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Electronic components cooling (ECC) for manufacturing and technological uses has become one of the most interesting topics that researchers have focused in the modern era. Because of the continuous minimization in the electronic components size and substantial quantity of heat generation; the traditional cooling methods cannot be able to follow rapidly reduction in such high amount of heat flux. The use of nanofluid is an intriguing possibility for ECC. Such advancements may result in advancements in the field of electronic equipment in addition to improved efficiency of energy. The present article proposes is to study the use of various types of nanofluids over different shapes for preventing redundant heat, to effectively control the thermal stress as well as to maintain the electronic components temperature. Some fascinating features related to utilizing nanofluids to ECC are also addressed. In addition, further study prospects and directions in this area are put forward. It can be noticed that the addition of γ-Al2O3 NPs in water increases the heat transmission efficiency by 37% and 28%, while keeping Reynolds numbers (Re = 601.3 and 210) respectively. The cooling ability of the automobile radiator upsurges up to 17.46% with the addition of Al2O3-NPs. [ABSTRACT FROM AUTHOR]

In this analysis, a bidirectional stretched sheet is used to produce a 3 D flow of Prandtl liquid with improve mass diffusion and heat conduction models. This study advances knowledge of magnetohydrodynamics, radiation impacts, and heat production in fluid dynamics and transport processes. The Prandtl fluid model is critical for modeling non-Newtonian fluids, capturing its viscoelastic features, and allowing for precise simulation in industrial applications. It gives a mathematical foundation for analyzing complex fluid behaviors, which is necessary for optimizing operations utilizing such fluids. It uses the boundary layer method to simplify the fundamental equations and Cattaneo–Christov double diffusion models. The optimal homotopy analysis method is used to solve nonlinear ODEs caused by non-dimensional similarity variables. This investigation undertakes the calculation of drag coefficient for surfaces mass transfer rates and heat transfer rates proximate to the solid boundary. Furthermore, it conducts a comprehensive analysis of the influences exerted by various parameters on concentration and temperature profiles employing graphical representations for a rigorous examination. The Prandtl fluid model describes the viscoelastic characteristics of non-Newtonian fluids through constitutive equations, dimensional evaluation, and numerical simulations, which are frequently validated by experiments. The results show that changes in thermal and concentration relaxation parameters are accompanied by a decline in temperature. Temperature field rises as the thermal radiation parameter and heat generation increases. The work's novelty consists in its advanced modeling of Prandtl non-Newtonian fluids via Cattaneo–Christov double diffusion models, which incorporate magnetohydrodynamics and radiation effects and use optimal homotopy analysis for accurate parametric analyses of heat and mass transfer. [ABSTRACT FROM AUTHOR]

This study investigated self-heating and off-gassing of Scots pine (Pinus sylvestris) wood pellets made from sawdust generated from separated mature and juvenile wood. The pellets were produced at an industrial scale and stored in large piles of about 7.2 tonnes. The production process involved drying the sawdust using three different methods and to varying moisture contents. The results indicated significant influences of both raw material type (F(6) = 61.97, p < 0.05) and drying method (F(2) = 65.38, p < 0.05) on the self-heating of the pellets. The results from the multiple regression analysis further showed that both the raw material type and pellet moisture content significantly influenced the temperature increase, with strong correlations observed for pellets produced using low-temperature drying (F(3, 14) = 83.52, multiple R2 = 0.95, p < 0.05), and medium temperature drying (F(3, 13) = 62.05, multiple R2 = 0.93, p < 0.05). The pellets produced from fresh mature wood sawdust were found to be more prone to self-heating and off-gassing while steam drying the sawdust at high temperature and pressure led to a significant reduction in heat and gas generation across all materials. The heightened self-heating and off-gassing in mature wood pellet can be attributed to a higher proportion of sapwood in the raw material. The probable explanations to the observed differences are in line with biological mechanisms for self-heating and off-gassing, as well as the chemical oxidation of fatty and resin acids. [ABSTRACT FROM AUTHOR]

Effective operation strategies in the solid oxide fuel cell (SOFC) can adjust the spatial distribution of temperature gradient favoring the long-term stability. To investigate the effects of different operating conditions on the thermal behavior inside SOFC, a three-dimensional model is developed in this study. The model is verified by comparing it with the experimental data. The heat generation rate and its variation under different operating conditions are analyzed. The combined effects of operating voltage and gas temperature are considered to be the key factor influencing the temperature gradient. Compared to the original case, the temperature of SOFC decreases by 21.4 K when the fuel velocity reaches 5 m/s. But the maximum temperature gradient increases by 21.2%. Meanwhile, higher fuel velocities can eliminate about 32% of the area with higher temperature gradient. And when the oxidant velocity reaches 7.5 m/s, the peak temperature gradient effectively decreases by 16.59%. Simultaneous adjustment of the oxidant and fuel velocities can effectively reduce the peak temperature gradient and increase the safety zone. The effects of operation conditions on the temperature gradient of the cell are clarified in this study, which can be a reference for further research on the reliability of SOFCs. [ABSTRACT FROM AUTHOR]

This study examines the effects of Newtonian heating along with heat generation, and thermal radiation on magnetohydrodynamic Casson fluid over a vertical plate. At the boundary, the Newtonian heating phenomena has been employed. The problem is split into two sections for this reason: momentum equation and energy equations. To transform the equations of the given model into dimensionless equations, some particular dimensionless parameters are defined. In this article, generalized Fourier’s law and the recently proposed Caputo Fabrizio fractional operator are applied. The corresponding results of non-dimensional velocity and heat equations can be identified through the application of Laplace transform. Moreover, Tzou’s algorithm as well as Stehfest’s algorithm is implemented to recognize the inverted Laplace transform of heat and momentum equations. Finally, a graphical sketch is created using Mathcad 15 software to demonstrate the results of numerous physical characteristics. It has been reported that the heat and velocity drop with rising Prandtl number values, whereas the fluid’s velocity has been seen to rise with increasing Grashof number values. Additionally, current research has shown that flow velocity and temperature increase with rising values of a fractional parameter. [ABSTRACT FROM AUTHOR]

Heat transport analysis corresponded to converging/diverging consideration has attained the attensions because of engineering and industrial utilization. Typical examples encompass cold drawing operation in polymer industry, enhancement of rate of heat transport during process of heat exchangers for milk flowing, molten polymers extrusion via converging dies, processing plants, power stations, and numerous others. Due to this fact, the present analysis has been established. The current research describes the hybrid nanofluid flow through convergent/divergent channel in the regime of hydromagnetic phenomenon. Here, water based nanoparticles i.e., graphene oxide and polystyrene are considered. Heat transport under the viscous dissipation and heat generation/ absorption is evaluated. Velocity slip condition is also imposed on channel wall. Suitable variables are employed to get strong form of non-dimensional coupled equations which are solved by using homotopic analytical technique. The results for velocity and temperature against pertinent parameters are analyzed through graphs. Effects of skin friction and Nusselt numbers are presented through graphs. The current investigation tells us that surface drag has diminished for Reynolds and Hartmann number. Furthermore, dissipative factor intensifies the heat transport rate. Owing by such applications, the present examination has been established. [ABSTRACT FROM AUTHOR]

The study aims to investigate the performance of a thermal management system for lithium-ion batteries in electric vehicles (EVs) by utilizing a helical coiled pulsating heat pipe (HC-PHP) combined with a hybrid nanofluid consisting of Al2O3–MWCNT–ethylene glycol. The experimental investigation focuses on evaluating the effectiveness of this system under various operating conditions. The outcomes of this study will provide valuable insights into the influence of thermal management on power output, driving range, and safety of EVs. During a continuous discharge process at room temperature of 25 °C and discharge rates of 1C, 2C, and 3C, the lithium-ion battery's temperature remains below 42 °C, ensuring that it does not exceed the specified safety limit. Additionally, the maximum temperature gradient across the battery, which indicates temperature variation within the battery, remains below 2 °C. These findings demonstrate the effectiveness of the thermal management system in maintaining safe and uniform temperature distribution during high-discharge operations. The observed results provide strong evidence for the exceptional heat dissipation capabilities of the thermal management system utilizing HC-PHP and an Al2O3–MWCNT–ethylene glycol-based nanofluid. The system effectively minimizes temperature gradient and enhances thermal uniformity across the battery surface. As a result, the HC-PHP ensures optimal performance of the lithium-ion battery by maintaining temperatures within the desired range of 20–50 °C, which is crucial for its reliable operation. [ABSTRACT FROM AUTHOR]

This article studies the impact of multi-nanoparticles on the entropy generation where heat transfer in Oldroyd-B fluid is subjected to Joule heating and heat generation. C 2 H 6 O 2 is assumed to obey the constitutive behavior in the context of the Oldroyd-B model. Three types of nanoparticles ( Al 2 O 3 , TiO 2 and SiO 2 ) are assumed to be dispersed simultaneously in C 2 H 6 O 2 . The numerical scheme is used for the numerical simulations and simulations are observed and various predictions are made. The dynamics of entropy generation versus relaxation and retardation times. Momentum relaxation time is helpful in controlling entropy generation. It is also observed that C 2 H 6 O 2 with Al 2 O 3 has minimum entropy generation relative to C 2 H 6 O 2 with Al 2 O 3 and TiO 2 and C 2 H 6 O 2 with Al 2 O 3 , TiO 2 and SiO 2 . Relative to hybrid and mono-nanoparticles, the highest wall shear stresses are noticed in C 2 H 6 O 2 with tri-nanoparticles is observed. Momentum retardation time enhances entropy generation. Therefore, it is recommended not to use fluid with Oldroyd-B behavior in mechanisms where entropy generation is not required. In mechanisms where entropy generation is not required, the base fluid or nanofluid should not be heat-generating because heat generation helps in enhancing the generation of entropy. However, heat-absorbing fluid would be favorable for the minimization of entropy. [ABSTRACT FROM AUTHOR]

In this research, we examine four models—a rotating cone with a stationary disc, a stationary cone with a revolving disc, a co-rotating cone-disc, and a counter-rotating cone-disc—to determine the role of magnetohydrodynamic (MHD) natural convective flow of hybrid nanofluid and heat transfer in a small gap between cone and disc. An amalgamation of two nanoparticles magnesium oxide M g O and copper oxide C u O is used in water H 2 O . The computations of the proposed model were limited to Reynolds number 12 with a corresponding conical angle at α = 4 ∘ . The temperature of a disc surface varies radially. An innovative aspect of the proposed framework is the convective flow of radiative hybrid nanofluid in the presence of buoyancy force and magnetic field. The governing three-dimensional momentum and energy equations are solved for velocity and temperature fields using befitting similarity transformations. The bvp4c technique has been applied. Graphs demonstrate the effect of dimensionless parameters on flow characteristics. Heat transfer rates are calculated at both the cone and disc surfaces for all four models and found that the co-rotation model produces a higher heat transfer rate at the cone surface. The proposed model has characteristics in solar thermal systems, electronics cooling, energy storage, biomedical, and waste heat recovery. This study has been validated with prior research. [ABSTRACT FROM AUTHOR]

The investigation focused on a Maxwell fluid's convective double diffusive flow, considering the influences of chemical reaction radiation on a permeable moving horizontal plate. Factors like heat generation, Newtonian heating conditions, and the effect of MHD were also included in this study. The governing equations, presented as partial differential equations, are then transformed into ordinary differential equations (ODEs) via similarity transformation approach. MATLAB's built-in software, BVP4C, was considered to solve the resulting system of ODEs. The obtained solutions were presented as graphical representations illustrating the flow field, energy conservation, and concentration behaviours for different parameter combinations. The targeted parameter here is to be taken as a Newtonian heating condition on the boundary, so the critical discovery from this study is the increase in nondimensional temperature contour and Nusselt number profile as the Newtonian heating effect value increased. The Sherwood number profile rose as the chemical reaction effect value increased. We have rigorously validated our work by comparing it to existing research, and the results have demonstrated a remarkably high degree of alignment. Consequently, we can confidently assert that our code is accurate and effectively aligned with this field's existing body of knowledge. This validation process reinforces the reliability and validity of our work, underlining its robustness and correctness. [ABSTRACT FROM AUTHOR]

The investigation endorsed the convective flow of Carreau nanofluid over a stretched surface in presence of entropy generation optimization. The novel dynamic of viscous dissipation is utilized to analyze the thermal mechanism of magnetized flow. The convective boundary assumptions are directed in order to examine the heat and mass transportation of nanofluid. The thermal concept of thermophoresis and Brownian movements has been re-called with the help of Buongiorno model. The problem formulated in dimensionless form is solved by NDSolve MATHEMATICA. The graphical analysis for parameters governed by the problem is performed with physical applications. The affiliation of entropy generation and Bejan number for different parameters is inspected in detail. The numerical data for illustrating skin friction, heat and mass transfer rate is also reported. The motion of the fluid is highest for the viscosity ratio parameter. The temperature of the fluid rises via thermal Biot number. Entropy generation rises for greater Brinkman number and diffusion parameter. [ABSTRACT FROM AUTHOR]

The thermal behavior of flooded lead–acid batteries with different distances between their electrodes, in which there takes place a temperature rise, was investigated at different rates of charging and discharging of these batteries with the use of the PIV method. It was established that, in the case of small rates of charging and discharging of such a battery, a decrease in the distance between its electrodes leads to a decrease in the temperature rise and in the heat generation in it, while, in the case where these rates are large, the opposite effects take place. [ABSTRACT FROM AUTHOR]

The nanofluids extensively contribute to cope the new heat transport challenges facing by the engineering systems and industries including paint, ceramics, chemical, aerodynamics, electronics, and medical sciences, etc. Thus, the innovations in new nanoliquid models can be disregarded in light of broad applications spectrum. Therefore, the current work concerns with the thermal process of hybrid nanoliquid by adding the important physical phenomenon. The flow of bionanofluid is taken inside a uniform expanding/contracting channel. To increase the model novelty, the significant influence of Lorentz forces, porous media, and heating source is added in the problem formulation. The resultant bionanofluid model is then analyzed via VIM (variational iteration method) and provided a deep discussion. It is inspected that unvarying expansion/contraction in the range of α = 1.0 , 2.0 , 3.0 , 4.0 and α = - 1.0 , - 2.0 , - 3.0 , - 4.0 , the bionanofluid attained maximum velocity about the central portion and in rest of the part it declines. However, due to increased viscosity of hybrid nanofluid, it reduced rapidly than conventional nanofluid. By increasing the permeability from 0.1 to 0.4, a rapid decrease in the fluid movement is observed. Further, the heat transmission progress reduced against the porous medium and Lorentz forces. The heat generation effects boosted the heating performance of the hybrid nanofluid. Moreover, the skin friction and heat transport rate are also discussed. [ABSTRACT FROM AUTHOR]

The main theme of this research is to deliberate the irreversibility aspects of spinning nanofluid (PEG-H2O / ZrO2) and hybrid (PEG-H2O / ZrO2–MgO) nanofluid towards a movable sheet. Here a mixture of polyethylene glycol and water is utilised as a continuous phase fluid. Two different nanoparticles are considered, i.e., zirconium dioxide (ZrO2) and magnesium oxide (MgO). The heat transfer behaviour is examined and modelled subject to viscous dissipation, heat source and heat flux. Furthermore, the entropy generation problem is addressed by the second law of thermodynamics. Nonlinear dimensionless differential systems are developed by suitable variables. The given dimensionless systems are solved using numerical techniques (ND-solve method). Effects of influential variables on fluid flow, temperature, Bejan number and entropy rate for both PEG-H2O / ZrO2 and PEG-H2O / ZrO2–MgO fluids are graphically examined. A higher approximation of volume fractions rises the velocity profile, while reverse impact is seen for the Bejan number. An increment in rotation variable corresponds to increased velocity. A similar scenario is seen for the thermal field and entropy rate through the radiation effect. An opposite impact is seen for the Bejan number and entropy rate through the Brinkman number. An augmentation in temperature is seen for the Eckert number. Furthermore, we noticed that heat transport in a hybrid nanofluid (PEG-H2O / ZrO2–MgO) is higher than that for the nanofluid (PEG-H2O / ZrO2). [ABSTRACT FROM AUTHOR]

This present study involves examining the nature of 3D rotational MHD nanofluid flow through a stretching sheet. Alumina Al 2 O 3 –ethylene glycol C 2 H 6 O 2 -based nanofluid is considered in this investigation. A normal magnetic field acts on the sheet. Radiative thermal boundary condition with slip velocity has been considered. Suitable similarity transformation is used to derive a system of ordinary differential equations. The spectral quasilinearisation method (SQLM) is applied to solve this system. For curiosity, the skin friction coefficient and Nusselt number have been calculated. Due to effective heat generation and heat radiation, a significant temperature difference is produced. Besides, the impact of the variation in the volume fraction of nanoparticles is remarkable. The influence of key parameters has also been shown graphically. The graphical representation shows that the magnetic parameter declines in the radial velocity component, while the layout of the tangential component of velocity enhances in the form of a parabola with an enhancement of the magnetic parameter. Temperature layout is enhanced with the increasing values of the magnetic parameter, nanoparticle volume fraction, temperature ratio parameter, radiation parameter and Biot number. The generation of entropy enhances with the increase in the magnetic parameter, Brinkman number and Reynolds number, while nanoparticle volume fraction and temperature difference parameters decrease the entropy generation. For the engineering interest, the skin friction coefficient along the x-axis, y-axis and the local Nusselt number have also been calculated. The impacts of pertinent parameters on the skin friction coefficient along the x-axis, y-axis and the local Nusselt number are scrutinised numerically. We have compared our current result with the available studies for special cases ϕ = 0 , M = 0 and found that the results are in good agreement. [ABSTRACT FROM AUTHOR]

The objective of the current article is to probe entropy generation in EMHD thermal transports of hybrid nanofluid which has indeed been enhanced by better thermal transfer to handle growing heat density of tiny and other technological operations. Non-Newtonian fluids like Casson and Williamson are encrypted for this present physical model and also in the blood, gold (Au) and silver (Ag) are hybridized to form an extremely diluted, homogeneous combination. The non-linear PDE system of equations are synthesized into an ordinary differential system via appropriate self-similarity variables, which are then computed by utilizing the homotopy perturbation technique. Visual representations are used to demonstrate the effects of various factors. With a few exceptions, the model's study results are pretty close to those found in the literature. For various profiles, with the influence of active parameters, the results are displayed graphically. This shows that when the parameters of magnetic, Casson and Williamson fluids are inclined, the radial and azimuthal velocity profiles decrease, sharply it attains contradiction phenomena to the increasing electric field inputs. Entropy production increases for magnetic fields and the Bejan number exhibits declination. The predictions are pertinent to the delivery of targeted nanoparticle drugs in hematology. [ABSTRACT FROM AUTHOR]

Data on the geothermal resource base of Iceland are presented: 25 high-temperature (temperature over 200°C at the bottom) and 250 low-temperature (150°C) deposits. The similarity of the geological conditions and the main characteristics of thermal water intakes in Iceland and Kamchatka krai of Russia is noted. The analysis of the legal support of geothermal energy in Iceland, as well as the activities of the state institution Orkustofnun for licensing, research of geothermal deposits, and the creation of the world's largest library of geothermal literature, was carried out. The process of implementation of the IDDP state program for drilling and testing wells at the foot of the Krafla volcano at supercritical parameters (SCP) of fluids is described. The main characteristics of eight geothermal power plants (GeoPP) with a total capacity of 753 MW with electricity generation in 2021 of 6208 GW h are given and thermal schemes and cycles are described. It is indicated that the most powerful GeoPP in Iceland is Hellisheiði (303 МW), the geothermal coolant of which is supplied to Reykjavik, located at a distance of 19.5 km from it. This station is equipped with an installed system for the utilization of carbon dioxide into carbonate underground rocks. Power units with binary cycles were built at two GeoPPs: Husavik (2 MW) in the Kalina cycle and Svartsergi (7 × 1.2 MW) with organic coolant. It is noted that Iceland has the world's largest geothermal heat generation (2373 MW, 9340 GW h (2021)), with heating predominating (1650 MW; 6840 GW h (2021)). The most powerful heat-supply system in the country and in the world, in Reykjavik, is described: its capacity is 1150 MW and the length is 2230 km. Data are presented on the nonenergy use of geothermal water in fish farms, swimming pools, greenhouses, and carbon dioxide utilization plants. It is concluded that the experience of Iceland is especially significant for the development of geothermal energy in Russia. [ABSTRACT FROM AUTHOR]

Thermal stability is inevitable for upscaling and commercialization of third-generation photovoltaic devices. Heat generation in solar cells directly impacts their thermal stability. One of the rarely investigated heat-generation sources is tunneling recombination. Here, the heat generation via trap-assisted tunneling recombination (TATR) has been investigated for Cu2ZnSn(S,Se)2 or CZTSSe Kesterite thin-film solar cells using a coupled formulation and a simulation model developed by coupling the optical–electrical–thermal modules in the COMSOL simulation package. Heat generation from tunneling recombination was compared to heat from non-radiative Shockley–Read–Hall (SRH) recombination. All the simulations were performed for the three defects in the bulk of the CZTSSe and CdS layers: CuSn (0.55 eV), CuZn (0.1 eV), and SnZn (0.87 eV), which were chosen from the experimental data reported in the literature. Dark current density versus voltage and defect density were calculated and resulted in a higher tunneling recombination compared to the SRH recombination. The dark current density was also analyzed for a range of defect densities in the CdS partner layer, and for different recombination lifetimes, which resulted in a stronger dark current from TATR compared to SRH. Dark current in all the above analyses was obtained to be highest for CuSn. Finally, the heat-generation rate from the tunneling recombination was simulated versus voltage and cell thickness, and resulted in higher heat generation for the tunneling recombination, especially for the CuSn defect. This means that the contribution of the tunneling recombination to heat generation in thin-film solar cells is stronger than the non-radiative SRH recombination or interface recombination and could be a dominant thermal degradation mechanism in these cells, a finding that has often been neglected in the literature. [ABSTRACT FROM AUTHOR]

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For thermal diagnostics of friction determining the time dependence of frictional heat generation and, accordingly, the moment of friction in self-lubricating sliding bearings using temperature data, an algorithm for solving the inverse problem of heat conduction by iterative regularization is proposed. The iterative regularization algorithm for restoring the frictional heat generation function from temperature data using a three-dimensional model of the thermal process and taking into account the speed of the swinging movement of the shaft is implemented. An assumption was made about the uniform distribution of specific heat generation along the length of the bearing to simplify the formulation of the problem. The numerical solution of the model problem was carried out with the shaft oscillating with a frequency of 1 Hz and amplitude of 7.5°. The time step was chosen from the Courant condition and was 0.1 s. The full-time interval was divided into local ones when solving the inverse problem in order to avoid storing large arrays of temperature data at each iteration. The solutions at the junctions of local intervals were glued. A condition for stopping the iterative process of restoring the frictional heat generation function is proposed, taking into account the total error in temperature measurements and calculations using local intervals. Calculations show that the accuracy of restoring the function of the specific intensity of frictional heat generation using the developed algorithm for solving the inverse problem of 9.9% is commensurate with the accuracy of 3.8% of specifying temperature information. The developed algorithm for determining frictional heat generation using a 3D model of the thermal process can be used to determine the friction torque from temperature data in real self-lubricating sliding bearings operating in the oscillation mode. [ABSTRACT FROM AUTHOR]

This paper investigates the thermal-pseudo mechanical (TPM) model's residual stress prediction capability for its utility in developing friction stir processing (FSP). Specifically, two FSP tests under different processing conditions were conducted, and the corresponding simulations were carried out to verify if the TPM model can predict residual stresses for various tool radii and workpiece materials. The model successfully predicted residual stresses with an error less than 4% for one of the tests but failed to work for the other test. Further simulations under different FSP conditions proved that the TPM model works for cast aluminum alloys and wrought aluminum alloys. In addition, the large FSP tool used was found to be the reason for the model's failure on one of the tests. This indicates that there is a range of tool radii for which the TPM model is applicable. As a solution, this paper suggests modifications to the TPM model based on calibration to the FSP test temperatures. The resulting residual stress prediction is accurate and differs from the experimentally characterized stress values by only 6.5 MPa. The calibrated TPM model requires FSP to be carried out when using a tool with a different radius. Following that, the effect on residual stresses due to changes in the other process parameters, such as the tool traverse & rotation speeds and the clamping conditions, can be predicted. [ABSTRACT FROM AUTHOR]

Semi-solid lithium slurry battery is an important development direction of lithium battery. It combines the advantages of traditional lithium-ion battery with high energy density and the flexibility and expandability of liquid flow battery, and has unique application advantages in the field of energy storage. In this study, the thermal stability of semi-solid lithium slurry battery material system was investigated for the first time employing C80 micro-calorimeter. In this new electrode material system, the heat generation of the electrolyte is the decisive factor for its thermal stability. Then, the measurement of in-situ dynamic cycle heat generation of semi-solid lithium slurry battery indicated a lower heat generation than traditional lithium-ion battery. What's more commendable is that its electrochemical performance is basically the same as traditional lithium-ion battery. In addition, through the HPPC test, the mechanism of semi-solid lithium slurry battery cycle heat generation was explained. So, in this work, a preliminary evaluation on the safety and cycling stability of semi-solid lithium slurry battery is carried out. The electrochemical performance test affirms the application prospects of semi-solid lithium slurry battery, and the evaluation on the fire safety provides a reference for the future industrial applications of semi-solid lithium slurry battery. [ABSTRACT FROM AUTHOR]

Introduction: Heat is generated and transferred to the dentine-pulp complex during various dental procedures, such as from friction during cavity preparations, exothermic reactions during the polymerisation of restorative materials and when polishing restorations. For in vitro studies, detrimental effects are possible when intra-pulpal temperature increases by more than 5.5°C (that is, the intra-pulpal temperature exceeds 42.4°C). This excessive heat transfer results in inflammation and necrosis of the pulp. Despite numerous studies stating the importance of heat transfer and control during dental procedures, there are limited studies that have quantified the significance. Past studies incorporated an experimental setup where a thermocouple is placed inside the pulp of an extracted human tooth and connected to an electronic digital thermometer. Methods: This review identified the opportunity for future research and develop both the understanding of various influencing factors on heat generation and the different sensor systems to measure the intrapulpal temperature. Conclusion: Various steps of dental restorative procedures have the potential to generate considerable amounts of heat which can permanently damage the pulp, leading to pulp necrosis, discoloration of the tooth and eventually tooth loss. Thus, measures should be undertaken to limit pulp irritation and injury during procedures. This review highlighted the gap for future research and a need for an experimental setup which can simulate pulp blood flow, temperature, intraoral temperature and intraoral humidity to accurately simulate the intraoral conditions and record temperature changes during various dental procedures. [ABSTRACT FROM AUTHOR]

The study of reversible and irreversible heat generation of lithium-ion batteries at different C rates is important for designing thermal management system. Galvanostatic intermittent titration technique is used to determine the overpotential of different SOC (state of charge) or SOD (state of discharge) of commercial lithium iron phosphate pouch cells. The reversible and irreversible heat generation of the battery is calculated based on the entropy change and overpotential. It is found that when the lithium iron phosphate battery is charged, reversible heat first manifests itself as heat absorption, and then soon as exotherm after around 30% SOC, while the reverse for discharge. The total heat generation of lithium iron phosphate batteries during charging is higher than that during discharging. The relative contribution of irreversible and reversible heat generation at low and high rates are different. At 0.1 C rate, the maximum proportion of qrev is about 70%, while at 1 C rate, the maximum proportion of qrev is about 25%. [ABSTRACT FROM AUTHOR]

A theoretical investigation for internal heat generation, suction/injection, diffusion-thermo and nano-particle volume fraction on a chemically reacting hydro-magnetic flow of Cu–water nano-fluid over a semi-infinite vertical surface is presented in this article. The surface has a uniform velocity which is placed in a saturated porous medium. Under thermal equilibrium state, here we consider that the nano-particles are of uniform shape and size. The small perturbation technique is utilized to solve the boundary layer equations, and the solutions are assumed to be oscillatory type. The significant outputs are presented via figures to explain the effects of different controlling variables on the velocity, temperature, concentration, shear stress and rate of heat transfer profiles. As the conductivity of Cupper particles are higher than those of water-based particles, and significantly it is found that the flow velocities are accelerated for the impact of diffusion-thermo/Grashof/internal heat generation. Increasing porosity parameter decelerate the flow velocity for both nano-fluid and base fluid, whereas enhance the temperature for the radiation parameter. For the impact of free convection and diffusion-thermo, growth values of flow velocity are detected for nano-fluid (Cu ) than the base fluid (water). Furthermore, application of Cu nano-particles can be used in conductive coatings, medical devices, anti-biotic, and textiles. Comparison with previously published works in the limits shows excellent agreement. [ABSTRACT FROM AUTHOR]

This study introduces a novel computational technique aimed at enhancing fluid heat transfer capabilities through the integration of hybridized nanoparticles into a fluid matrix, resulting in a graphene–copper water-based hybrid nanofluid. The research focuses on modeling and solving the complex dynamics of radiative hybrid nanofluid flow across a permeable convective surface with simultaneous heat generation. Utilizing a similarity transformation, the model is simplified and subsequently solved using a MATLAB numerical solver. Dual solutions are identified, and their stability is confirmed through rigorous stability analysis. To optimize heat transfer enhancement, the study employs response surface methodology (RSM) to refine key parameters—specifically thermal radiation, heat generation, and the Biot number—with the goal of achieving maximum heat transfer efficiency. Findings indicate a notable increase in heat transfer efficiency when employing a 2% volume fraction of copper in the hybrid nanofluid compared to lower concentrations (1–1.5%). Optimal conditions for the skin friction coefficient and flow bifurcation delay are identified which demonstrates effective control over fluid dynamics. Additionally, strategic adjustments in heat generation and nanoparticle volume fractions lead to significant reductions in fluid temperature, thereby enhancing thermal management efficiency. This research significantly advances the understanding of the thermal performance of hybrid nanofluids under dynamic conditions and provides practical insights for optimizing heat transfer in industrial applications. [ABSTRACT FROM AUTHOR]

This study investigates the theoretical knowledge about the absorption cross-section, heat release, and temperature change of liquid Cs-core and various shell materials by employing the Mie theory. The present work was carried out with varying Cs-core sizes, viz., 10 nm, 15 nm, 20 nm, 25 nm, and 30 nm with a fixed 5 nm shell thickness of Ag and Au, Al and its oxide (Al2O3), and Cu and its oxide (Cu2O) in the presence of the surrounding environment (i.e., water). The localized surface plasmon resonance (LSPR) peak position emerges between 299 and 1132 nm wavelengths, and the observed spectra are tuned in the vicinity of the ultraviolet (UV) and infrared (IR) domains of the electromagnetic (EM) spectrum. The maximum absorption cross-section was revealed for the 30 nm Cs-core at resonance wavelengths of 639 nm (σabs ≈2.41E − 14 m2) with a Cu shell thickness. The maximum temperature and absorption power at the surface of the nanoparticles were observed at 9.21 °C and 2476 nW for Cs@Cu at 629 nm wavelength in the water environment. Moreover, absorption cross-section spectra and heat power increased with increasing core-sizes. The E-field enhancement was highest when Cs NPs were placed in the core rather than the shell material, and the E-field values increased with decreasing Cs-core sizes. These results show that the intensity and LSPR position of peaks, heat generation, and temperature elevation are strongly influenced by varying the Cs core sizes with various shell materials. The observed results can have potential applications in thermoplasmonic devices, sensing, cancer therapy, photocatalytic activity, and Surface-enhanced Raman spectroscopy (SERS). [ABSTRACT FROM AUTHOR]

Thermoset composites are strong candidates for large-scale material extrusion additive manufacturing (AM). However, uncured thermoset composites become unstable as print height increases. Here, chemical initiation of vinyl ester immediately before deposition was used to suppress collapse and enable large-scale thermoset printing. Structural stability was assessed by printing thin walls at various layer times and monitoring thermal gradients with an infrared camera. Stable printing was observed at a layer time of 4.50 min, approximately half the gel time of the material (8 min). Self-weight collapse occurred at short layer time (0.68 min), whereas warpage occurred at long layer time (6.50 min). A new behavior was discovered at intermediate layer time (2.25 min) where the heat generated by the reaction causes new, un-gelled layers to flow. Forced convection eliminates this behavior, stabilizing the 2.25-min layer time print. These findings motivated development of a less exothermic material system, which was used to print a large-scale mold and demonstrate the value of this understanding. By presenting these challenges of large-scale reactive thermoset AM for the first time, this work motivates focused studies of the complex interplay between rheological, thermal, and chemical behaviors to improve the feasibility of large-scale thermoset AM. Tensile properties of the printed material were also measured. Longitudinal and transverse elastic moduli are 3.79 and 2.95 GPa, respectively, and corresponding tensile strengths are 36.11 and 18.83 MPa. The glass transition temperature is 93.13 °C. [ABSTRACT FROM AUTHOR]

In Mexico, the possibility to exploit orange peels or sugarcane straw to generate heat has not been fully explored, even though they are major agronomic wastes generated in Mexico. Therefore, this paper aims to assess the heat generation's environmental and economic performance from these feedstocks in a fruit-processing facility located in Veracruz, Mexico. The environmental performance was assessed through the life-cycle assessment methodology, while the economic performance was estimated through the total levelized cost of energy (TLCE) considering two scenarios: (1) a base scenario where orange peels are burnt to produce process steam, and (2) a second scenario where sugarcane straw is co-fired with it. Both scenarios assume to partially displace heavy-fuel–oil (HFO) for steam generation. Results indicate that the impacts of the use of residual biomass-based heat on the potential global warming, ozone layer depletion, marine aquatic ecotoxicity, and cumulative energy demand are 34–63% lower than when using HFO and decrease the TLCE by 18–21%. However, there is also an increase in other environmental impact categories such as human toxicity, photochemical oxidation, or eutrophication. The use of orange from organic farms improves the environmental results in some of these categories. The drying and combustion of the biomass, as well as the waste treatment, are the major contributors to the environmental impacts. On the other hand, capital and fuel costs are the major contributors to TLCE. Overall, the use of orange peels and sugarcane straw to generate heat is attractive from the environmental and economic point of views. [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental investigations of the heat generation and microstructure evolution during the friction stir processing (FSP) of the SnSb11Cu6 alloy. The Triflute tool was used for modification; the process was carried out using two rotational speeds of the tool: 280 and 560 RPM and a constant linear speed of 355 mm/min. Microstructure studies were performed employing the techniques of light microscopy and scanning electron microscopy along with analysis of the chemical composition of micro-areas. Additionally, the phase composition was investigated by means of the X-ray diffraction method, and electron backscatter diffraction (EBSD) analysis and hardness testing were performed before and after FSP modification. Furthermore, measurements of the temperature directly on the modified surface by means of a thermal imaging camera and the temperature in the modified zone with a thermocouple system were performed. It was proved that using FSP to modify the SnSbCu alloy promotes refinement and homogenization of the microstructure, as well as improvement of the hardness. The hardness of the starting material was 24 HB, and after FSP, the hardness increased and amounted to, respectively, 25 and 27 HB after processing at 280 and 560 RPM. The microstructure in the stir zone is formed by the dynamic recrystallization (DRX) process and consists of almost equiaxed tin-rich matrix grains with a size of approx. 5–30 µm and fine particles of Cu6Sn5 and SnSb phases. The temperature distribution in the FSP zone is not uniform and changes in a gradient manner. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries should continuously be operated at the optimum temperature range 15 ∼ 40 ∘ C for the best performance. Surface temperature monitoring is critical for the safe and efficient operation of the battery. In this study, initially, the electrical parameters of the battery are determined by applying a second-order equivalent circuit model. This model then is integrated with a thermal model based on the temperature dependent behavior of the electrical parameters and the heat generated. The input parameters to the electro-thermal model include the current, the ambient fluid temperature and the output parameters include the terminal voltage, state of charge, cell core temperature and cell surface temperature. In this research, the entropic coefficient and battery thermal parameters have been taken into consideration concurrently, which will lead to both saving plenty of time and cost compared to other methods. The accuracy of the suggested analytical approach for estimating the surface temperature and the amount of heat generation is validated with the pulse-rest tests of an 18,650 cylindrical lithium-ion battery with a nominal capacity of 2600 mAh at three different ambient temperatures and three charge/discharge current rates. The comparison of results indicate that the maximum error of the proposed algorithm is about 0.6 K under a wide range of test conditions. [ABSTRACT FROM AUTHOR]

Heat generation has been recognized as a detrimental factor to the performance stability of thin-film solar cells. A major part of this heat generation is due to recombination of defects located at near mid-gap level and interface. However, the other defects (acceptor/donor) located at different energy levels in the absorber layer of a solar cell will also contribute to recombination via shallow or deep defect levels and thus to heat generation in the cell. Nevertheless, there is no report in the literature on investigating the heat generation due to recombination into defects at shallow or deep levels in the cell. This simulation study focuses on the analysis of heat generation due to defects located at different energy levels in the bulk of a Cu2ZnSn4SxSe4-x (CZTSSe) based thin-film solar cells. A strong simulation model has been developed by coupling the optical, electrical, and heat modules in the COMSOL simulation package. Different defect levels with shallow or deep energy (known by experimental data reported in the literature) have been inserted in the semiconductor module and the heat generation due to non-radiative recombination to these levels has been calculated, separately. To calculate the recombination at these deep/shallow levels, an additional recombination component has been added in COMSOL, in addition to conventional Shockley–Read–Hall recombination (for mid-gap defects). It is concluded that the deep energy levels close to the mid-gap level generate (5%) more heat compared to shallow defects located at energy levels close to valence or conduction bands. Fill factor drops 11% due to defect closer to mid-gap which represents the cell instability due to higher heat generated due to this defect level. [ABSTRACT FROM AUTHOR]

Nowadays, hybrid friction stir welding of high strength/melting point alloys like steels is an emerging technique to improve the material flow and reduce the welding forces. This work carried out the experimental and numerical investigations on friction stir welding (FSW) and plasma-assisted hybrid FSW (P-FSW) of AISI 1018 low carbon steel plates. A three-dimensional finite element (FE) transient thermal model based on the DFLUX subroutine was developed using the FE software package ABAQUS 6.14. The moving coordinate-based surface heat flux distribution for the tool shoulder and volumetric heat distribution for the tool pin was considered. The Gaussian distribution of heat flux was applied in the P-FSW to model the preheating source. The transient thermal profiles and stir zone isotherms of the FE models were correlated fairly well with the experimental results of the FSW and P-FSW. The influence of tool rotational speed, traverse speed, plasma radius, and the gap between tool shoulder and plasma preheating source on comparative thermal history was investigated. It was observed that the plasma assistance in FSW significantly enhanced the heat generation than the normal FSW. Furthermore, the temperature in P-FSW increased by enhancing the plasma radius and reducing the gap between the tool shoulder and the plasma preheating source. The plunging force was reduced by around 20–25% using the plasma preheating ahead of the FSW tool. P-FSW joint experienced a comparatively higher weld strength, which can be attributed to the more grain refinement in P-FSW than the FSW under the higher heat generation. [ABSTRACT FROM AUTHOR]

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The intention of the current research is to address the conclusion of non-isothermal heterogeneous reaction on the stagnation — point flow of SWCNT — engine oil and MWCNT — engine oil nanofluid over a shrinking/stretching sheet. Further, exemplify the aspect of heat and mass transfer the upshot of magnetohydrodynamics (MHD), thermal radiation, and heat generation/absorption coefficient are exemplified. The bvp4c from Matlab is pledged to acquire the numerical explanation of the problem that contains nonlinear system of ordinary differential equations (ODE). The impacts of miscellaneous important parameters on axial velocity, temperature field, concentration profile, skin friction coefficient, and local Nusselt number, are deliberated through graphical and numerically erected tabulated values. The solid volume fraction diminishes the velocity distribution while enhancing the temperature distribution. Further, the rate of shear stress declines with increasing the magnetic and stretching parameter for both SWCNT and MWCNT. [ABSTRACT FROM AUTHOR]

We report here the heat generation and impedance characteristics of prototype 18650-sized sodium-ion cells using pristine Na3V2(PO4)3 (P-NVP) and modified Na3.2V1.8Zn0.2(PO4)3 (M-NVP) cathodes, hard carbon (HC) anode and an ether-based non-flammable electrolyte, 1 M NaBF4 in tetraglyme. Comparison of calorimetric studies performed on 18650-sized cells reveals lower heat generation in M-NVP versus HC compared to P-NVP versus HC owing to low internal resistance achieved as a result of Zn2+ doping in M-NVP. Both irreversible heat generation arose due to internal resistance and reversible heat generation caused by entropic changes in the electrode materials are elucidated. Furthermore, variation in subcomponents of internal resistance in both 18650-sized full cells and CR2016-sized half-cells is analysed by fitting electrochemical impedance spectra into equivalent circuit models. Individual contributions of anode and cathode to the impedance characteristics of the cells are determined by analysing impedance data of the half-cells using the distribution of relaxation times method. The results reveal lower diffusion resistance, as well as charge transfer resistance in M-NVP cells compared to P-NVP counterpart, accounting for the observed lower total internal resistance in M-NVP versus HC and thus lower heat generation in M-NVP versus HC cell than P-NVP versus HC cell. [ABSTRACT FROM AUTHOR]

The friction stir spot welding test was designed to measure the coefficient of friction on the tool-workpiece interface under different tool rotational speeds. The boundary velocity of the workpiece material was calculated based on the stress state of the material on the interface. An integrated computational fluid dynamics (CFD) model of friction stir welding (FSW) was established based on the coefficient of friction and boundary velocity of matrix to simulate heat and mass transfer. A more realistic boundary velocity distribution was acquired. A method was introduced to predict strain along a streamline by integrating the strain rate along with the streamline's reverse. The nephogram of strain on the transverse cross-section of weldment displays that strain at the advancing side (AS) is more significant than that at the retreating side (RS), and strain increases as the distance from the shoulder surface decreases. Strain in some regions can be tremendous if the material flows through the rotation flow zone. Wall heat flux on the tool-workpiece interface at RS is more significant than AS. The maximum temperature was observed at the front part of RS. The model is validated since the predicted temperature profile agrees well with corresponding experimental results. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To get deep insight into the interaction mechanism of ultrasound with the plastically deformed metal in the ultrasonic-assisted friction stir welding (UaFSW) process, the ultrasonic effect on the heat generation and material flow is quantitatively analyzed. The Coulomb friction model is modified via considering both the vibration direction and intensity of the exerted ultrasound, and a bidirectional coupling model of ultrasonic field, thermal field, and material flow state is used to analyze the antifriction mechanism at the interfacial tool/workpiece contact state in UaFSW. It is found that in UaFSW process, the ultrasonic direction affects the frictional stress distribution, while the ultrasonic intensity determines the antifriction strength. Only when the welding process parameters are in suitable range can the ultrasonic field both promote the flow velocity magnitude and broaden the flow range. For the study case, the friction heat generation at the tool/workpiece contact interface decreased by 24%, and the total plastic heat generation increased by 18%. Due to the dual effects of ultrasonic antifriction and acoustic softening on the interface, the total welding heat is slightly reduced. The calculated results are experimentally validated via comparing thermal cycles and thermo-mechanically affected zones with experiments. [ABSTRACT FROM AUTHOR]

There is a crucial necessity for enhancing the efficiency of the solution of problem describing the non-Newtonian fluid flow over a stretching sheet to improve proficient the mechanism of heat transfer in numerous practical applications. For this aim, an efficient spectral collocation method is implemented in this paper to present the numerical solution for the flow and heat transfer of a non-Newtonian Casson model together with the presence of viscous dissipation and variable heat flux, with reference herein to the slip velocity and the heat generation or absorption condition. The absence of the magnetic field phenomenon in some studies is an essential restriction in the processes of development for the energy-efficient heat transfer mechanism that is desired in numerous industrial applications. So, the magnetic field is implemented here for this Casson model. Industrially, this type of fluid can describe the flow of blood in an industrial artery, which can be polished by a material governing the blood flow. The spectral collocation method based on Chebyshev polynomials of the third kind is employed to solve the resulting system of ODEs which describes the problem. This scientific study encompasses many parameters such as unsteadiness parameter, slip velocity parameter, Casson parameter, local Eckert number, heat generation parameter, and the Prandtl number. From this study, it has been consummated that the Casson model is superior to others that are much used as the industrial fluid. Finally, the given results show that the spectral collocation method is an easy and efficient tool to investigate the solution for such models. [ABSTRACT FROM AUTHOR]

This analysis explores stagnation point in Jeffery liquid flow over a stretchable cylinder. Heat and mass transfer are investigated through Cattaneo–Christov model with double stratification, heat source and thermal relaxation. Moreover, the flow of liquid is caused by stretchable cylinder. Cylindrical coordinates are used for mathematical formulations. The acquired boundary layer problems for stretchable cylinder are dealt through homotopy analysis method. Results of variables appeared in governing equations are disclosed through graphs for flow, temperature, concentration and skin friction. The findings of the study show that higher values of ratio parameter and Deborah number in terms of relaxation time reduce magnitude of drag coefficient while reverse trend is noted for larger Deborah number in terms of retardation time and curvature parameter. Comparison of present work with previous published date is presented. [ABSTRACT FROM AUTHOR]

Kesterite thin-film solar cells with abundant earth materials have attracted the attention of research groups and have reached over 12% efficiency so far. Cu(Zn, Te)(S, Se) 2 (CZTSSe) are emerging materials as an alternative for CdTe and CIGS chalcopyrite materials. However, the low performance of these devices compared to perovskite solution-processed materials has reduced their research popularity and commercialization of these devices. Heat generation and dissipation in these devices must be investigated as effective phenomena in either morphology and performance parameters of the cell. Here, a systematic coupled Opto-electro-thermal model has been developed to calculate the impact of the thermodynamic operation on the carrier transport in the structure of CZTSSe thin-film solar cells. The simulation considers the heat generation mechanisms in the structure of CZTSSe devices which are the main thermal losses as well. Five heat generation sources have been classified in the heterostructure of a conventional CZTSSe solar cell including intrinsic loss via Joule and Peltier heats (separately for electrons/holes), non-radiative recombination (including Auger recombination), surface recombination, and thermalization heats. We discussed the temperature distribution across the cell for different voltages. The impact of every heat generation factor on the current and voltage of the cell has been simulated and the heat generation density of each factor has been calculated and mapped in 3D for comparison. [ABSTRACT FROM AUTHOR]

A systematic approach is used to determine a new technical solution for material plastic deformation making it possible to separate the main and essential research features and to substantiate the solution adopted. Creation of an engineering assemblage is conducted on the basis of using a criterion for constructing metal plastic deformation classification and addition of intensification factors. Thermal effects during friction and impulse deformation are considered in order to select a new direction of research. The influence of a temperature effect under conditions of high speed deformation is established on the basis of metal forming process mechanics and analysis of experimental data. A classification is developed for processes that combine simultaneous force and heat effects through a deforming tool. The problem of determining the temperature effect during impulse deformation is found and confirmed experimentally. A new direction of plastic deformation processes intensification is determined that combines pulsed force action with a thermal effect in a deformable body surface layer. A new method of impulse friction hardening is proposed. [ABSTRACT FROM AUTHOR]

A mathematical model is used to discuss a comparative study of AA7072 (nanofluid) and AA7072/AA7075 (hybrid nanofluid) flow through endoscope. For this evaluation, AA7072 (which is the combination of Al (98 %) and Zn (1 %) mixed with metals Si, Fe and Cu) and AA7075 (which is the mixture of Al (90 %) , Zn (6 %) , Mg (3 %) and Cu (1 %) mixed with metals Si, Fe and Mg) are considered as nanoparticles and water as a base fluid. The inner cylinder is endoscope (rigid and fixed) moving with constant velocity (V) , while the external cylinder is sinusoidal (wave moving down to its boundaries) like the shape of artery in the form of concentration and relaxation phenomena. Low Reynolds number and long wavelength estimation is applied for analytic solution. The resulting nonlinear PDEs are transformed into ODEs by perturbation technique. After this, we compare graphically the behavior of nanofluid and hybrid nanofluids for velocity profile, temperature profile, friction forces on inner and outer cylinders, pressure gradient and pressure rise for different values of solid volume fractions and inner cylinder radius. [ABSTRACT FROM AUTHOR]

The main goal of the current article analyzed the influence of MHD flow of micropolar fluid via exponentially curved stretching surface. Heat transfer analysis is discussed with the impact of thermal radiation and Joule heating. For mathematical model curvilinear (u, v, r and s) is taken for governing flow problem. Viscous dissipation is also considered. Exponential similarity variables are used to transform partial differential equations to ordinary differential system. (ODEs). Numerical techniques have been used to solve the nonlinear ODEs. Effect of various physical variables like material parameter (K 1 = 0.1 , 0.2 , 0.3 , 0.4 , 0.5) , radius of curvature ( δ = 1 , 2 , 3 , 4 , 5 ), magnetic parameter ( M = 0 , 0.1 , 0.2 , 0.3 , 0.4 ), radiative parameter ( R d = 1.0 , 2.0 , 3.0 , 4.0 , 5.0 ), heat generation parameter (Q = 0, 0.1, 0.2, 0.3, 0.4), surface friction, couple stress and surface temperature on the flow of velocity, temperature field and microrotation velocity has been examined through graphs. A good agreement of the present work has been noticed with a previous published result. [ABSTRACT FROM AUTHOR]

Applying the electric field to a fluid flowing on an infinite vertical plate is the most recent technique used for studying fluid movement. This technique is known as electro-osmotic flow (EOF). Therefore, the core aim of the present research work is to examine the time-dependent electro-osmotic flow of viscoelastic fluid on a vertical flat plate together with the effects of heat generation and chemical reaction. The classical system of governing equations has been fractionalised by means of Caputo–Fabrizio’s time-fractional derivative. Governing equations have been non-dimensionalised by using relative dimensionless quantities. The exact solutions for the momentum, temperature and concentration equations have been developed by implementing the Laplace transform technique. For graphical analysis, the solutions have been plotted against the inserted parameters using the computational software Mathematica. It is interesting to mention that the time-fractional model provides more than one fluid layer for the analysis of the fluid motion, heat distribution and mass concentration, which is not possible by assuming the classical mathematical model. It is also very important to mention that the velocity profile shows declination for greater values of electro-osmotic parameter Es. [ABSTRACT FROM AUTHOR]

The primary focus behind this research work is to unfold the heat and mass transfer characteristics of peristaltic transport of hydromagnetic couple stress fluid through a porous medium in an inclined channel of asymmetric kind. Consideration of both Dufour and Soret effects is one of the key factors of this investigation. Simultaneous convective conditions of mass and heat transfer are satisfied by the channel walls. Beneath the presumptions of small Reynolds number along with long wavelength, the governing two-dimensional coupled differential equations are simplified after incorporating dimensionless variables. To calculate the pressure difference, the technique of numerical integration has been employed. Graphical demonstrations for velocity, temperature, concentration profiles have been sketched out under the influence of pertinent flow parameters. Pumping characteristics and trapping phenomenon for some particular kind of waveshapes are also highlighted through contour plots. Noteworthy findings are that near the center of the channel the maximum value of the temperature is attained due to the intensification of heat generation parameter. Also, Dufour number tends to enhance the temperature of the fluid, whereas Soret effect results in a downfall in the concentration field. Heat and mass transfer Biot numbers lead to an elevation in the concentration and temperature profiles, respectively. It is also perceived that a reduction in concentration takes place due to the presence of destructive kind of chemical reaction while a reverse trend is being followed during a chemical reaction of constructive kind. Moreover, both the pressure gradient as well as pressure difference act as increasing functions of the angle of inclination of the channel. Additionally, the general propensity of couple stress fluid parameter is to diminish the volume of the trapped bolus. [ABSTRACT FROM AUTHOR]

Joining the advanced high-strength steels and conventional steels is a critical issue for the manufacturing of lightweight vehicles. Resistance element welding (REW) is an emerging joining method for dissimilar metals and alloys by applying an auxiliary rivet-like resistance element in resistance spot welding (RSW). In this study, an electrical-thermal-mechanical coupled REW model for high-strength dual-phase (DP) steel and Q235 steel was developed by considering contact resistances as functions of temperature and surface contacting area. The results show that the welding element in REW serves to concentrate the current flow and thus Joule heat generation at the faying interface between the element and workpiece. For welding DP600 and Q235 workpieces with a small thickness ratio (≤0.4) or a high electrical resistivity ratio (≥3), REW could effectively mitigate nugget shifting between workpieces and reducing the thermal excursion to the electrode compared to RSW. Adding well-designed insulation layers in REW could further concentrate the current within the welding element, and enables a large-sized nugget at a lower current. This study is significant because it provides a better understanding of the nugget development under the electrical-thermal-mechanical interaction at interfacial contacts in REW and contributes to its further advance. [ABSTRACT FROM AUTHOR]

In this paper, we aim to investigate the heat generated during friction stir lap welding in polypropylene sheets. In this method, the generated heat significantly depends on the tool's rotational and linear speed, geometry, and tilt angle. Heat analysis and measurement during welding are performed numerically to validate the experimental results. A 3-D symmetric Finite Element (FE) model was created to estimate the generated and distributed heat. As is shown, the heat is mainly generated around and underside the tool due to the high friction between the rotating tool and the workpiece. This paper provided a good intuition on the generated and distributed heat during the FSW process, which can be considered a reference to produce optimum and high-quality products with fewer tests. Therefore, in this paper, the effect of a number of parameters on the generated heat during the welding process is studied experimentally and statistically and simulated in three different levels. The obtained results demonstrated a significant relationship between the properties and process parameters using analysis of variance (ANOVA) and response surface method (RSM) (Box-Behnken). Moreover, the results revealed that the effect of parameter interactions could be evaluated using the proposed mathematical model by analyzing the presented plots. In addition, the results from the simulated model using finite element software and Altair's HyperWorks confirmed the mathematical model estimations and the experimental results. The created model can successfully predict 92% of the welding joint temperature using the conditions and materials proposed in this paper. The results of the simulation analysis were validated and compared with the experimental tests, indicating a temperature difference of approximately 6%. The most effective parameter in heat generation is the rotational speed of the tool, which is responsible for up to 70% of the overall heat. Tool's geometry (15%), traveling speed (11%), and tilt angle (4%) are the other parameters effective in generating heat in the process, in respective order. [ABSTRACT FROM AUTHOR]

Nanoliquids via diffusing less quantity of nanometer-sized elements in base liquids can extraordinarily upsurge heat transport along with thermal functioning of heat exchanging systems. Such liquids are utilized in various fields for illustration liquid fuel, energy storage and absorption, heat-mass transport and lubricating materials. Thus, we aimed to formulate and scrutinize the nanoliquid hydromagnetic flow by permeable convected cylinder. Rheological expressions of Jeffrey liquid are considered to develop flow formulation. Buongiorno model featuring thermophoresis and Brownian diffusions is under consideration for modeling and analysis. Nonlinear version of thermo-solutal buoyancy forces is also a part of this study. Robin conditions, dual stratification and radiation effects are accounted to capture the analyze the heat transport characteristics. Homotopy concept yields convergent solutions of modeled non-linear differential systems. In addition, dimensionless factors are elaborated in detail through graphical and tabular results. We examined reduction in liquid temperature along with concentration subjected to higher thermal/concentration stratification factors. [ABSTRACT FROM AUTHOR]