Search

This study explores the effects of a first-order slip boundary condition on the magnetohydrodynamic flow and heat transfer in a Casson-based hybrid nanofluid containing copper oxide (CuO) and graphite oxide (GO) nanoparticles in methanol (CH 3 OH) . To address the critical need in advanced cooling and thermal management, the research delves into the complexities of thermal radiation, viscous dissipation, and Joule heating. To ensure comprehensive validation and robustness of the findings, we employed both the bvp4c and Keller–Box numerical methods, each chosen for its strengths in different aspects of the model problem. This dual-method approach, detailed in our comparative analysis section, enhances the scientific rigor of our results. Using an effective similarity transformation, complex governing equations are transformed into a manageable set of ordinary differential equations, which are then numerically solved. Our findings reveal that hybrid nanofluids offer enhanced thermal properties and flow adjustability compared to single-nanoparticle fluids, with significant impacts of radiation and magnetic field on the thermal boundary layer. These insights not only advance theoretical knowledge but also have substantial practical applications in fields such as medical sciences, opto- electronics, and energy systems, establishing a new benchmark in fluid dynamics and materials science for thermal management technologies. [ABSTRACT FROM AUTHOR]

The study analyzes the unique behavior of two-phase flows when incorporating nanofluids containing aluminum trioxide (Al2O3) and copper (Cu) nanoparticles in a vertical channel. The main goal is to investigate the behavior of airnanofluid mixtures in this setting, with potential implications for industrial and exploration applications. Research in this area could provide valuable insights into the dynamics of these flows and their impact on heat transfer, fluid dynamics, and material science. This study includes an analysis of upwelling dynamics, the effect of fluid characteristics on bubble growth, and the system's thermal efficiency. Using numerical and quantitative visualization techniques, we seek to understand the behavior of these particles at the interface between the liquid and gas phases by integrating Al2O3 and Cu nanoparticles into the VOF approach. Because of their superior thermal conductivity, copper nanoparticles have a higher volumetric density and provide more efficient heat transfer, leading to quick and efficient thermal dissipation. Smaller nanoparticles offer an increased surface area-to-volume ratio, which improves heat transfer capabilities and ensures uniform heat dissipation throughout the material. Consequently, copper nanoparticles emerge as the preferred choice for applications necessitating high thermal transfer and optimal performance. These results significantly impact the design of more efficient heat exchangers and optimize recovery techniques by elucidating the interactions between these nanoparticles and the surrounding fluids. Furthermore, the selection of smaller copper nanoparticles further amplifies thermal transfer, maximizing performance across diverse applications. [ABSTRACT FROM AUTHOR]

The research of heat and mass transfer enhancement is influenced by several physical effects such as thermal conductivity, heterogeneous catalytic reaction, heat source/sink, thermal radiation and suction/injection, and is a significant area of study, particularly in the field of applied materials science, nanotechnology and mechanical engineering. The main objective of this research is to analyze and explore the heat and mass transfer of a novel ternary hybrid nanofluids binary nanofluid flow while considering the influences of the control parameters mentioned earlier. The model is developed for Hamilton and Crosser to analyze the radiation mechanism in a fluid system subjected to a Riga wedge. Due to the upgraded thermal transportation, the novel ternary hybrid nanofluids (THNs) show great potential in addressing these difficulties because of their significant properties, which include enhanced thermal conductivity, convective thermal transport and the ability to improve autocatalysis reactions. The governing model equations and boundary conditions are nondimensionalized by introducing suitable similarity transformations. Thereafter, the computational Chebyshev collocation spectral technique implemented in the MATHEMATICA 11.3 environment is used to calculate the numerical solution. The THNs demonstrate an efficiency rate of about 2.79%, with a minimum efficiency rate of 3.27%. It has been revealed that heat generation and solar radiation parameters are significant physical features for enhancing heat transfer processes. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the thermodynamic reactions of thermoelastic materials by utilizing a modified mathematical fractional thermoelastic model. This model combines a fractional derivative with Rabotnov's exponential kernel and the idea of a two-phase delay, which makes it possible to show thermoelastic behavior more accurately. The model was utilized to investigate an unbounded material with a spherical cavity subjected to a decreasing and shifting heat flux on its inner surface. The problem was solved using analytical approaches, with a strong focus on the Laplace transform. The transform was numerically inverted to provide time-domain results. The study presented graphs that compared the outcomes of utilizing a single kernel fractional derivative with the results obtained using the Rabotnov kernel and fractional order. These graphs showed how the Rabotnov kernel and fractional order affected the physical fields under investigation. This novel theoretical framework has the potential to be advantageous in diverse domains, including engineering, solid mechanics, and materials science. [ABSTRACT FROM AUTHOR]

The thermionic vacuum discharge method is very effective in that the films obtained using this technology are characterised by a very high degree of adhesion, density and purity because the deposition technique is carried out in high, very high or, if possible, in ultra-very high vacuum conditions with no gas present. When the substrate is placed in vacuum, no heat transfer particles are present, the substrate being heated only by the ion incident on the surface. This advantage recommends the TVD method for deposits on plastics or other thermally sensitive materials. Additionally, this slow heat transfer reduces energy loss, making the deposition method industrially competitive. The paper aims to present theoretical aspects of this type of discharge, compared to typical or more popular plasmas but also to present the achievements of this method and its utility in the thin films production, layers that have specific imposed properties. The practical depositions and applications presented are in the nuclear fusion-related material science and also for obtaining materials for granular structures, used as magneto-resistive coatings. [ABSTRACT FROM AUTHOR]

The dominant characteristics of hybrid nanofluids, including rapid heat transfer rates, superior electrical and thermal conductivity, and low cost, have effectively piqued the interest of global researchers. The current study will look at the impacts of a silver and cobalt ferrite-based hybrid nanofluid with MHD between a revolving disk and cone. The collection of partial differentiable equations is converted into a set of ODEs via similarity transformations. We used the Homotopy analysis approach from the BVPh 2.0 package to solve the ordinary differential equations. The volume proportion of nanoparticles increases and the temperature distribution profile also increased. It is more efficient for metallurgical, medicinal, and electrical applications. Furthermore, the antibacterial capabilities of silver nanoparticles might be used to restrict the growth of bacteria. A circulating disc with a stationary cone has been identified to provide the optimal cooling of the cone disc device while maintaining the outer edge temperature constant. This study's findings might be useful in materials science and engineering. The usage of hybrid nanofluid in heat transfer and heat pumps, coolants in manufacturing and production, producing cooling, refrigerators, solar thermal collectors, and heating, air conditioning, and climate control applications are only a few examples. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology 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.)

A recent article in the National Science Review discusses the importance of thermal management in high-power electronic devices and the role of thin liquid film boiling on micro-structured wicking surfaces in enhancing heat transfer effectiveness. The article presents a high-fidelity model developed by researchers at Huazhong University of Science and Technology to predict both heat transfer coefficient (HTC) and critical heat flux (CHF) during liquid film boiling. The model takes into account evaporation and nucleate boiling processes and has been validated with experimental data. The researchers believe that this model can be used to design and optimize structured surfaces for improved thermal management in electronic, energy, and space systems. [Extracted from the article]

Simulating the heat transfer in a composite material is an important topic in material science. Difficulties arise from the fact that adjacent materials cannot match perfectly, resulting in discontinuity in the temperature variables. Although there have been several numerical methods for solving the heat-transfer problem in imperfect contact conditions, the methods known so far are complicated to implement, and the computational times are non-negligible. In this study, we developed a ResNet-type deep neural network for simulating a heat transfer model in a composite material. To train the neural network, we generated datasets by numerically solving the heat-transfer equations with Kapitza thermal resistance conditions. Because datasets involve various configurations of composite materials, our neural networks are robust to the shapes of material-material interfaces. Our algorithm can predict the thermal behavior in real time once the networks are trained. The performance of the proposed neural networks is documented, where the root mean square error (RMSE) and mean absolute error (MAE) are below 2.47E-6, and 7.00E-4, respectively. [ABSTRACT FROM AUTHOR]

The heat conduction of solids has always been an important issue in materials science. Some structure-ordered crystals deliver heat transfer characteristics similar to amorphous solids, which endow such crystals with glass-like thermal properties that are attractive and promising in numerous applications. Here, the glass-like thermal behavior as a "three-stage" type inside rare-earth (RE) doped alkaline earth fluoride crystals is reviewed. By modeling and analyzing the thermal conductivity of RE doped CaF2 crystals as a function of temperature and doping concentration, the mechanism of glass-like heat conduction behavior emerging from RE doped fluoride crystals is investigated. The appropriate numerical models to fit the thermal conductivity of RE doped fluorides are proposed and discussed, which paves a theoretical foundation for subsequent similar research. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Experimental investigation of indirect solar dryer integrated with wicked heat pipe" published in the Journal of Mechanical Science & Technology. The correction addresses an error in the affiliation of the fourth author, stating that it should be corrected to "Hindusthan College of Technology and Science" instead of "Hindusthan College of Engineering and Technology." The article was authored by Vismaya K. Sachithanandhan, A. Asha Monicka, A. Brusly Solomon, G. Jeevarathinam, Tanmay Yadav, and Ajith R. The correction notice is published by The Korean Society of Mechanical Engineers and Springer-Verlag GmbH. [Extracted from the article]

Humidity plays a significant role in both daily life and industrial manufacturing. Adsorption-based dehumidification attracts considerable attention due to advantages of temperature and humidity independent control and great energy-saving potential. For adsorption-based dehumidification systems, desiccants are the basis for optimizing heat transfer and moisture adsorption performance. Despite the rapid advancements in materials science, few systematic classifications concerning composite materials are available. The primary objective of this paper is to provide a holistic and explicit roadmap of recent developments in composite desiccants, directing at its application in adsorption-based dehumidification for energy efficient utilization. Improvements in heat transfer can be achieved by adding high thermal conductivity materials or by reasonably designing structures of dehumidification components. Moisture adsorption is enhanced by combining different desiccants to maximize their functions. Three main categories are classified, that is, salt-embedded composites, porous matrix-polymer composites and polymer-polymer composites. This paper can help to identify the research gaps and explore promising approaches for future study to further enhance the energy efficiency of adsorption-based dehumidification technologies. [Display omitted] • A review of composites for adsorption-based dehumidification was completed. • High thermal conductivity additives and heat exchanger types can boost heat transfer. • Three main categories are classified for moisture adsorption improvement. • A comparative study was conducted on composites. [ABSTRACT FROM AUTHOR]

The article discusses the success and achievements of the journal Thermo in 2023. The journal was recognized for its quality and is now indexed in Scopus. The editorial process ensures the quality of each published paper, with an average decision time of 22 days. The journal saw an increase in visibility and full-text views, and a special issue was successfully completed. The article also highlights the key themes and advancements in thermal science covered by the journal, including thermodynamics, heat transfer, fluid mechanics, and alternative materials for sustainable energy. The readers are invited to contribute to the journal's success and the development of thermal science. [Extracted from the article]

• Pore-scale flow and conjugate heat transfer simulations in foams were performed using LBM accelerated by a GPU. • An anisotropic Kelvin foam was constructed based on the features of a real open-cell foam. • The anisotropic flow and heat transfer characteristics of foams were investigated. • The overall performance of real and Kelvin foams at a macroscopic level remains comparable even if they manifest differences at a microscale. Porous foam is a promising material in the field of science and engineering owing to its potential to offer heat transfer enhancement. In this work, an ideal Kelvin structure with considering anisotropy is constructed based on the characteristic parameters extracted from a real foam, and the flow and heat transfer characteristics in real and Kelvin foams is numerically investigated and compared by an in-house MRT-TLBM solver accelerated by a GPU. Results demonstrate that when the flow is along the elongation direction of the structure, the permeability is larger and Nusselt number is lower than those in the other directions for both real and Kelvin foams. Compared to the real foam, the Kelvin foam is more prone to inducing turbulence. For the overall performance of flow and heat transfer, the real foam behaves better at small Reynolds number (Re c <750), while Kelvin foam does when Re c exceeds 750 due to the different dominant mechanisms of heat transfer. In particular, the comprehensive factor (θ) of Kelvin foam is 12.8 % larger than that of the real foam at Re c =2000. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the problem of a compact furnace, to be used for in situ experiments in a cone-beam X-ray microtomography commercial system. The design process was accomplished and outlined through its main steps, until the realization of a prototype. The furnace was conceived to carry out wettability experiments at temperatures up to 700 °C and under inert atmosphere on sessile droplets of a molten metal alloy, with a few millimeters diameter, posed on a thin ceramic substrate. X-ray imaging of the molten droplet is expected to permit an accurate threedimensional reconstruction of the droplet profile and a robust estimation of the related quantities (such as the contact angle and the surface tension) utilized for the assessment of metal-ceramic joints by brazing. The challenges faced during this project, mostly related to the constraints of the setup, and the novel solutions implemented were discussed also with the support of analytical and numerical tools, in terms of interaction of X-rays with matter, geometry and working principle, heat transfer and insulation, material selection. [ABSTRACT FROM AUTHOR]

Ultrafast chip nanocalorimetry opens up remarkable possibilities in materials science by allowing samples to be cooled and heated at extremely high rates. Due to heat transfer limitations, controlled ultrafast cooling and heating can only be achieved for tiny samples in calorimeters with a micron-thick membrane. Even if ultrafast heating can be controlled under quasi-adiabatic conditions, ultrafast controlled cooling can be performed if the calorimetric cell is located in a heat-conducting gas. It was found that the maximum possible cooling rate increases as 1 / r 0 with decreasing radius r 0 of the hot zone of the membrane. The possibility of increasing the maximum cooling rate with decreasing r 0 was successfully implemented in many experiments. In this regard, it is interesting to answer the question: what is the maximum possible cooling rate in such experiments if r 0 tends to zero? Indeed, on submicron scales, the mean free path of gas molecules l m f p becomes comparable to r 0 , and the temperature jump that exists at the membrane/gas interface becomes significant. Considering the limitation associated with thermal resistance at the membrane/gas interface and considering the transfer of heat through the membrane, we show that the controlled cooling rate can reach billions of K/s, up to 1010 K/s. [ABSTRACT FROM AUTHOR]

• Unsteady rotating flow of nanofluid persuaded by Cattaneo–Christov diffusion is modeled. • Buongiorno model for nanoparticles is taken into account for modeling. • Variational finite element technique is implemented to solve the non-linear systems of partial differential equations. • Chemical reaction with novel aspect of activation energy is accounted. • Skin friction attains higher values for variable viscosity flow than that for constant viscosity flow. This article addressees the dynamics of fluid conveying tinny particles and Coriolis force effects on transient rotational flow toward a continuously stretching sheet. Tiny particles are considered due to their unusual characteristics like extraordinary thermal conductivity, which are significant in advanced nanotechnology, heat exchangers, material sciences, and electronics. The main objective of this comprehensive study is the enhancement of heat transportation. The governing equations in three dimensional form are transmuted in to dimensionless two-dimensional form with implementation of suitable scaling transformations. The variational finite element procedure is harnessed and coded in Matlab script to obtain numerical solution of the coupled non-linear partial differential problem. It is observed that higher inputs of the parameters for magnetic force and rotational fluid cause to slow the primary as well as secondary velocities, but the thermophoresis and Brownian motion raise the temperature. However, thermal relaxation parameter reduces the nanofluid temperature. The velocities for viscosity constant case are faster than that for the variable viscosity, but temperature and species concentration depict opposite behavior. [ABSTRACT FROM AUTHOR]

The present approach aims to describe the Soret and Dufour effects on the peristaltic flow of heat and mass transfer for two-dimensional tangent hyperbolic fluid model having cilia walls and electro-osmotic phenomenon in an asymmetric channel. To construct the governing equations, this model employs the long wavelength and low Reynolds number approach. The peristaltic phenomenon due to pressure with electro-osmotic flow have been developed. The flow also comprises of heat and mass rate and this phenomenon have been investigated along with viscous dissipation. The impacts of relevant variables on the velocity, temperature and concentration have been examined by using the graphical results in MATHEMATICA. Overall, the objectives of this work involve a comprehensive investigation of the complex interplay between various physical effects and fluid behavior within an asymmetric channel. This research aims to provide insights into the behavior of the system and its potential applications, especially in fields like microfluidics, biotechnology or materials science. [ABSTRACT FROM AUTHOR]

Thermoresistive probes are increasingly popular in thermal conductivity characterization using scanning thermal microscopy (SThM). A systematic analysis of the thermal conductivity measurement performance (sensitivity and spatial resolution) of thermoresistive SThM probe configurations that are available commercially is of interest to practitioners. In this work, the authors developed and validated 3D finite element models of noncontact SThM with self-heated thermoresistive probes under ambient conditions with the probe--sample heat transfer in transition heat conduction regime for the four types of SThM probe configurations resembling commercially available products: Wollaston wire (WW) type probe, Kelvin nanotechnology (KNT) type probe, doped silicon (DS) type probe and nanowire (NW) type probe. These models were then used to investigate the sensitivity and spatial resolution of the WW, KNT, DS and NW type probes for thermal conductivity measurements in noncontact mode in ambient conditions. The comparison of the SThM probes performance for measuring sample thermal conductivity and for the specific operating conditions investigated here show that the NW type probe has the best spatial resolution while the DS type probe has the best thermal conductivity measurement sensitivity in the range between 2 and 10W•m-1•K-1. The spatial resolution is negatively affected by large probe diameters or by the presence of the cantilever in close proximity to the sample surface which strongly affects the probe--sample heat transfer in ambient conditions. An example of probe geometry configuration optimization was illustrated for theWWprobe by investigating the effect of probe wire diameter on the thermal conductivity measurement sensitivity, showing ~20% improvement in spatial resolution at the diameter with maximum thermal conductivity measurement sensitivity. [ABSTRACT FROM AUTHOR]

The models and parameters related to the generated curing heat in the molding simulation of composite materials are dependent on the type of resin used and the experimental conditions. Therefore, in this study, we estimated the generated curing heat that changes with time by a data assimilation method, which combines the observation values with simulation values, so that the heat curing simulation of carbon fiber reinforced polymers (CFRPs) becomes closer to the experimental conditions. In the data assimilation method, the temperature distribution on the surface of the composite material was used as an observation value, and the generated curing heat was estimated using an ensemble Kalman filter. By optimizing the data assimilation parameters in advance using the response surface method and estimating the generated curing heat by numerical experiments, the generated curing heat could be estimated with an accuracy represented by the time mean error of less than 6%.

We describe a simple new miniaturized thermochemical module (MTM). Special considerations are needed to make the MTM useful not only for studying biomass conversion but also for providing safe classroom learning opportunities for heat and mass transfer and heterogeneous reaction engineering students and for training new researchers. The MTM consists of a quartz reactor wrapped with a Kanthal resistance wire and a silvered concentric annular glass shield for retaining thermal energy, placed in a protective Plexiglas viewing case. Safety is considered for use by new research trainees and within the classroom. We demonstrate MTM usage through five laboratory exercises beginning with an experimental design to determine operating modes to establish thermochemical conversion temperatures. Heat transfer skills are developed with the aid of a first-order differential heat transfer model and fractional factorial design. Thermochemical conversion is demonstrated and products are validated for pyrolysis, gasification, and combustion. The combustion laboratory also offers significant insight into reaction versus mass transfer-controlled regimes and for modeling heat transfer. Discussion is provided on the utility of the system for demonstrating heat transfer, kinetic, and mass transfer concepts, with applications across the engineering curriculum. [ABSTRACT FROM AUTHOR]

Gas-fired radiant panel arrays (RPAs) are a common experimental tool used in fire science and material testing. Unlike devices such as Cone Calorimeter or the Fire Propagation Apparatus (FPA), RPAs typically consume gaseous fuel within a porous medium through which fuel is burnt. When RPAs are used, thermal feedback from the surface of heated samples, as well as the effects of hot gases within the zone of convective influence of the RPA will cause an increase in the surface temperature of the RPA. To investigate this, experiments were conducted using a gas-fired RPA. Target samples made from vermiculite board, concrete, and a water-cooled aluminium plate were exposed to various severities of pre-calibrated incident radiant heat fluxes (HF). It was confirmed that the presence of a target sample led to an increased surface temperature for the RPA of nearly 80 °C (for a calibrated incident HF of 144 kW/m2). This increased surface temperature results in an incident HF nearly 78% higher than the pre-calibrated value at the sample's surface. Based on the results in this paper, a correction method has been proposed which can be used by gas-fired RPA users to account for the increase in incident heat fluxes. • Quantification of convective influence zone for gas-fired radiant panel arrays. • Quantification of thermal feedback effects on the presumed boundary conditions. • Suggestion of a correction method for thermal feedback effects. [ABSTRACT FROM AUTHOR]