneous magnetic field, excellent control of the cooling performance of multiple impinging jet was obtained.

Recent developments in the controlled-release fertilizer (CRF) have led to the new modern agriculture industry, also known as precision farming. Biopolymers as encapsulating agents for the production of controlled-release fertilizers have helped to overcome many challenging problems such as nutrients’ leaching, soil degradation, soil debris, and hefty production cost. Mechanistic modeling of biopolymers coated CRF makes it challenging due to the complicated phenomenon of biodegradation. In this study, a machine learning model is developed utilizing Gaussian process regression to predict the nutrient release time from biopolymer coated CRF with the input parameters consisting of diffusion coefficient, coefficient of-variance of coating thickness, coating mass thickness, coefficient of variance of size distribution and surface hardness from biopolymer coated controlled-release fertilizer. The developed model has shown greater prediction capabilities measured with R2 equalling 1 and a Root Mean Square Error (RMSE) equalling 0.003. The developed model can be utilized to study the nutrient release profile of different biopolymers’-coated controlled-release fertilizers.

Significant growth in solar photovoltaic (PV) installation has been observed during the last decade in standalone and grid-connected power generation systems. However, the PV system has a non-linear output characteristic because of weather intermittency, which tends to a substantial loss in overall system output. Thus, to optimize the output of the PV system, maximum power point tracking (MPPT) techniques are used to track the global maximum power point (GMPP) and extract the maximum power from the PV system under different weather conditions with better precision. Since MPPT is an essential part of the PV system, to date, many MPPT methods have been developed by various researchers, each with unique features. A Google Scholar survey of the last five years (2015–2020) was performed to investigate the number of review articles published. It was found that overall, seventy-one review articles were published on different MPPT techniques; out of those, only four were on non-uniform solar irradiance, and seven review articles included shading conditions. Unfortunately, very few attempts were made in this regard. Therefore, a comprehensive review paper on this topic is needed, in which almost all the well-known MPPT techniques should be encapsulated in one document. This article focuses on online and soft-computing MPPT algorithm classifications under non-uniform irradiance conditions along with their mathematical expression, operating principles, and block diagram/flow charts. It will provide a direction for future research and development in the field of maximum power point tracking optimization.

In this study, the microclimate of the test room was regulated using thermoelectric air duct cooling system (TE-AD) operated at input powers-240 W, 360 W, 480 W, 600 W, 720 W, and 840 W, on subsequent nights. Fifteen (15) healthy male volunteers were recruited to sleep under these test conditions and their sleep quality was assessed by studying objective measures such as sleep onset latency (SOL), mean skin temperature and heart rate as well as subjective parameters like predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD). There was a consistent improvement on all studied parameters when the power of the system was increased from 240 W to 720 W. The mean sleep onset latency time was reduced from (M = 40.7 +/− 0.98 min) to (M = 18.33 +/− 1.18 min) when the operating power was increased from 240 W to 720 W, denoting an improvement in sleep quality. However, increasing the power further to 840 W resulted in deteriorating cooling performance of the TE-AD system leading to an increase in temperature of the test room and reduction in sleep comfort. Analysis of subjective indices of thermal comfort viz. PMV and PPD revealed that subjects are highly sensitive towards variations in microclimate achieved by changing the operating power of the TE-AD. This device was also found to be environmentally sustainable, with estimated reduction in CO2 emission calculated to be around 38% as compared to the conventional air-conditioning.

The present research work analyzed the effect of design modification with radial grooves on disc brake performance and its thermal behavior by using additive manufacturing based 3D printed material maraging steel. Temperature distribution across the disc surface was estimated with different boundary conditions such as rotor speed, braking pressure, and braking time. Design modification and number of radial grooves were decided based on existing dimensions. Radial grooves were incorporated on disc surface through Direct Metal Laser Sintering (DMLS) process to increase surface area for maximum heat dissipation and reduce the stresses induced during braking process. The radial grooves act as a cooling channels which provides an effective means of cooling the disc surface which is under severe condition of sudden fall and rise of temperatures during running conditions. ANSYS software is used for transient structural and thermal analysis to investigate the variations in temperatures profile across the disc with induced heat flux. FE based thermo-structural analysis was done to determine thermal strains induced in disc due to sudden temperature fluctuations. The maximum temperature and Von Mises stress in disc brake without grooves on disc surface were observed which can severely affect thermal fatigue and rupture brake disc surface. It was been observed by incorporating the radial grooves that the disc brake surface is thermally stable. Experimental results are in good agreement with FE thermal analysis. DMLS provides easy fabrication of disc brake with radial grooves and enhancement of disc brake performance at higher speeds and temperatures. Therefore, DMLS provides an effective means of implementing product development technology.