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Activated carbon cold adsorbed H 2 storage (CAH2) is a promising physical hydrogen storage method. However, conventional storage tanks face problems of local high heat accumulation during the cold adsorption process, leading to low hydrogen storage efficiency and capacity. This study attempts to design high thermal conductivity fins to a conventional CAH2 tank to enhance heat and mass transfer, thereby promoting the hydrogen adsorption process. An accurate mathematical model and finite element method are established to calculate the CAH2 process. The influence mechanism of different fin arrangements, fin length, fin number (spacing), and fin width on the temperature field, adsorption concentration field and storage performance are explored. The results show that adding fins can effectively promote heat transfer and suppress local high temperature and low adsorption concentration areas. When the adsorption mass reaches 0.05 kg, the storage efficiency of the three tank schemes with added fins improves by approximately 40% compared with the original tank. Although extending the fin length will enhance heat conduction, it will also suppress the heat convective transfer effect. The optimal fin length is found to be 30 mm. Increasing the number of fins (reducing spacing) can significantly decrease the areas of local high temperature and low adsorption concentration, but this beneficial effect diminished when the number of fins exceeded 14. Increasing the fin width has a weaker beneficial effect on the temperature field and adsorption concentration field, and also cause a significant reduction in the tank volume, thereby reducing the total hydrogen storage capacity. The findings of this study can provide important guidance for the application of high thermal conductivity fins in CAH2 tanks. • The effect of adding fins on hydrogen adsorption process is explored. Dynamic temperature evolution. •The influence mechanism of different fin forms on heat transfer process is analyzed. •Most reasonable fin layout scheme and size parameters are obtained. •Adding fins can increase the hydrogen storage efficiency by more than 40%. [ABSTRACT FROM AUTHOR]

Inspired by natural bifurcated systems, a bionic microchannel system with tree-like topological structure is proposed, and applied for thermal management of proton exchange membrane fuel cell (PEMFC). The tree-like microchannel is optimized based on the minimization of flow resistance under steady laminar and pulsating flow conditions, respectively. Finite element simulations and microfluidic experiments are carried out for pulsating flow in the tree-like microchannel to determine its heat transfer performance. The results show that the optimized successive diameter ratio for the pulsating flow in a symmetric and dichotomous tree-like network is 0.707 (≈2−1/2), which is different from that of steady laminar flow (0.794≈2−1/3) known as Murray's law. Compared with steady flow, the application of sinusoidal-wave and rectangular-wave pulsating flow in a tree-like microchannel can further improve both the heat transfer efficiency and temperature uniformity. The tree-like microchannel with a length ratio of 2−2/3≈0.630 and diameter ratio of 2−1/3≈0.794 shows best performance under steady and pulsating flow modes. The present work has important theoretical significance for understanding the mechanism of natural bifurcated systems, and may provide theoretical basis and technical support for the industrial applications of bionic tree-like microchannel in thermal management of fuel cell and microelectronic device cooling etc. [Display omitted] • Bionic tree-like microchannel is designed for thermal management of PEMFC. • Optimized successive ratio of tree-like microchannel with pulsating flow is derived. • Thermal-hydraulic performance of bionic microchannel is investigated by FEM. • Mathematical model of bionic microchannel is validated by microfluidic experiment. [ABSTRACT FROM AUTHOR]

Additive manufacturing, particularly laser powder bed fusion (L-PBF), is an emerging method for fabricating complex parts in various industries. However, it faces the persistent challenge of thermal deformation, a significant barrier to its wider application and reliability. Current strategies, while partially effective, do not fully address the intricate thermal dynamics of the process, indicating a clear research gap in optimizing manufacturing techniques for better thermal management. This study focuses on understanding and mitigating thermal deformation in L-PBF using Genetic Algorithms (GAs). The application of GAs as a 'black-box' approach is explored to gain insights into the complex physics of L-PBF. A comprehensive investigation into the optimization of island sequencing within L-PBF processes is presented, employing GAs to systematically reduce thermal deformation. Various island sequences in a bilayered block structure are analyzed to assess the effectiveness of GAs in minimizing deformation, including scenarios such as variations in block sizes and interlayer rotation angles. Statistical tools such as silhouette scores and probability density distribution plots are utilized to provide a thorough analysis of deformation patterns and their respective thermal behaviors. The results show GA's remarkable efficiency in enhancing thermal management, achieving a significant reduction in thermal deformation within a range of 12–15% across the examined scenarios. This achievement highlights GA's capability in rapid optimization of scan sequences for better thermal deformation control. The findings enhance the understanding of thermal dynamics in L-PBF and consequently open new avenues for improving the quality and reliability of other metal additive manufacturing processes as well. [ABSTRACT FROM AUTHOR]

A thermal management method for data centers from the server level is proposed in this paper. This paper explores the high energy consumption of the server itself, proposing a principle of microchannel shape design for a cooling plate based on the principal stress lines (PSLs). Under the condition of a uniform load, the influence of the cross-sectional shape of the microchannel on the contact thermal resistance was found to be insignificant. From the analysis of cooling plate plane, the uniformity of the stress distribution of the microchannel determined the uniformity of the contact thermal resistance, which determined the heat dissipation ability. Experiments were developed to test and verify the cooling performance of the cooling plate as well as the performance differences with the microchannels along and away from the PSLs under deformation. It was concluded that compared with the conventional serpentine microchannel, the cooling performance of the cooling plate proposed in this paper was 4.5 $^\circ {\rm{C}}$ ∘ C reduction in average temperature. Furthermore, when the ultra-thin cooling plate was subjected to a uniform load distribution, the microchannel along a single PSL had the best stress distribution, that is, the contact thermal resistance had the least variation. [ABSTRACT FROM AUTHOR]

Solar evaporation attracted lots of attention due to its environment-friendly and high efficiency, which is a potential approach to collecting fresh water. Many efforts have been made to improve the evaporation rate in the open space. While the actual water collection rate is far less than the evaporation rate, especially in passive water collection, limiting its practical and scalable applications. In this review, we focus on freshwater collection based on solar evaporation. Firstly, heat and mass transfer behaviors on the evaporation side were summarized to improve evaporation performance, including heat transfer processes in thermal radiation, convection, and conduction; mass transfer processes in water supply, evaporation enthalpy, and salt rejection. Sequentially, subcooling, wettability, and geometry of the condensation side were discussed to improve water collection performance, which should be designed collaboratively with the evaporation side in a confined space. Finally, thermal recovery and electricity generation beyond water collection were also introduced, and some challenges still need to improve in the further for scalable and practical applications, including passive water collection rate, integrated system, and long-term issues. [ABSTRACT FROM AUTHOR]

Nanoporous graphene own high surface area and unique structural and physical properties due to nano-sized pores in graphene nanosheet. Nanoporous graphene has been modified by the introduction of surface functional groups, doping, or nanoparticle modification and applied for nanocomposites. The overview basically highlights design, properties, and potential of functionalized nanoporous graphene derived nanocomposites in advanced membranes (desalination/gas/oil separation), thermal management, electrocatalysts, and micro-supercapacitors. According to literature, pore size of neat nanoporous graphene is 3–11 Å and hydroxyl functional nanoporous graphene also had nanopore size of <10 Å. Functionalized nanoporous graphene revealed 100% salt rejection, while hydroxyl functional nanoporous graphene had 89% salt rejection due to altered surface properties. Both neat and functionalized nanoporous graphene has high gas permeance of ∼103–105 GPU towards separation CO2, CH4, N2, etc. Few attempts on micro-supercapacitor like molybdenum disulfide nanoporous graphene resulted in volumetric capacitance of 55 F cm−3 and capacitance retention of 82%. Forthcoming research on functionalized nanoporous graphene may overcome design/performance challenges leading to superior features and large-scale utilizations. [ABSTRACT FROM AUTHOR]

High‐power electronics require thin, conformal insulation that resists dielectric breakdown, while promoting removal of heat from the device. Recently, polyelectrolytes have shown promise in creating dielectric thin films, but their thermal conductivity remains relatively low (<1 W m−1 K−1). In this work, the layer‐by‐layer (LbL) assembly of polyethylenimine, mica clay, poly(acrylic acid), and hexagonal boron nitride is exploited to create a thin film dielectric material with relatively high thermal conductivity (through‐plane thermal conductivity of 1.87 ± 0.03 W m−1 K−1) and strong electrical insulation (breakdown strength of 152 kV mm−1). High thermal conductivity is obtained due to mica and hexagonal boron nitride nanoplatelets stretching through multiple layers. The performance benefits of this nanocomposite are demonstrated with a partial motor, where the nanocomposite greatly reduces the peak temperature of the motor when compared to state‐of‐the‐art polyimide insulation. This remarkable combination of thermal conductivity and dielectric breakdown strength represents a significant advancement in the electrical and thermal protection of high voltage devices. [ABSTRACT FROM AUTHOR]

Thermal management is crucial in advanced wearable electronics, especially those with high integration and miniaturization, or incorporating self‐powered systems utilizing body heat. However, the low thermal conductivity of traditional silicone rubber encapsulation presents a major challenge to thermal management in wearable electronics. In this study, hexagonal boron nitride@Eutectic Gallium‐Indium/Ecoflex (h‐BN@EGaIn/Ecoflex) composites, a soft elastic material is developed that is thermally conductive yet electrically insulating, capable of serving as encapsulation and thermal interface materials in wearable devices. The key of successfully designing h‐BN@EGaIn/Ecoflex composites with such thermal, mechanical, and electrical properties is the anchoring of EGaIn on the h‐BN surface. Also, there exists a trade‐off in thermal‐electrical and thermal‐mechanical properties of the composites during the preparation of h‐BN@EGaIn hybrid fillers and their incorporation into the Ecoflex elastomer. In application demonstrations, through replacing the polydimethylsiloxane supporting layer with h‐BN@EGaIn/Ecoflex composites, a 20 K operation temperature decrease is observed in a wearable light‐emitting diode lamp. In addition, the output of a wearable thermoelectric generator encapsulated with h‐BN@EGaIn/Ecoflex composites increases by 100% compared to that encapsulated by Ecoflex. These results clearly show the benefits of substituting h‐BN@EGaIn/Ecoflex for silicon rubber encapsulation in wearable electronics. [ABSTRACT FROM AUTHOR]

Given the critical threats to aviation safety induced by electromagnetic interference (EMI), fire hazards, and icing, high‐performance multifunctional materials integrating mechanical flexibility, EMI shielding, fire resistance, and thermal management capabilities are highly desired yet challenging. Herein, a synergistic strategy is developed involving defect engineering and graphitization to enhance EMI shielding and thermal management properties of SiBCNZr nanofiber fabrics. Initially, the SiBCNZr nanofiber fabrics demonstrate excellent mechanical flexibility and intrinsic ceramic fire resistance. Furthermore, after annealing at 1400 °C, t‐ZrO2 nanograins with various types of defects are precipitated from the amorphous matrix, accompanied by the formation of turbostratic graphite C. The synergistic effects of defect engineering of t‐ZrO2 nanograins and graphitization of turbostratic C enhance conductivity and polarization loss, leading to a specific shielding effectiveness (SSE/t) of 2718 dB cm2 g−1. Additionally, the fabrics also demonstrate remarkable electrothermal conversion capability with a rapid electrothermal response. This work provides valuable insights into designing multifunctional EMI shielding ceramic nanofiber fabrics for aviation safety. [ABSTRACT FROM AUTHOR]

Electric vehicles, as a major strategy for climate change mitigation, uses lithium-ion batteries extensively as the power source. However, the operation, performance and lifetime of lithium-ion batteries depend on the battery temperature, which can have a wide range due to heat generation within the battery and significant variations in the ambient conditions due to changes in seasons and geographical locations where electric vehicles are operated. In the present study, thermal management methods/strategies on the capacity fade of lithium-ion batteries are assessed through a validated capacity fade model for lithium-ion batteries along with a thermal model for the heat generation in the battery and dissipation over battery surface, represented by various thermal management methods. The driving conditions are simulated through a constant and various standard drive cycles. It is shown that battery temperature has the predominant impact on the capacity fade, and it can be controlled through effective thermal management. A much more significant spread in battery capacity fade occurs with various thermal management methods for a lower initial battery temperature (20°C) compared to the higher temperatures (35°C and 50°C), hence, thermal management is much more effective in reducing capacity fade at battery temperatures close to 20°C, which is considered the optimum operating temperature for lithium-ion batteries. Further, the results indicate that using a lower charge voltage can result in slightly less capacity fade over cycling. Regenerative braking makes it more realistic to use lower charge voltages, since the battery can be recharged during operation, thereby increasing driving range, while preventing increased capacity fade. Effective thermal management is more imperative for realistic intense and aggressive driving behaviors. [ABSTRACT FROM AUTHOR]

Commercial thermally conductive dielectric materials used in electronic packaging typically exhibit thermal conductivities (κ) ranging from 0.8 to 4.2 W m−1 K−1. Hexagonal boron nitride (h‐BN) flakes are promising thermally conductive materials for the thermal management of next‐generation electronics. These electrically insulating yet thermally conducting h‐BN flakes can be incorporated as thermal fillers to impart high κ to polymer‐based composites. A cellulose‐based composite embedded with few‐layer h‐BN (FLh‐BN) flakes, achieving a κ ≈ 21.7 W m−1 K−1, prepared using a cost‐effective and scalable procedure is demonstrated. This value is >5 times higher than the κ observed in composites embedded with bulk h‐BN (Bh‐BN, κ ≈ 4.5 W m−1 K−1), indicating the benefits of the superior κ of FLh‐BN on the κ of h‐BN polymer composites. When applied as a paste for thermal interface material (TIM), the FLh‐BN composite can reduce the maximum temperature (Tmax) by 24.5 °C of a heating pad at a power density (h) of 2.48 W cm−2 compared to Bh‐BN composites at the same h‐BN loading. The results provide an effective approach to improve the κ of cellulose‐based thermal pastes for TIMs and demonstrate their viability for heat dissipation in integrated circuits (ICs) and high‐power electronic devices. [ABSTRACT FROM AUTHOR]

The unique structure of penguin feathers endows them with extremely high thermal insulation properties in extreme cold environments via sunlight absorption, heat insulation and infrared reflection. Herein, inspired by a thermal insulation strategy of the penguin feathers, the laminated wearable textile with coupled thermal insulation was fabricated for thermal management. The outermost layer, comprised of carbon nanotube-cellulose, simulates the black tip of the penguin's dorsal feather, exhibiting exceptional light-to-heat conversion as it can swiftly elevate its temperature by 5 ℃ upon exposure to simulated sunlight. The middle layer, constructed from polylactic acid, mimics the intermediate section of the penguin's feather, achieving effective heat insulation by trapping significant amounts of air. And the innermost layer MnO2-cellulose membrane is functionally similar to the fluff of the penguin closest to the skin, reflecting the infrared radiation of the body to reduce heat loss. Additionally, the textile underwent hydrophobic modification, endowing it with waterproof properties, resulting in an alteration of the exterior contact angle from 52.2 to 118.8°. Furthermore, the textile displayed anti-ultraviolet capabilities (with ultraviolet transmittance below 8%), excellent mechanical performance (with tensile strength is 3.22 MPa) and active deicing properties, enhancing the wearable comfort. This work represents a versatile and comprehensive textile learning from the bionic structure of penguin feathers for highly efficient thermal management applications, making it attractive for textiles to satisfy various wearable applications in cold environments and even extreme weather conditions. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) offers significant advantages over fusion welding, particularly for high-strength alloys like Inconel 718. However, achieving optimal surface quality in Inconel 718 FSW remains challenging due to its sensitivity to temperature fluctuations during welding. This study integrates finite element simulations, statistical analysis, and advanced control methodologies to enhance weld surface quality through adequate thermal management. High-fidelity simulations of the FSW process were conducted using a validated 3D transient COMSOL Multiphysics model, producing a comprehensive dataset correlating process parameters (rotational speed, axial force, and welding speed) with workpiece temperature. This dataset facilitated statistical analysis and parameter optimization through Analysis of variance (ANOVA) method, leading to a deeper understanding of process variables. A nonlinear state-space system model was subsequently developed using experimental data and the system identification toolbox in Matlab, incorporating domain-specific insights. This model was rigorously validated with an independent dataset to ensure predictive accuracy. Utilizing the validated model, tailored control strategies, including proportional-integral-derivative (PID) and model predictive control (MPC) in both single and multivariable configurations, were designed and evaluated. These control strategies excelled in maintaining welding temperatures within optimal ranges, demonstrating robustness in response times and disturbance handling. This precision in thermal management is poised to significantly refine the FSW process, enhancing both surface integrity and microstructural uniformity. The strategic implementation of these controls is anticipated to substantially improve the quality and consistency of welding outcomes. [ABSTRACT FROM AUTHOR]

Aircraft electrification introduces challenges in power and thermal management. In a hybrid-electric aircraft (HEA), the additional heat loads generated by the high-power electrical components in the propulsion system can negate the benefits of the HEA. Consequently, an integrated energy management system is required for the HEA to reject the additional heat loads while minimizing energy consumption. This paper presents the integrated modeling method for an integrated power and thermal management system (IPTMS) for HEA. With this method, a platform can be developed to assess the varying efficiencies of the components in the electrical propulsion system (EPS), such as the battery, motor, bus, and converter, and the performance of the thermal management system (TMS), such as passive cooling, during a flight mission. This makes it applicable to modular designs and optimizations of the IPTMS. A small/medium range (SMR) aircraft similar to ATR72 is studied to demonstrate the platform's capabilities. In this study, the EPS operates only during takeoff and climb. It provides supplementary propulsive power, which declines linearly from 924 kW to zero. Therefore, the platform assesses the heat and power loads of the IPTMS for a typical flight mission (takeoff and climb) in this study. The performance of passive cooling is also analyzed across this typical flight mission and under normal, hot-day, and cold-day conditions. It was found that under the normal condition, after the midclimb flight mission, the EPS components except for the motor and the inverter can be cooled sufficiently by the passive cooling mechanism without any need for active cooling. However, the battery temperature decreases below its minimum operating temperature (15 °C) after the late-climb segment indicating the need for active temperature control to prevent damage. The passive cooling is still sufficient under the hot-day and cold-day conditions. Additionally, compared with the normal condition, the points at which passive cooling is sufficient to cool the component move forward in the hot-day condition and backward in the cold-day condition, respectively. Under the hot-day condition, the battery temperature is below its minimum temperature after the late-climb, still requiring active temperature control. In the cold-day condition, the bus, the converter, and the battery require active temperature control to prevent their temperatures below the minimum temperatures. Additionally, the heat from the gas turbine (GT) engine has a positive impact to ensure the motor and the inverter operate at their operating temperatures in cold conditions. The studied aircraft can be assessed with the integrated model under normal, hot-day, and cold-day conditions for heat and power loads, as well as passive TMS performance. This demonstrates the adaptability of the integrated modeling method. These findings imply the potential to minimize TMS weight and energy consumption, providing an insight for further research on IPTMS. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive numerical investigation into the thermal performance of solar collectors integrated with encapsulated phase change materials (PCMs) using a transient three-dimensional (3D) approach. The performance of two distinct PCMs—paraffin wax and RT60—was evaluated under varying operational conditions, including seasonal variations, inlet pipe velocities, and inlet temperatures. The results indicate that paraffin wax exhibits a higher peak temperature, reaching approximately 360 K, compared to RT60's peak of 345 K, making paraffin wax more effective for consistent thermal energy storage. Paraffin wax also maintained higher fluid fractions, with a maximum of 0.9 in summer, indicating superior heat absorption and retention capabilities. In contrast, RT60 demonstrated a quicker phase transition, fully liquefying at a lower fluid fraction, which is advantageous for rapid heat release. Seasonal variations significantly impacted system efficiency, with the highest efficiency observed in June at 365 K and the lowest in December at 340 K. The study also found that lower inlet velocities (e.g., 0.25 L/s) significantly improved heat retention, resulting in higher outlet temperatures, while increasing the inlet temperature from 290 K to 310 K led to a marked increase in outlet temperatures throughout the day. These findings underscore the importance of optimizing PCM selection, inlet velocity, and temperature in enhancing the performance of solar thermal systems, offering quantitative insights that contribute to the development of more efficient and reliable renewable energy solutions. [ABSTRACT FROM AUTHOR]

The continued depreciation of electronic components presents severe challenges for thermal management. Regarding this issue, the current experimental study targets to propose and assess two passive cooling (using a heat sink and rough surface) and two active cooling (air and water cooling) for improving the cooling efficiency of aluminum heat sink heat pipes (HSHPs). In roughening process, the fins are chemically etched using a lab-made simple, cost-efficient, and environmental-friendly method to achieve better cooling performance synergistically. Scanning electron microscopy and atomic force microscopy characterizations are executed to investigate the heat sink surfaces' micro/nano roughened structure. Current results and related comparative studies of the three cooling modules (typical, liquid-based, and liquid-based micro/nano roughened HSHPs) are presented as well, where effects of constant/intermittent heat fluxes (4000–12000 W/m2) and the volume flow rates of testing fluid on heat transfer characteristics, thermal resistance, and temperature behavior are disclosed. Based on findings, at a constant heat flux, roughening the HSHP fins led to an enhancement in cooling through fins and a reduction in cooling through the water. Moreover, it is found that the modified HSHP without testing fluid and with water at volume flow rates of 100 and 200 ml/min decreases the thermal resistance by 11.9, 13.7, and 3.6%, in order, compared with the typical HSHP. [ABSTRACT FROM AUTHOR]

The market share of blade batteries is rising rapidly due to their high energy density, efficient space utilization, and low cost. Nevertheless, effective cooling solutions for blade batteries are crucial to ensure the safe operation of electric vehicles, especially in extreme high-temperature environments. This paper numerically investigates the effects of a cooling plate and the blade battery parameters on maximum battery temperature, maximum temperature difference, and cooling water pressure drop. Additionally, the energy efficiency of these solutions under various cooling demands is analyzed. The numerical results show that increasing the channel number and changing the flow direction does not significantly improve the cooling performance of the cooling plate. Moreover, the effect of cooling water temperature on the maximum temperature difference in blade batteries is negligible. Furthermore, increasing the cooling water mass flow rate and the rotational speed of the cooling fan is preferred when Tmax − Ta > 6 K, while reducing the cooling water temperature is more energy-efficient when Tmax − Ta < 6 K. These results are expected to offer theoretical guidance and data support for designing cooling systems for blade batteries in extreme high-temperature environments. [ABSTRACT FROM AUTHOR]

In contemporary vehicle applications, lithium-ion batteries have become a leading option among the diverse array of battery technologies available. This preference is attributed to their advantageous properties, which include low self-discharge rates and no memory effect. Despite these benefits, lithium-ion batteries are not without their challenges. The key issues include a restricted driving range, concerns regarding longevity, safety risks, and prolonged charging durations. Efforts aimed at minimizing the charging duration frequently entail the introduction of elevated currents into the battery, a practice that can significantly elevate its temperature and, in turn, diminish its operational lifespan. Generally, battery packs in electric vehicles are equipped with flat cooling plates located on their side or bottom surfaces, which also serve the dual purpose of providing heating in colder conditions. Nevertheless, this cooling configuration faces difficulties during fast charging and may not efficiently heat or cool the batteries. In this work, a novel thermal management approach is proposed, in which a battery module is cooled not only with a bottom cooling plate but also using another cooling plate in contact with the busbars, located on the top of the battery module. The simulations and experimental tests show that this new configuration demonstrates significant improvements. The thermal time constant is reduced by 47%, enabling faster cooling of the module. Additionally, the maximum temperature reached by the battery during charging with dual cooling is lowered by 6 °C compared to the conventional approach. In this configuration, the top cooling plate acts as a thermal bridge. This is a key advantage that promotes temperature homogenization within the battery module. As a result, it supports an even aging process of batteries, ensuring their longevity and optimal performance. [ABSTRACT FROM AUTHOR]

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Energy efficiency is critical for achieving building sustainability because it means that fewer resources are consumed. In this context, the advancement of phase-changing materials has attracted attention with regard to the integration and management of energy efficiency in construction projects. Buildings consume 40% of the global energy output annually, accounting for one-third of the global greenhouse gas emissions. For hot weather-prone construction, PCMs should have a melting temperature of 25–50 °C. For more than 30 years, researchers worldwide have experimented with PCMs at various temperatures, but few studies have been conducted in hot or harsh environments. According to recent studies, the amount of PCMs in construction materials has been limited to 20%, and exceeding this ratio was shown to significantly affect the compressive strength of concrete specimens. In this study, various phase-changing concrete materials were investigated to reduce the thermal energy consumption of buildings. This paper aims to provide an overview of the current state-of-the-art phase change materials for constructing thermal energy storage building materials. It also includes a brief review of the most recent developments in phase change technologies and their encapsulation techniques based on thermophysical properties. Implementing PCM technology in buildings will also maintain good indoor air quality. These materials are widely used in various real-time applications to significantly enhance thermal comfort in buildings. [ABSTRACT FROM AUTHOR]

Textiles, serving as a second skin for the human body, play a significant role in regulating the microenvironment temperature, and enhancing thermal comfort of the human body during cold weather. However, the most current methods for enhancing the warmth of fabrics involve complex chemical treatment or the application of advanced materials, thus suffering from potential chemical toxicity (especially for infants), complex processing and high cost. Herein, we report a simple strategy for directly processing cotton roving into environmentally friendly and structurally stable thermal-retention cotton textiles by means of hierarchically self-locking structures. The textile not only shows excellent heat-retention properties and mechanical firmness compared with conventional thermal insulation wadding and certain commercial blankets, but is also environmentally friendly and cost effective. This method may provide a new generation of thermal insulation materials with enhanced health and environmental benefits based on hierarchical structure design and natural textile materials. [ABSTRACT FROM AUTHOR]

Epoxy resin, characterized by prominent mechanical and electric‐insulation properties, is the preferred material for packaging power electronic devices. Unfortunately, the efficient recycling and reuse of epoxy materials with thermally cross‐linked molecular structures has become a daunting challenge. Here, we propose an economical and operable recycling strategy to regenerate waste epoxy resin into a high‐performance material. Different particle size of waste epoxy micro‐spheres (100–600 μm) with core‐shell structure is obtained through simple mechanical crushing and boron nitride surface treatment. By using smattering epoxy monomer as an adhesive, an eco‐friendly composite material with a "brick‐wall structure" can be formed. The continuous boron nitride pathway with efficient thermal conductivity endows eco‐friendly composite materials with a preeminent thermal conductivity of 3.71 W m−1 K−1 at a low content of 8.5 vol% h‐BN, superior to pure epoxy resin (0.21 W m−1 K−1). The composite, after secondary recycling and reuse, still maintains a thermal conductivity of 2.12 W m−1 K−1 and has mechanical and insulation properties comparable to the new epoxy resin (energy storage modulus of 2326.3 MPa and breakdown strength of 40.18 kV mm−1). This strategy expands the sustainable application prospects of thermosetting polymers, offering extremely high economic and environmental value. [ABSTRACT FROM AUTHOR]

The thermally anisotropic building envelope (TABE) is an active building envelope that redistributes thermal loads in response to weather conditions and building energy demand. Conductive layers throughout the TABE distribute low-grade heat among hydronic loops, altering heat flow direction and intensity. Finite element models of TABE roof and wall panels were developed and calibrated using field evaluation data. The calibration results showed that heat flux differences between the experimental data and finite element models averaged −0.42% and 3.57%, with a maximum mean square error of 1.78 and 3.96 for roof and wall panels, respectively. A reduction in heat flux from the environment to the building living space over the entire testing period (weeks in July/August) was found to be 85% for roof panels and 335% (load reversed) for wall panels. These results indicate TABE can effectively harness low-grade thermal energy sources to achieve high energy efficiency and promote demand-side management. [ABSTRACT FROM AUTHOR]

Smart clothing with adaptive personal thermal management functionality is highly desirable for wearing comfort and energy efficiency. However, due to the lack of common materials that can fabricate dynamic thermoregulation fabrics, translating the existing technologies to commercial applications remains challenging. Herein, leveraging an industrial textile manufacturing approach, a hierarchically programmed meta‐louver fabric with switchable modes for both hot and cold is developed. The efficacy of adaptive pore channels by manipulating the orientation of chiral knit loops to regulate water evaporation, as well as thermal convection and radiation, is experimentally demonstrated. In sharp contrast to current pore‐actuated smart textiles, the designed meta‐louver fabric gains its adaptive thermoregulation capacity directly from the multiscale textile structure engineering, ranging from the single‐helical‐fiber enabled yarn actuators to pre‐tension induced chiral‐helical knit loops. This strategy is shown to be also effective for other fiber materials, such as cotton, and thus provides a universal paradigm for a new family of metamaterials by engineering the interconnection of multiscale structures. [ABSTRACT FROM AUTHOR]

Metal hydrides provide a safe and efficient way to store hydrogen. However, current metal hydride storage systems, i.e., hydrides incorporated within a storage tank, are far from efficient. Depending on the design, (dis)charging rates may be very long. However, this can be significantly improved by implementing strategies tackling the issue of heat management at the level of: i) the metal hydride bed, and ii) the overall storage system design. This review summarises recent progress in tackling heat management of hydride systems. In this respect, modeling has emerged as a powerful tool. In particular, simulation results show that the compaction of hydride powders with binders and the use of metal foams are both effective in lifting the poor thermal conductivity of hydride beds. For tank designs, cylindrical shapes remain the preferred choice because of the flexibility and ease of supplementing heat management with fins and tubular heat exchangers. The addition of phase change materials to the hydride tank can lead to further heat storage, but any add‐on to simple hydride tanks can only lead to cumbersome systems. It is still a fine art to tune the thermal conductivity of hydride beds while selecting a suitable metal hydride alloy composition. [ABSTRACT FROM AUTHOR]

Passive thermal energy storage systems using phase change materials (PCMs) are promising for resolving temporal‐spatial overheating issues from small‐ to large‐scale platforms, yet their poor shape stability due to solid–liquid transition incurs PCM leakage and weak resistance against mechanical disturbance, limiting practical applications. While foam‐stable templates for PCMs have shown complement, they reveal massive leakage and collapse of liquefied PCMs under external loads or impacts. Herein, a multiscale porous architecture consisting of graphene aerogels (GAs) and meta structures enabling robust thermal‐mechanical functionalities of PCMs (3D‐MPGA) toward sustainable phase change thermal energy storage composites is reported. 3D‐printed mechanical metamaterials employing octet‐truss cells provide supportive strength and directionally‐assisted leakage reduction, while GAs serve as porous templates with surface‐interfacial contacts, thereby fixing paraffin wax as PCM inside their nano/micropores. The 3D‐MPGA shows intrinsic thermal characteristics of bulk PCMs, and improved thermal‐mechanical‐chemical stability, confirmed by long‐term heating‐cooling cycle tests over 10 h. Moreover, it exhibits highly reinforced strength (200–5000%) within a low density across ambient and melting temperatures, and maintains original shapes in the liquefied PCMs without severe leakage, against external loads. This work inspires rational strategies for advancing robust thermal‐mechanical functionalities for PCM‐based thermal energy storage systems. [ABSTRACT FROM AUTHOR]

Industrialization and human activities have introduced numerous hazards, including exposure to harsh chemicals, radiation, static electricity, and fire risks, particularly in high‐risk sectors such as engineering, rescue operations, military, and aerospace. This study presents a multi‐functional protective textile developed from a conductive fiber composed of polytetrafluoroethylene (PTFE) and carbon nanotubes (CNT), crucial for ensuring personal safety. The conductive fiber demonstrates remarkable strength (17.3 MPa), high porosity (76%), and significant electrical conductivity (185 S m−1), coupled with excellent fineness and flexibility due to its dual‐nanofibrous structure. The resulting textile exhibits exceptional hydrophobicity, chemical resistance, and high electromagnetic interference shielding effectiveness (29 dB in the X‐band), alongside a superior UV protective factor (>3000) and anti‐static properties. Notably, it possesses outstanding electro/photo thermal conversion capabilities, enabling consistent heat generation for personal warmth. Additionally, the textile responds electrically to deformation and temperature changes, facilitating intelligent applications such as motion and temperature monitoring and fire alerts. This work offers a novel strategy for fabricating PTFE‐based composite fibers with porous microstructures and high electrical conductivity, setting a new standard for next‐generation protective clothing with advanced functionalities. [ABSTRACT FROM AUTHOR]

Highlights Despite the continuous development and improvement of many technologies and multifunctional materials for the electric powertrain (ePowertrain) for electric vehicles, there are still technical issues and challenges to address such as thermal management in batteries, electric motors, and power electronic devices, as most of their failures are due to poor thermal management. Consequently, conventional engineering polymer materials already used must be replaced since most of them have low thermal conductivity and are therefore limited in performance for thermal management applications. A key solution is to develop highly thermally conductive polymer composites that combine other features, such as flame‐retardant, electrical insulation, and mechanical and barrier properties, by incorporating fillers into the polymer matrix. This approach has attracted intensive research efforts. In this review, we first examine the key drivers, trends, and solutions of the ePowertrain segment, emphasizing thermal management. Second, special attention is given to the state‐of‐the‐art boron nitride (BN) polymer composites with current or potential applications in the automotive industry, especially, in batteries, electric motors, and power electronics. Third, analysis and prediction of thermal properties of BN polymer composites by finite element simulation are presented. Finally, outlooks for future research in this field are highlighted. Thermal management of batteries, electric motors and power electronics, using BN polymer composites, optimizes the functionality of electric vehicles. Cross‐linked polymers with BNNSs provide resins for high power motors, film capacitors, and Li‐metal battery electrolytes for electric vehicles. Mathematical modeling and life cycle analysis can predict trends and research gaps in ePowertrain applications. [ABSTRACT FROM AUTHOR]

In the rapidly advancing field of 5G technology, efficient thermal management is essential for enhancing the performance and reliability of high-power-density integrated circuits (ICs). This paper introduces an innovative approach to cooling these critical components, significantly surpassing traditional methods. Our design optimizes heatsink and fan configurations through systematic experimentation, varying fin shapes, heatsink dimensions, and fan speeds. The results demonstrate that fan velocity is the most critical factor in reducing IC temperatures, as increased airflow dramatically lowers thermal output. Expanding the heatsink surface area further improves heat dissipation by enhancing airflow interaction, while a larger copper heatsink boosts thermal conduction, effectively reducing the final IC temperature. These optimizations streamline the cooling process, minimizing the need for more complex and expensive equipment. This research sets a new benchmark in thermal management, fostering the development of more efficient and reliable electronic systems in the era of advanced wireless communications. Our approach brings a new dimension to existing research by focusing on the optimization of heatsink and airflow designs specifically for ICs. While previous studies have explored broader thermal management strategies, our work addresses specific challenges in heat dissipation by refining geometric configurations and fan speed adjustments. These optimizations result in measurable improvements in both efficiency and scalability, particularly within the context of high-power 5G systems. [ABSTRACT FROM AUTHOR]

Maintaining body temperature within safe and comfortable range is crucial; however, thermoregulatory materials face challenges in variable environments and extreme application scenarios. Here, a unique dual air‐gelation strategy is developed to synthesize carbon aerogel nanofiber metafabric for energy‐harvesting thermoregulation. By manipulating polyacrylonitrile/water interaction and charge density of the solution, phase separation and Coulombic repulsion in electrospun jets are promoted, forming curly nanofibers with internal nanopores (size 30–60 nm) that entangle to create nanofibrous dual‐aerogel structure; the carbon aerogel nanofiber metafabric is obtained following pre‐oxidation and optimized graphitization. The resulting metafabric exhibits high elasticity, robust temperature resistance from −196 to 600 °C, exceptional thermal insulation performance, high‐efficiency electrothermal capability (adjustable from 15 to 150 °C), and photothermal property (radiation raised temperature by 22 °C). This work provides rich possibilities to develop advanced carbon nanomaterials for thermal management. [ABSTRACT FROM AUTHOR]

In recent years, hexagonal boron nitride (h‐BN) has gained attention for its potential applications in thermal management and high‐temperature uses. To evaluate the environmental impact of employing h‐BN nanocomposites in microelectronics packaging for thermal management, a comprehensive assessment was conducted. This assessment is particularly significant due to the nature of nanoparticles and the importance of mitigating potential environmental toxicity. Electronic waste incineration, compared to e‐waste recycling, carries a higher environmental burden. Building on previous research, this project explores the feasibility of h‐BN nanocomposites in microelectronic packaging for thermal management. The study focuses on the physiochemical transformations of h‐BN nanocomposite underfills during incineration, considering the influence of particle size and concentration on these transformations. Various analytical techniques, including SEM, XRD, FTIR spectroscopy, and TEM, were employed to identify and characterize the particles throughout their life cycle. By delving into physiochemical transformations and investigating the effects of particle size and concentration, this research enhances our understanding of h‐BN nanocomposites, aiding informed decision‐making for environmentally sustainable use in microelectronics packaging. Highlights: h‐BN nanoparticles remained inert throughout their life cycle.Underfill characterization showed minimal physiochemical changes in h‐BN.h‐BN is a promising thermal transfer candidate in microelectronics. [ABSTRACT FROM AUTHOR]

Energy‐efficient building materials are eye‐catching for reducing indoor energy consumption via eliminating electromagnetic interference and pollution, controlling the thermal transfer, and promoting sunlight harvesting and providing a comfortable living environment. To realize broadband microwave shielding, the elaborate control of microstructures has showed great potential and research direction. By composition regulation and structure design with various dimension, the synergistic effects including conductive networks, interfacial polarization, magnetic coupling, dipole polarization, and dielectric‐magnetic synergy, can significantly improve electromagnetic (EM) shielding capacity. Thermal management including thermal conversion, thermal storage, thermal radiation, and thermal conduction has enormous potential in enhancing the sustainability and energy efficiency for future buildings. Smart windows are able to switch optical transmittance and colors, which is contributed to saving building energy. Herein, in this review, the recent progress of broadband shielding, thermal management, and smart window in the field of energy‐efficient buildings is summarized, from the aspects of materials, mechanisms, and scenarios. Further, the main bottlenecks and problems are discussed, and potential research opportunities are further highlighted. [ABSTRACT FROM AUTHOR]

This study numerically analyzed different substrate board materials, including FR4, silicon, and copper, for electronic component cooling. Ten diverse components were mounted on these boards and subjected to uneven heat distribution. Both natural and forced air cooling were tested at various speeds. Copper cladding significantly lowered component temperatures by 34-54 degrees Celsius compared to FR4 or silicon at 7 m/s. Moreover, copper allowed for lower fan speeds (5 m/s) while keeping component temperatures below 100 degrees Celsius, reducing energy consumption. These results offer valuable guidance for thermal engineers in selecting optimal substrate boards for efficient electronic cooling. [ABSTRACT FROM AUTHOR]

The performance of solar photovoltaic (PV) panels is significantly affected by their operating temperature, with higher temperatures leading to decreased efficiency and reduced lifespan. This study explores the enhancement of PV panel performance through the implementation of an advanced cooling technology that combines Phase Change Materials (PCM) with forced convection. The PCM layer, strategically placed at the back of the PV panel, absorbs and stores thermal energy during periods of high solar irradiance, while the forced convection system actively dissipates excess heat. A comprehensive simulation of this hybrid cooling system is conducted using ANSYS software. The simulation involves creating a detailed 3D model of the PV panel, assigning appropriate material properties, and setting up transient thermal analysis to capture the dynamic thermal behavior throughout a typical day. The results indicate that the integration of PCM and forced convection significantly reduces peak temperatures of the PV panels, thereby enhancing their efficiency and potentially increasing their operational lifespan. This innovative cooling solution presents a promising avenue for improving the performance and reliability of solar PV systems. The ANSYS simulation results reveal that the combined PCM and forced convection cooling system effectively reduces the peak temperatures of the solar panels. This temperature reduction significantly improves the electrical efficiency of the panels and suggests the potential for extending their operational life. The study confirms the feasibility of this hybrid cooling method as a practical and effective solution to enhance the performance and reliability of solar panel installations, paving the way for more sustainable and efficient solar energy systems. [ABSTRACT FROM AUTHOR]

Thermal management is essential for maintaining optimal performance across various applications, including personal comfort, electronic systems and industrial processes. Thermal-management fibers and textiles have emerged as innovative solutions to manipulate heat transport, storage and conversion efficiently. This review explores recent advancements in material innovations in this field. We summarize the novel fibers and textiles designed for controlling heat transport through different pathways, progress in developing phase-change-material-based fibers and textiles for heat storage regulation, and application of photothermal conversion, Joule heating and thermoelectric effect as energy conversion routes in advanced fibers and textiles. Furthermore, we discuss the challenges and future perspectives of this field. It is believed that ongoing research and development promise to bring about innovative thermal-management solutions catering to demands across multiple sectors. [ABSTRACT FROM AUTHOR]

To achieve effective temperature-regulated modification of spray-bonded cotton for superior thermal management capabilities, a dual-network phase transition microspheres (PCP) was developed through a one-step process using emulsion polymerization. This innovative approach incorporated eutectic polyethylene glycol (PEG) as the phase change component, chemically cross-linked polyacrylamide (PAM) as the first network, and ionically cross-linked calcium alginate (CA) as the second network. The PCP, which contains PEG solid-loaded in the dual network, was utilized as a modifier for the post-treatment of spray-bonded cotton using a coating technique. Key findings reveal that the effectively immobilization of PEG has been, without any abserved chemical reactions between PEG and PAM/CA. Additionally, PEG maintained its crystalline properties when combined with PAM/CA. The PCP exhibited a distinct morphology with smooth, spherical particles averaging round 5 μm in diameter. The optimized PCP sample exhibits a melting onset temperature of 37.20 °C, a melting enthalpy of 92.59 J·g−1, and impressive heat resistance. The resulting temperature-regulated spray-bonded cotton (TRSBC) displayed intelligent temperature control characteristics with a melting onset at 37.65 °C and a latent heat of 32.08 J·g−1. Compared to untreated spray-bonded cotton (USBC), TRSBC exhibited a notable delay effect in both heating and cooling processes, resulting in a temperature differential of 23.5 °C during heating and 16.3 °C during cooling, underscoring its superior temperature control capabilities. Research indicates that TRSBC possesses significant potential in thermal management applications, encompassing clothing, high-tech textiles, and temperature-regulating sandwich panels, thereby presenting considerable opportunities for commercial ventures. [ABSTRACT FROM AUTHOR]

Tackling climate change is crucial, and electrifying the vehicular transportation sector is essential to reduce greenhouse gas emissions. Lithium‐ion (Li‐ion) batteries are highly efficient for electric vehicles (EVs) but face challenges such as thermal management, risk of thermal runaway, and high costs of lithium and cobalt. Overcoming these challenges is vital for the widespread adoption of hybrid and EVs. To overcome this drawback, this article proposed a large‐kernel attention graph convolutional network (LKAGCN) with leaf in wind optimization algorithm (LWOA) named as LKAGCN‐LWOA technique, which enhances the thermal management of prismatic Li‐ion batteries by integrating both active and passive cooling techniques. The system incorporates phase change materials (PCMs) with porous‐filled mini‐channels to regulate battery temperature effectively. The LKAGCN analyze thermal properties, battery conditions, and PCM characteristics to predict and optimize the thermal behavior of the battery pack using LWOA. The proposed methods tune the parameters of the hybrid thermal management system, ensuring efficient thermal regulation and improved performance. The proposed method is compared to various existing methods such as convolutional neural network (CNN), Taguchi method, and Finite element model (FEM). [ABSTRACT FROM AUTHOR]

This paper aims at the PCM-based heat sink for electronic cooling. In the present analysis, paraffin wax-based phase change material (PCM), in 3-fin and 4-fin hollow heat sinks with the proper volume of PCM in the temperature of the electronic components can be controlled. The PCM-filled heat sinks are placed on top of the high heat-generating integrated circuit (IC) components. The aim is to reduce the maximum temperature of the electronic components and keep them below their critical temperature, hence increasing the life of the IC chips. A correlation is put forward for dimensionless temperature (θ) in terms of heat flux ( q ∗ ), volume content ( v ∗ ) and size of the IC chips (δ). It has been found that there will be a 4– 6 ∘ C drop in temperature when compared to solid fins heat sinks. It is confirmed that the temperature of the IC chip is a strong function of heat flux, size and volume content of PCM. [ABSTRACT FROM AUTHOR]

With the rapid development of bioscience and technology, wearable electronic devices are developing toward advanced trends such as flexibility, convenience, multifunctionality, and user‐friendliness. Herein, polystyrene‐block‐poly(ethylene‐co‐butylene)‐block‐polystyrene (SEBS) is employed for assisting the strong binding of silver nanoparticles (AgNPs) with polyimide nanofiber (PIF) to obtain the durable PIAgS conductive nanofiber membrane with antibacterial and hydrophobic ability. Owing to the porous fiber skeleton of nanofiber membrane and good interface adhesion, AgNPs can be homogeneously anchored onto fiber surface to construct stable and perfect 3D conductive network with an ultrahigh conductivity of up to 2102.7 S/m, enabling multifunctionality of the resultant conductive nanofiber membrane with superior bioelectric signal (EMG/ECG) sensing, pressure sensing (S = 1.45 kPa−1, 100 kPa) for deep learning assisted gesture recognition, electromagnetic interference (EMI) shielding (18757.8 dB·cm2·g−1), and electric heating (12.2 °C/V2) performances. Furthermore, as a multifunctional wearable electronic device, the antimicrobial ability of AgNPs and breathability of nanofiber membrane can ensure its sufficient wearing safety and comfort. Importantly, the inherent weathering resistance of PINF and SEBS also endows it with excellent stability and broad service life. Taken together, the designed conductive nanofiber membrane possesses great application potential for next‐generation multifunctional wearable electronic device with excellent stability and wide applicability. [ABSTRACT FROM AUTHOR]

Achieving year‐round energy savings in buildings holds great significance toward reaching carbon neutrality and sustainability. Switchable thermal‐management materials offer an energy‐free solution to dynamically regulating internal building temperatures, by passively emitting heat into cold outer space in summer, and absorbing heat from hot sunlight in winter. In addition to dynamic thermal regulation, color display is another pursuit for addressing aesthetic considerations; however, most current dynamically switchable materials lack color options, due to an optical conflict between adaptive solar reflection and selective visible absorption, limiting their wide adoption in aesthetic scenarios such as commercial exterior walls. Herein, a colored temperature‐adaptive cloak (CTAC) that achieves dynamically switchable thermal management in an energy‐neutral way without sacrificing year‐round vibrant color display is reported. This is realized by decoupling solar reflectivity modulation and color display through the choice of two individual constituent components, including thermochromic microcapsules, and fluorescent dyes. Moreover, compared to single‐mode samples with similar colors, the CTAC with dual modes stays 5.6–3.4 °C warmer during cold winter and 14.9–7.9 °C cooler during hot summer (peak solar irradiance: ≈735 and 1030 W m−2, respectively), exhibiting a remarkable potential to achieve year‐round building energy savings. [ABSTRACT FROM AUTHOR]

As modern electronic devices are increasingly miniaturized and integrated, their performance relies more heavily on effective thermal management. In this regard, two-phase cooling methods which capitalize on thin-film evaporation atop structured porous surfaces are emerging as potential solutions. In such porous structures, the optimum heat dissipation capacity relies on two competing objectives that depend on mass and heat transfer. Optimizing these objectives for effective thermal management is challenging due to the simulation costs and the high dimensionality of the design space which is often a voxelated microstructure representation that must also be manufacturable. We address these challenges by developing a data-driven framework for designing optimal porous microstructures for cooling applications. In our framework, we leverage spectral density functions to encode the design space via a handful of interpretable variables and, in turn, efficiently search it. We develop physics-based formulas to simulate the thermofluidic properties and assess the feasibility of candidate designs based on offline image-based analyses. To decrease the reliance on expensive simulations, we generate multi-fidelity data and build emulators to find Pareto-optimal designs. We apply our approach to a canonical problem on evaporator wick design and obtain fin-like topologies in the optimal microstructures which are also characteristics often observed in industrial applications. [ABSTRACT FROM AUTHOR]

The wide spread adoption of heat pipes in automotive and aviation application is hampered by the fact that they require protection against frost damage caused by the repetitive exposure to subzero temperatures. Here, we present heat pipe with ethylene glycol and water as working fluid that can prevent damage to the copper container on exposure to cyclic freezing and thaw. In this research, different mass concentrations of water and ethylene glycol have been tested for freeze protection of heat pipes. Experimental investigations have shown that 3.5% by mass concentration of ethylene glycol in water is able to sustain the cyclic freezing and avoid any damage to the copper pipe. In this research, the freezing and heating cycle is set to operate between -40 °C and 90 °C. Heat pipes used for testing in this research were 6 mm in diameter and 150 mm long with copper fiber spiral wick. Thermal performance tests were carried out on these heat pipes with charging ratio of working fluid varying between 10% to 30% by volume. It is observed that the thermal resistance of heat pipe with working fluid charging ratio in range of 10% to 25% by volume varies from 0.6 °C/W to 0.2 °C/W for the rate of heat transfer of 10 W-50 W. While the charging ratios beyond 25% have shown the higher thermal resistance in the range of 0.8 to 1.0 °C/W for similar rate of heat transfer. All the samples were subjected to 150 freezing and thaw cycles and did not show any signs of frost damage. Accelerated life tests were performed on these heat pipes for up to 500 h and did not presented any signs of degradation in their thermal performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xi'an Jiaotong University is the property of Editorial Office of Journal of Xi'an Jiaotong University 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.)

Researchers have attempted to improve heat transfer in mini/microchannel heat sinks by dispersing nano-encapsulated phase change (NPC) materials in base coolants. While NPC slurries have demonstrated improved heat transfer performance, their applications are limited by decreasing enhancement at increased flow rates. To address this challenge, the present study numerically investigates the effects of wavy channels on the performance of NPC slurries. Simulation results reveal that a wavy channel induces Dean vortices that intensify the mixing of the working fluid and enlarge the melting fractions of the NPC material, thus offering a significantly higher heat transfer efficiency than a straight channel. Moreover, heat transfer enhancement by NPC slurries varies with the imposed heat flux and flow rate. Interestingly, the maximum heat transfer enhancement obtained with the wavy channel not only exceeds the straight one, but also occurs at a higher heat flux and faster flow rate. This finding demonstrates the advantage of wavy channels in management of intensive heat fluxes with NPC slurries. The study also investigates wavy channels with varying amplitude and wavelength. Increasing the wave aspect ratio from 0.2 to 0.588 strengthens Dean vortices and consequently increases the Nusselt number, optimal heat flux, and overall thermal performance factor. [ABSTRACT FROM AUTHOR]

The fast charge and discharge of a battery will significantly increase the overall temperature and thermal difference of the battery, which will further affect the working performance and safety of the battery. Therefore, a heat–fluid coupling topology optimization pipeline for developing radiation performance of the cooling plate is presented to ensure the thermal homogeneity of the battery in this paper. First, the Brinkman penalty model is utilized to construct the solid and fluid structures. Then, a local volume constraint is introduced to create the lattice structure to reduce the temperature difference of the cooling plate. Furthermore, a functionally graded lattice structure via a variable influence radius is presented to improve the radiation performance of the cooling plate when the thermal load is uneven. Numerical experiments are carried out to evaluate the performance of the presented methods on the optimization of the cooling plate, which indicates that the designed cooling plate by the proposed method improves the radiation performance when compared against a traditional straight channel and a SIMP-based optimal design. [ABSTRACT FROM AUTHOR]

Today, energy-efficient resource management is an important task. This study aims to improve the energy efficiency of the cooling system of a technical room by developing a transparent and explainable temperature adaptation tuning algorithm based on the combination of PID control and fuzzy logic methods. This work focuses on the design and development of a hardware and software system consisting of a microcontroller and a temperature sensor. This paper analyzes temperature control based on PID and fuzzy controllers and proposes a combined method to allow for more accurate temperature control tuning. The experimental results show that the combined method reduces the rise time by at least 5%, the stabilization time by at least 17%, and the power consumption by at least 21%. [ABSTRACT FROM AUTHOR]

To protect the environment and reduce dependence on fossil fuels, the world is shifting towards electric vehicles (EVs) as a sustainable solution. The development of fast charging technologies for EVs to reduce charging time and increase operating range is essential to replace traditional internal combustion engine (ICE) vehicles. Lithium-ion batteries (LIBs) are efficient energy storage systems in EVs. However, the efficiency of LIBs depends significantly on their working temperature range. However, the huge amount of heat generated during fast charging increases battery temperature uncontrollably and may lead to thermal runaway, which poses serious hazards during the operation of EVs. In addition, fast charging with high current accelerates battery aging and seriously reduces battery capacity. Therefore, an effective and advanced battery thermal management system (BTMS) is essential to ensure the performance, lifetime, and safety of LIBs, particularly under extreme charging conditions. In this perspective, the current review presents the state-of-the-art thermal management strategies for LIBs during fast charging. The serious thermal problems owing to heat generated during fast charging and its impacts on LIBs are discussed. The core part of this review presents advanced cooling strategies such as indirect liquid cooling, immersion cooling, and hybrid cooling for the thermal management of batteries during fast charging based on recently published research studies in the period of 2019–2024 (5 years). Finally, the key findings and potential directions for next-generation BTMSs toward fast charging are proposed. This review offers an in-depth analysis by providing recommendations and potential solutions to develop reliable and efficient BTMSs for LIBs during fast charging. [ABSTRACT FROM AUTHOR]

Foil bearings are considered to be an excellent fit for a range of high-temperature applications. However, they are susceptible to collapse as a result of thermoelastic instability (TEI). This study introduces a novel approach to enhance passive cooling by adding fins to the surface of the hollow journal cylinder. The effect of enhanced heat transport on the thermoelastic evolution of the bearing surface is thoroughly explored. Furthermore, the critical speed of a foil bearing is derived after taking into account the effect of fins. This affordable method enables the designer to increase the threshold speed of TEI and guard against foil-bearing failure. [ABSTRACT FROM AUTHOR]

The integration of carbon nanomaterials with flexible polymers has received intensive attention as a promising research direction in developing materials with novel properties for advanced applications. Herein, we report on the fabrication and characterization of flexible porous polydimethylsiloxane (PDMS) coated with graphene nanoplatelets (GNPs). We explore the mechanisms affecting its various properties under deformation, and propose new applications for it. The results show lightweight and excellent flexibility characteristics for the obtained GNP-PDMS composite. Measurements of its electrical resistance revealed a change in the electrical resistivity from 2.35 × 106 Ω·m to 194 Ω·m under a strain change from 10 to 80% illustrating its ability to shift behavior from an electrical insulator to a relatively low resistivity material and demonstrating the considerable potential for use as a flexible electrical switch. Moreover, the thermal conductivity of GNP-PDMS was found to be significantly enhanced (up to ∼ 110%) by changing the level of compression from 20 to 80%, proving a strain-tunable thermal performance, allowing its utilization as an insulation material of variable conductance for unique thermal management applications. [ABSTRACT FROM AUTHOR]

Copyright of Automotive Digest is the property of Automotive Digest Editorial Office 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.)