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Advanced design methods and manufacturing techniques are crucial for developing thermal management structures, essential for the efficient operation of complex equipment. This study provides a thorough review of design methodologies and advanced manufacturing technologies for thermal management materials and structures. It identifies key challenges and critically evaluates the integration of innovative design principles, such as biomimicry and topology optimization, into thermal management solutions. The analysis delves into the evolution of design theories and preparation techniques, with a specific focus on modern needs and research directions, particularly highlighting components fabricated using additive manufacturing and their effectiveness in meeting advanced thermal management requirements. Current research focuses on designing structures tailored to various cooling methods, including air‐cooling, liquid‐cooling, heat exchanger cooling, and heat pipe cooling. These designs utilize phase change materials, electrocaloric cooling, and thermoelectric cooling materials to achieve optimal thermal management performance. Additionally, emerging innovations like solid‐liquid mixed heat transfer and the elastocaloric effect are garnering increased interest. Enhancing the design of thermal management structures through rigorous numerical simulations is critical for improving engineering applicability. However, overcoming challenges related to the commercialization and practical utilization of these advanced structures remains a pressing need. [ABSTRACT FROM AUTHOR]

The increasing need for electromagnetic interference (EMI) shielding of electronics in cold environments such as those in aircraft, space exploration, and wearable heaters to avoid hazardous icing conditions or hypothermia requires the development of thin and lightweight EMI shielding materials preferably by absorbing rather than reflecting electromagnetic (EM) waves while also generating heat through energy-efficient electrothermal conversion. However, it is challenging to achieve absorption-dominant EMI shielding and energy-efficient electrothermal heating simultaneously in a thin and lightweight structure. Here, we develop a heterogeneous composite film comprising a porous multi-walled carbon nanotubes (MWCNTs)/bacterial cellulose (BC) film and an aligned MXene/Ag nanowires (NWs) backing via a sequential vacuum filtration process. The porous film contains random conductive networks of MWCNTs with moderate conductivity while the aligned MXene sheets atop Ag NWs network affords high conductivity in the backing, giving rise to graded electrical conductivity for absorption-dominant EMI shielding. The increasing Ag NW coverage leads to significantly increased electrical conductivity without increasing the EM wave reflection as well as the density and thickness of the film, yielding excellent specific EMI shielding effectiveness (> 8500 dB/(g·cm2)), low driving voltage for energy-efficient electrothermal heating (163 °C at 2.5 V), and fast response time (60 s) at a low areal density of 0.015 mg/cm2. Combining EMI shielding and electrothermal heating, the heterogeneous film developed here are promising contenders for the protection of electronic equipment in low-temperature environment. [ABSTRACT FROM AUTHOR]

Heat dissipation significantly limits semiconductor component performance improvement. Thermal management devices are pivotal for electronic chip heat dissipation, with the enhanced thermal conductivity of materials being crucial for their effectiveness. This study focuses on single-crystal diamond, renowned for its exceptional natural thermal conductivity, investigating diamond microchannels using finite element simulations. Initially, a validated mathematical model for microchannel flow heat transfer was established. Subsequently, the heat dissipation performance of typical microchannel materials was analyzed, highlighting the diamond's impact. This study also explores diamond microchannel topologies under high-power conditions, revealing unmatched advantages in ultra-high heat flux density dissipation. At 800 W/cm2 and inlet flow rates of 0.4–1 m/s, diamond microchannels exhibit lower maximum temperatures compared to pure copper microchannels by 7.0, 7.2, 7.4, and 7.5 °C, respectively. Rectangular cross-section microchannels demonstrate superior heat dissipation, considering diamond processing costs. The exploration of angular structures with varying parameters shows significant temperature reductions with increasing complexity, such as a 2.4 °C drop at i = 4. The analysis of shape parameter ki indicates optimal heat dissipation performance at ki = 1.1. This research offers crucial insights for developing and optimizing diamond microchannel devices under ultra-high-heat-flux-density conditions, guiding future advancements in thermal management technology. [ABSTRACT FROM AUTHOR]

Wire arc additive manufacturing (WAAM) is a proven technology in metal additive manufacturing (AM), which can produce large-scale components at a faster production rate. Since WAAM adopts a welding heat source for metal deposition over the substrate, severe thermal gradients develop around the deposition resulting in residual stresses in the substrate, thereby distorting the substrate. In the case of area filling in metal AM processes, heat accumulation is progressive and a large amount of heat is accumulated at the end of the deposition. This leads to thermal imbalance over the substrate and an increase in the shrinkage forces during cooling, thereby causing higher distortion. This paper mainly deals with the mitigation of distortion in the substrate for area filling caused by the thermal imbalance over the substrate. This thermal imbalance is addressed in two ways; a) by selectively insulating and b) by selectively conducting the heat from the substrate. Simulations are conducted to study the thermal evolution during area filling and counterbalance the heat by insulating and conducting the substrate selectively during experimental deposition. A comparative assessment of distortions of the full conduction, full insulation, selective conduction and selective insulation cases is detailed. The selective thermal management strategy showed lower thermal imbalance over the substrate resulting in lower distortion. [ABSTRACT FROM AUTHOR]

Battery packs found in electric vehicles (EVs) require thermal management systems to maintain safe operating temperatures in order to improve device performance and alleviate irregular temperatures that can cause irreversible damage to the cells. Cylindrical lithium-ion batteries are widely used in the electric vehicle industry due to their high energy density and extended life cycle. This report investigates the thermal performance of three liquid cooling designs for a six-cell battery pack using computational fluid dynamics (CFD). The first two designs, vertical flow design (VFD) and horizontal flow design (HFD), are influenced by existing linear and wavy channel structures. They went through multiple geometry optimisations, where parameters such as inlet velocity, the number of channels, and channel diameter were tested before being combined into the third and final optimal design (OD). All designs successfully maintained the maximum temperature of the cells below 306.5 K at an inlet velocity of 0.5 ms−1, meeting the predefined performance thresholds derived from the literature. The HFD design was the only one that failed to meet the temperature uniformity goal of 5 K. The optimal design achieved a maximum temperature of 301.311 K, which was 2.223 K lower than the VFD, and 4.707 K lower than the HFD. Furthermore, it produced a cell temperature difference of 1.144 K, outperforming the next-best design by 1.647 K, thus demonstrating superior temperature regulation. The OD design can manage temperatures by using lower inlet velocities and reducing power consumption. However, the increased cooling efficiency comes at the cost of an increase in weight for the system. This prompts the decision on whether to accommodate the added weight for improved safety or to allocate it to the addition of more batteries to enhance the vehicle's power output. [ABSTRACT FROM AUTHOR]

To establish battery electric vehicles as an attractive alternative to internal combustion vehicles, charging times of 15 min or less are increasingly demanded. This is especially challenging for lower battery temperatures, as this exacerbates the risk of accelerated battery degradation due to lithium plating. Therefore, active battery heating is utilized in state-of-the-art electric vehicles. To evaluate the impact of such heating strategies at vehicle level, we deployed an electrochemical battery model coupled with a longitudinal vehicle dynamics model. Using anode potential control to prevent lithium plating, we assess the time-saving potential versus the energy cost of different preconditioning and fast-charging strategies. The results reveal substantial energy saving and charge speed increase potential through optimal charge-stop planning, preconditioning timing, cost-adjusted thermal management thresholds, and considering driving behavior. This emphasizes the need for advanced operation strategies, taking into account both battery-level electrical and thermal restrictions, as well as vehicle integration and route planning. [ABSTRACT FROM AUTHOR]

A hybrid technique is proposed for electric vehicles (EVs) or hybrid electric vehicles (HEVs) with a battery thermal management system (BTMS). The proposed hybrid method is the combined execution of the Pelican Optimization Algorithm (POA) and Firebug Swarm Optimization (FSO). The hunting behavior of pelicans is improved with the help of the FSO technique; hence, it is named the POA-FSO strategy. Here, a battery of 36 lithium-ion (Li-ion) cells is considered. The proposed method of analyzing battery thermal performance analyzed factors like heat flux from the battery cell to the passage spacing size, cooling air and the cooling air's mass flow rate (MFR). The BTMS performance is studied under maximum battery unit temperature, pressure drop and temperature uniformity. The proposed method enhances the coolant passage spacing and decreases the temperature difference in the battery cells. The proposed approach is executed on the MATLAB platform, and its performance is compared with existing approaches. From the results, it is concluded that the MFR maximizes, and a nonuniform distribution of the MFR of the passage occurs. By using the proposed approach, the maximal temperature change of cooling air among the passages is 2.0 K, the maximal temperature change between the battery cells is 7.5 K and a pressure drop of 228.03 Pa is obtained. [ABSTRACT FROM AUTHOR]

As the plateau environment is characterized by low air pressure and low density, it greatly limits the heat dissipation performance of high-power electromechanical equipment. Especially for new military combat equipment in China, such as hybrid armored vehicles, effective heat dissipation of power batteries is essential for their operational viability in intricate plateau terrains. This paper focuses on the thermal management and heat dissipation attributes of a lithium-ion battery assembly within a military hybrid armored vehicle stationed at an altitude of 4000 m. Firstly, a comprehensive three-dimensional thermal model was constructed for the battery unit to establish an air-cooled dissipation framework. Secondly, the effect of structural parameters of the battery pack, specifically inlet and outlet sizes, quantity, and layouts, on heat dissipation was investigated. The results indicate that larger air inlet and outlet sizes contribute to better battery pack heat dissipation. And using two air inlets and outlets not only leads to lower maximum temperatures but also enhances overall temperature uniformity and cell module temperature consistency. Additionally, the forced convective heat transfer was analyzed by investigating the influence of inlet velocity. It was observed that forced air-cooled is suitable for battery packs with discharge rates below 1.6 C. Strategic optimization of battery pack structural parameters and the adoption of the carrier air-cooled approach can notably enhance battery cooling efficacy in plateau environments. These insights serve as a blueprint for refining battery pack designs to bolster heat dissipation performance, ultimately bolstering stability and reliability in plateau environments. [ABSTRACT FROM AUTHOR]

AbstractThe introduction of highly conductive media to enhance the thermal performance of phase change materials (PCM) is an efficient method to counter the inherently low thermal conductivity of PCMs while retaining its benefits. This article reports the transient thermal performance of PCM in novel finned configurations based on Triplex Tube Heat Exchangers (TTHX). The shape, size, and placement of the constituent fins in the PCM domain are varied, and their effect on the transient melting rate of PCM is studied. Two PCM formulations, RT-82 and RT-35 are evaluated. Pockets within the encapsulation geometry wherein a vortex-like melting pattern of PCM can be facilitated, are identified as factors for expediting the melting process. The best performing configuration resulted in ∼17% (RT-82) and ∼9% (RT-25) reduction in melt duration compared to the baseline configuration. The effects of gravity conditions on the PCM melt process of the best performing and baseline configurations were also studied. [ABSTRACT FROM AUTHOR]

Proper temperature regulation of photovoltaic (PV) modules increases their performance. Among various cooling techniques, phase change materials (PCMs) represent an effective thermal management route, thanks to their large latent heat at constant temperatures. Radiative cooling (RC) is also recently explored as a passive option for PV temperature regulation. In this paper, a heat sink (HS), phase change materials, and radiative cooling are integrated with photovoltaic modules to achieve low and uniform temperature distribution along the PV module and improved performance. Eight different combinations are considered for the proposed system, including HS, PCM, and RC, and their various combinations. The PCM is selected according to the environmental conditions of the selected location. A comprehensive 2-D model is developed and analyzed in COMSOL-Multiphysics software by solving the governing equations using the finite element method. The performance analysis is carried out for the climatic conditions of the Atacama Desert, having high solar radiation and ambient temperature. The effects of PCM height, ambient temperature, wind velocity, and solar radiation on the performance of the proposed system are studied. The performance of eight different configurations is also compared. The maximum reductions in PV temperature, maximum PV power, and a minimum drop in PV conversion efficiency are observed to be 22 oC, 152 W, and 14% using a combined heat sink and radiative cooling systems, among all other configurations. The findings of this study can be used to select the best PV cooling method among different configurations. [ABSTRACT FROM AUTHOR]

AbstractIn this study, we propose an innovative manifold microchannel heat sink (MMCHS) featuring perforated baffle structures, which is specifically engineered to address the thermal management challenges associated with chips that exhibit multiple hotspots. By enhancing the conventional Z-shaped MMCHS, we designed a cost-effective and efficient cooling solution tailored specifically for precise temperature regulation across multiple hotspots. We employed numerical simulation techniques to analyze the flow dynamics and heat transfer properties of the optimized manifold microchannel heat sink (OMMCHS) across various baffle configurations and perforation densities. The findings reveal that the OMMCHS significantly outperforms the traditional Z-shaped MMCHS, establishing it as a superior option for cooling of high-power chips with multiple hotspots. Notably, the OMMCHS configuration equipped with I-type baffles and a 50% perforation rate yields the most favorable results, ensuring temperature homogeneity across the hotspots at an inlet velocity of 1.9 m/s. Compared to the MMCHS, the OMMCHS reduces pump power consumption by up to 77.8% while maintaining the same peak temperature, highlighting its efficiency and effectiveness in thermal management. [ABSTRACT FROM AUTHOR]

The application of smart devices and artificial intelligence (AI) technologies has led to an increase in electromagnetic interference (EMI) issues. Compared with the traditional metal-based EMI shielding materials, lighter and more efficient polymer-based EMI shielding materials have a broader application prospect. In this work, we utilized electrospinning and calcination techniques to synthesize Fe3O4 nanofibers and employed a layer-by-layer assembly method to create a Ti3C2Tx MXene/Fe3O4/carbon fiber fabric/waterborne polyurethane (Ti3C2Tx MXene/Fe3O4/CFf/WPU) composite fabric. Our findings reveal that this composite fabric possesses superior EMI shielding capabilities. Specifically, the FMC12.5–5 composite material, which contains 12.5 wt % Fe3O4 and 5 wt % Ti3C2Tx, demonstrates remarkable electromagnetic interference (EMI) shielding effectiveness (SE) (up to 43.6 dB) at a mere 0.4 mm thickness with a low MXene content. Meanwhile, the fabric achieves a significant anisotropic thermal conductivity of up to 0.46 W/(m K), fulfilling the in-plane thermal conductivity requirement. Additionally, the sandwich-structured composite exhibits excellent mechanical performance (Young's modulus is up to 113.5 MPa and tensile strength reaches 15.7 MPa) and is flexible enough to endure repeated bending, folding, and shaping. It maintains a reliable electrothermal conversion capability, achieving temperatures of up to 106 °C at only 2.5 V. This study has expanded the exploration of enhanced electromagnetic interference (EMI) shielding and electrothermal conversion capabilities. [ABSTRACT FROM AUTHOR]

The continued miniaturization of chips demands highly thermally conductive materials and effective thermal management strategies. Particularly, the high‐field transport of the devices built with 2D materials is limited by self‐heating. Here a systematic control of heat flow in single‐side fluorinated graphene (FG) with varying degrees of fluorination is reported, revealing a superior room‐temperature thermal conductivity as high as 128 W m−1 K−1. Monolayer graphene/FG lateral heterostructures with seamless junctions are approached for device fabrication. Efficient in‐plane heat removal paths from graphene channel to side FG are created, contributing significant reduction of the channel peak temperature and improvement in the current‐carrying capability and power density. Molecular dynamics simulations indicate that the interfacial thermal conductance of the heterostructure is facilitated by the high degree of overlap in the phonon vibrational spectra. The findings offer novel design insights for efficient heat dissipation in micro‐ and nanoelectronic devices. [ABSTRACT FROM AUTHOR]

Electronic systems are used in almost all areas of industry, with an increasing power consumption rate. This trend makes thermal management of electronics compulsory in order for proper operation. Several methods can be employed to examine electronics' thermal behavior. Conduction-based Finite Element Method (FEM) for heat transfer analysis is one of them; providing accurate solutions within short solution times is one of its outstanding advantages. Nevertheless, the fluid inside or around the system, usually air for electronic systems, is not included directly in the conduction-based FEM analysis model. This is an essential deficiency in terms of solution accuracy. If this drawback is overcome, conductionbased FEM will become a preferred analysis method, especially for transient problems under natural convection. In this study, a conduction-based FEM analysis model of an electronic board with two heat-dissipating components inside an enclosure under transient natural convection was developed. The procedure of the model involves the correction of unknown input parameters. An experimental investigation was performed, the results of which were used as reference values for the correction process. These unknown parameters were determined iteratively. The iteration was continued until the results of the analysis and those of the experiment matched. The difference between the results of the analysis and those of the experiment was less than 2-3°C. Some parametrical thermal investigations were performed on the electronic board using the final analysis model. [ABSTRACT FROM AUTHOR]

With the growing demand for new energy batteries and the increasing need for battery thermal management, the heat dissipation performance requirements of water coolers are also becoming more stringent. This research paper concentrates on the study of high energy efficiency of the water chiller system. Based on two aspects of structure and algorithm, refined calculation and selection are carried out.It introduces a linkage control logic based on three adjustable main components (water pump, fan, and compressor). The findings demonstrate that the water chiller with a refined design offers a safer and more stable water cooling system with reduced power consumption. [ABSTRACT FROM AUTHOR]

In this study, we present a new mixed cooling system that combines internal oil with water-cooling, and the effective temperature control of the motor resulted in long-term stable operating conditions. Mass, momentum, and energy equations were obtained by adopting the volume of fluid and moving reference frame methods for an in-depth heat transfer analysis of motor cooling systems. In addition, various cooling systems, such as churning and drop methods were carefully selected by considering the maximum temperature and heat transfer path of the advanced motor. To ensure the reliability of the computational model, the internal thermal resistance of the motor was adjusted based on the analysis results of the reference case. The churning effect facilitated heat transfer through the air gap, thus minimizing the local temperature difference between the rotor magnets and stator coils. The drop effect directly cooled the end coil, thereby resulting in a high cooling efficiency. [ABSTRACT FROM AUTHOR]

In this paper, a beta-phase gallium oxide (β -Ga2O3) vertical FinFET with diamond-gate has been studied by Silvaco-ATLAS simulation. The diamond-gate structure achieves adjustable pin (p-insulator-n) junction owing to the diamond-SiO2-Ga2O3 heterostructure. This design also enhances heat dissipation by virtue of the high thermal conductivity of the diamond. Compared to conventional FinFETs, the diamond-gate FinFET (DG-FinFET) reduces the static operating temperature rise by around 17.30%. Additionally, due to its greater heat dissipation capacity, DG-FinFETs provide a 5.84% increase in current density at 1 kA cm−2 current density level. The structural changes in the diamond-gate also result in a significant reduction in the gate-source capacitance (C GS). At 1 MHz operating frequency and the same gate voltage, DG-FinFETs have 69.29% less gate-source charge (Q GS), 70.80% less charge/discharge delay time, 73.70% less switching loss, and 57.15% less conduction loss. Overall, the simulation and analysis presented in this work indicate a promising advancement of the DG-FinFET structure in high-power and rapid switching applications. [ABSTRACT FROM AUTHOR]

Inorganic hydrated salt phase change materials (PCMs) hold promise for improving the energy conversion efficiency of thermal systems and facilitating the exploration of renewable thermal energy. Hydrated salts, however, often suffer from low thermal conductivity, supercooling, phase separation, leakage and poor solar absorptance. In recent years, compounding hydrated salts with functional carbon materials has emerged as a promising way to overcome these shortcomings and meet the application demands. This work reviews the recent progress in preparing carbon-enhanced hydrated salt phase change composites for thermal management applications. The intrinsic properties of hydrated salts and their shortcomings are firstly introduced. Then, the advantages of various carbon materials and general approaches for preparing carbon-enhanced hydrated salt PCM composites are briefly described. By introducing representative PCM composites loaded with carbon nanotubes, carbon fibers, graphene oxide, graphene, expanded graphite, biochar, activated carbon and multifunctional carbon, the ways that one-dimensional, two-dimensional, three-dimensional and hybrid carbon materials enhance the comprehensive thermophysical properties of hydrated salts and affect their phase change behavior is systematically discussed. Through analyzing the enhancement effects of different carbon fillers, the rationale for achieving the optimal performance of the PCM composites, including both thermal conductivity and phase change stability, is summarized. Regarding the applications of carbon-enhanced hydrate salt composites, their use for the thermal management of electronic devices, buildings and the human body is highlighted. Finally, research challenges for further improving the overall thermophysical properties of carbon-enhanced hydrated salt PCMs and pushing towards practical applications and potential research directions are discussed. It is expected that this timely review could provide valuable guidelines for the further development of carbon-enhanced hydrated salt composites and stimulate concerted research efforts from diverse communities to promote the widespread applications of high-performance PCM composites. [ABSTRACT FROM AUTHOR]

Conductive textiles with electromagnetic interference (EMI) shielding functionality are highly desirable for growing flexibility requirements of EMI shielding devices. Most extant shielding coatings on textiles rely on rigid nanomaterials, which are susceptible to detachment, and generate a great deal of reflected EM waves. Thus, there is a high demand for shielding coatings on textiles that are stretchable, stable, and capable of suppressing the secondary reflection toward incident EM waves. Liquid metal is a particularly suitable candidate owing to its high electrical conductivity and excellent conformality. Herein, a straightforward coating strategy is developed for fast fabrication of Ion/Clay‐F that is reinforced with ionogel encapsulation. Especially, the method enables the direct transformation of fluid‐like liquid metal into a clay‐like state and the preparation of ionogel sealings from monomer solutions. The resulting Ion/Clay‐F exhibits promising features, including high total EMI shielding effectiveness (SET) (highest value of 49.3 dB for a single layer and an average value of 73.0 dB for three layers), low reflectivity (0.404), improved tensile strength (13.16 MPa) and tolerance in a wide range of temperatures (−18–100 °C). Remarkably, such Ion/Clay‐F outperforms pure cotton fabric in terms of thermal management, delivering superior heat dissipation and thermal insulation properties. [ABSTRACT FROM AUTHOR]

With the development of detection and identification technology, infrared stealth is of great value to realize anti-reconnaissance detection of military targets. At present, infrared stealth materials generally have deficiency, such as complex structure, inconvenient radiation regulation and cumbersome preparation steps, which greatly limit the practical application of infrared stealth materials. In view of the above deficiency of infrared stealth materials, we proposed a kind of multilayer film for infrared stealth using VO2 thermochromism based on the temperature response mechanism of tuna to adjust its color, and through the intelligent reversible radiation regulation mechanism to meet the infrared stealth requirements of tanks in different actual scenes. The results show that when the temperature increases from 300 K to 373 K, the peak emissivity of the film decreases from 94% to 20% in the 8–14 µm band after structural optimization, which can realize the infrared stealth of the high temperature target in the 8–14 µm band. The average emissivity of the multilayer film for infrared stealth at 3–5 µm and 8–14 µm band can be reduced to 34% and 27% at 373 K, and the peak emissivity at 5–8 µm band can reach 65%, realizing dual-band infrared stealth in the 3–5 µm and 8–14 µm bands and heat dissipation in the 5–8 µm band. The multilayer film for infrared stealth based on VO2 thermochromism designed by the authors can meet the characteristics of simple film structure, convenient radiation regulation and simple preparation. [ABSTRACT FROM AUTHOR]

Achieving efficient thermal management urges to exploit high-thermal-conductivity materials to satisfy the boosted demand of heat dissipation. It is critical to adopt standardized characterization protocols to evaluate the intrinsic thermal conductivity of thermal management materials. However, for the most representative laser flash method, the lack of standard measurement methodology and systematic description on the thermal diffusivity and influencing factors has led to significant deviations and confusion of the thermal conduction performance in the emerging thermal management application. Here, the measurement error factors of thermal diffusivity by the common laser flash analyzer (LFA) are discussed. Taking high-thermal-conductivity graphitic film (GF) as a typical case, the key factors are analyzed to guide the measurement protocol of related carbon-based thermal management materials. The basic principle of the LFA measurement, actual pre-processing conditions, instrument parameters setting, and data analysis are elaborated for accurate measurements. Furthermore, the graphene thick films and common isotropic materials are also extended to meet various thermal measurement requirements. Based on the existing practical problems, we propose a feasible test flow to achieve a unified and standardized thermal conductivity measurement, which is beneficial to the rapid development of carbon-based thermal management materials. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management 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.)

Lithium-ion batteries still remain a cornerstone for the sustainable transportation by the way of its usage in electric vehicles (EVs). However, their optimal performance hinges on maintaining at consistent thermal conditions especially during operation, and at high discharge rates. The present study proposes a novel mini-channel cooling system specifically designed for a 10 Ah lithium-ion pouch cell. This innovative design incorporates cold plates on both battery surfaces for enhanced heat dissipation. In addition, the efficacy of silver (Ag) and copper oxide (CuO) nanofluid coolants by comparing with traditional water cooling in three distinct battery design configurations was also studied. Design 1 and 2 comprises respectively with partially and fully encased cold plates with mini-channels distributed both segmentally and centrally, and Design 3 the present proposed model featuring a fully covered cold plate with a serpentine flow layout for optimized heat transfer efficiency. Extensive computational analysis using ANSYS FLUENT 18.1 software reveals the superiority of Design 3. Notably, this configuration achieved significantly a lower maximum cell temperature (306.7 K and 305.0 K) with 0.25% and 0.5% Ag nanofluid coolants compared to Design 1 and 2, at a discharge rate of 5C. This underscores the potential of silver nanofluids for superior battery thermal management, particularly within the optimized Design 3 framework. These findings offer valuable insights for developing enhanced battery thermal management systems in EVs. [ABSTRACT FROM AUTHOR]

Copyright of Electric Drive for Locomotives is the property of Electric Drive for Locomotives 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.)

The reliable functioning of next-generation electronic devices within their temperature limits is contingent upon the efficient removal of high heat flux. Interfaces between the device, heat spreaders, and heat sink contribute significantly to thermal resistance in conventional chip packages. The elimination of interface resistances can lead to a noteworthy decrease in overall thermal resistance by incorporating the heat sink directly into the heat-generating device. The current study involved the manufacturing, simulation and experimentation of a micro channel heat sink. The micro channel assembly is manufactured with dimensions of 50 × 50 × 3 mm. The length of micro channel is 35 mm having height and width of 0.2 mm with 58 channels. The experimentation and numerical simulation was done with considering the various parameters like mass flow rate, heat flux, and inlet temperature of nanofluid. The microchannel heat sink improved electronic device thermal performance in fabrication, experimentation, and numerical simulation. The heat sink lowered device temperatures and prevented overheating. Nanofluid at 0.3% volume and at a mass flow rate of 8 m/s, the heat transfer coefficient reaches a maximum value of 13,693.00 W/m2 K at input temperature of 35 °C. The comprehension of the heat sink's performance was enhanced subsequent to the simulations, which unveiled the fluid flow characteristics and heat transfer mechanisms within the microchannels. [ABSTRACT FROM AUTHOR]

The development of energy storage materials is crucial for effective energy management. In this study, we present the creation of a composite material comprising polypropylene (PP) aerogel, paraffin, and multi‐walled carbon nanotubes (MWCNTs) as a phase change material (PCM). Our process begins with the dissolution of PP granules, serving as the foundational step. Subsequently, various antisolvents are systematically employed to induce the formation of PP gels. The process culminates in the fabrication of aerogels through the established freeze‐drying technique. Importantly, our examination of porosity highlights the significant impact of antisolvent selection on the pore structure and specific surface area of the resulting aerogels. Our weight measurements demonstrate the remarkable capacity of the lightweight PP aerogel, characterized by substantial porosity and inherent hydrophobicity, to adsorb paraffin, capturing up to five times its weight. These findings are substantiated through structural analyses, including Fourier‐transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD). Thermal analysis of the PP/PCM/MWCNTs composites reveals the achievement of the highest enthalpy, reaching 125 J g−1, representing a modest 13% reduction compared to pure paraffin. Furthermore, all samples exhibit exceptional thermal stability even after 50 thermal cycles. Notably, Xenon flash analysis (XFA) shows an approximate 800% increase in thermal conductivity compared with pure paraffin and a substantial 35% increase compared to PP/paraffin composites. In conclusion, our lightweight aerogel‐based PCM demonstrates great promise for various thermal management applications. Highlights: Cost‐effective PP aerogel has a great potential for hosting paraffin as PCM.The type of antisolvent could have a huge effect on PP aerogel's structure.PP aerogel/Paraffin/MWCNT could effectively enhance thermal conductivity.Available PP/Paraffin/MWCNT has a great potential for PCM applications. [ABSTRACT FROM AUTHOR]

This study presents a thermoset moulding compound designed for electrical machines with high power densities. The compound reduces residual stresses induced by the difference in thermal expansion during use and by shrinkage in the compound during the manufacturing process. To reduce the internal stresses in the compound, in the electrical sheet lamination and at their interface, first the moulding's coefficient of thermal expansion (CTE) must match that of the lamination because the CTE of the electrical sheets cannot be altered. Second, the shrinkage of the compound needs to be minimized because the moulding compound is injected around a prefabricated electrical sheet lamination. This provides greater freedom in the design of an electric motor or generator, especially if the thermoset needs to be directly bonded to the electrical sheet. The basic suitability of the material for the injection moulding process was iteratively optimised and confirmed by spiral flow tests. Due to the reduction of the residual stresses, the compound enables efficient cooling solutions for electrical machines with high power densities. This innovative compound can have a significant impact on electric propulsion systems across industries that use laminated electrical sheets. [ABSTRACT FROM AUTHOR]

Individual component testing is an integral part of vehicle development and can be performed in multiple stages of the product development process. One such component assembly that often requires extensive testing is the brake system. The brake system is crucial for vehicle safety and, thus, needs to be validated from a functional perspective.A test rig setup to accommodate a brake caliper fixture, as well as a funnel housing an anemometer, was purposefully designed and manufactured. This arrangement allows for measuring brake disc performance, surface temperature and quantifying mass airflow through the disc. The results show that the mass flow of air through the disc vanes highly depends on the disc temperature, but can also vary by more than 10 % for discs with the same specifications. Furthermore, the results highlight non-negligible differences in disc cool-down behaviour based on the braking scenario used to heat the disc up.

The rapid growth in data center workloads and the increasing complexity of modern applications have led to significant contradictions between computational performance and thermal management. Traditional air-cooling systems, while widely adopted, are reaching their limits in handling the rising thermal footprints and higher rack power densities of next-generation servers, often resulting in thermal throttling and decreased efficiency, emphasizing the need for more efficient cooling solutions. Direct-to-chip liquid cooling with cold plates has emerged as a promising solution, providing efficient heat dissipation for high-performance servers. However, challenges remain, such as ensuring system stability under varying thermal loads and optimizing integration with existing infrastructure. This comprehensive study digs into the area of data center liquid cooling, providing a novel, comprehensive experimental investigation of the critical steps and tests necessary for commissioning coolant distribution units (CDUs) in direct-to-chip liquid-cooled data centers. It carefully investigates the hydraulic, thermal, and energy aspects, establishing the groundwork for Liquid-to-Air (L2A) CDU data centers. A CDU's performance was evaluated under different conditions. First, the CDU's maximum cooling capacity was evaluated and found to be as high as 89.9 kW at an approach temperature difference (ATD) of 18.3 °C with a 0.83 heat exchanger effectiveness. Then, to assess the cooling performance and stability of the CDU, a low-power test and a transient thermohydraulic test were conducted. The results showed instability in the supply fluid temperature (SFT) caused by the oscillation in fan speed at low thermal loads. Despite this, heat removal rates remained constant across varying supply air temperatures (SATs), and a partial power usage effectiveness (PPUE) of 1.042 was achieved at 100 % heat load (86 kW) under different SATs. This research sets a foundation for improving L2A CDU performance and offers practical insights for overcoming current cooling limitations in data centers.

With the rapid development of various chips towards high performance and integration, the ‘thermal barrier’ difficulty facing electronic devices has become ever increasingly challenging, while at the same time the space size left for thermal management system already becomes much narrower. In view of the intermittent operation or short-time large power consumption of some electronic devices, the thermal management technology based on phase change materials (PCMs) has received more and more attention. Among those cutting edge PCMs, the liquid metal phase change materials (LMPCMs) especially have aroused much interest due to their outstanding merits in thermal conductivity, energy storage density and stability. In this article, the representative works on LMPCMs are comprehensively reviewed. First, the thermophysical parameters of LMPCMs characterized by high thermal conductivity and large density are summarized. Then, some basic research cases on the thermophysical properties of metallic PCMs that are worthy of further investigation are briefly introduced. In view of the serious supercooling problem of the LMPCMs, the factors affecting the supercooling degree of liquid metal (LM), particularly the thermal history effect, based on the nucleation theory, are presented. Strategies for suppressing supercooling using nucleating agents and crystal species as well as external fields are also introduced. In addition, the mathematical models and related numerical algorithms for interpreting the phase change heat transfer mechanisms of LM are illustrated. Finally, the performance advantages of LMPCMs over other PCMs, as well as the technical approaches to further improve various properties of LMPCM heat sinks, are demonstrated by showing typical application cases. Based on the above, the current research status of LMPCMs and promising future research hotspots are prospected.This review is expected to help researchers interested in LMPCMs to quickly grasp the performance, heat transfer evaluation methods, and research status of LMPCMs, and also to provide a guidance for engineers in related fields to conduct further design and practices.

One of the most critical issues in electric vehicle engineering concerns the thermal management of the battery pack, especially in high-performance applications, which are increasingly demanded by the market. Very interesting, from this point of view, is the study of motorsport applications, almost always characterized by a high ratio between power output and energy stored in the battery pack, which makes the problem of thermal management particularly important. It should be noted that motorsports applications typically have a particularly demanding trend of current discharging and charging from the battery pack, with numerous positive and negative peaks at high c-rates; this obviously produces, due to the Joule effect, a much higher amount of heat per kWh than in conventional road cars and therefore makes efficient and high-performance thermal management very important. In this work was defined, analyzed and optimized an innovative mixed solution with forced air cooling and PCM material (phase change material) for high performance battery modules with cylindrical cells used in a Formula Student car. In the various battery thermal management technologies, Air cooling is one of the most used solutions and can be successfully integrated with PCM cooling technique. In the work proposed here, the optimization and numerical simulation of different solutions and configurations is described. The target parameters considered are: airflow rate, cell spacing and mass of PCM. Fluid dynamic simulations were used to identify the optimal value of the radial gap between the cells, a fundamental construction parameter, and the speed of the air coming out of the fans. The choice of the mass of the PCM sheets was made on the basis of the quantity of heat to be removed to obtain a significant effect on the final temperature of the cells during the test (

Besides the fact that the Proton Exchange Membrane Fuel Cells (PEMFCs) have become the industrial norm of today, the thermal management in PEMFCs is still challenging. Therefore, the present study delves deep understanding of the issue of thermal management and summarizes the relevant research studies that evaluate the efficiency of serpentine flow fields (SFFs) to other flow configurations for thermal management in PEMFCs. The current research explores the variety of aspects of SFFs i.e., temperature uniformity, cooling efficiency, pressure drop, and overall thermal performance to guide future design optimizations and practical implementations of SFFs. The study in hand also discusses developments in SFFs such as., Multi-Pass Serpentine Flow Fields (MPSFFs) and new hybrid designs that include a combination of traditional serpentine and other flow patterns to decrease pressure drop and increase net performance. The findings of various studies show that serpentine flow fields outperform alternative designs in coolant distribution, heat transfer efficiency, and operating temperature stability. Based on the findings, the present study recommends future research options, highlighting the need to include economic and environmental concerns in flow field (FF) design, as well as investigating the use of developing materials and technologies to improve PEMFC performance.

In this paper, we address robotic haptics with the following question: is it possible to design a heating/cooling system that can fulfill both the necessity of keeping the inner robot actuators at a desired optimal heat and, at the same time, use actuators energy loss in terms of heat conveyed, through a soft robotic cover, as pleasant thermal sensation to a human when the robot is touched? We propose a solution to address this question in terms of mechatronic design. Indeed, internal heat generated by actuator loss can be transferred to the robotic haptic cover and a cooling tank for thermal display purposes. A suitable switching control strategy is divided to fulfill the double objective of keeping the actuators’ temperature under a given threshold whilst displaying the desired temperature to the soft robot’s cover. We assess our ideas with an experimental set-up using one actuator and our original soft cover technology with a preliminary user study.

To realize the efficient storage and conversion of solar energy by phase change materials (PCMs), low photothermal conversion efficiency and poor heat transfer performance remain great challenges. Herein, polyethylene glycol (PEG)-based composite PCMs with excellent photothermal conversion performance and exceptional thermal management capability were obtained by using boron nitride/copper oxide@multi-walled carbon nanotubes (BN/CuO@MWCNTs) as the thermal conductive and photothermal conversion enhancement fillers. The results indicate that owing to the bridging effect, the introduction of CuO and MWCNTs on the BN surface can construct additional heat transfer paths, resulting in a high thermal conductivity of up to 2.35 W/(m·K) for the as-prepared PEG/BN/CuO@MWCNTs composite, which is about 9-folds enhancement than pristine PEG. Simultaneously, the supercooling degree of PEG in PEG/BN/CuO@MWCNTs is effectively suppressed due to the synergistic nucleation effect of BN, CuO and MWCNTs. Additionally, the PEG/BN/CuO@MWCNTs composites not only exhibit a high latent-heat capacity of 154.5 J/g and a high photothermal conversion efficiency of 92.2 %, but also show favorable shape stability and durable reliability. This work offers a workable solution for the synergistic enhancement of photothermal conversion and thermal management, which can effectively promote the practical application in solar energy conversion and storage.

This study investigates the complex thermal-fluid behavior within a tilted porous enclosure filled with a Cu−Al2O3-water hybrid nanofluid, subject to segmented magnetic fields, wavy cooling segments, and distributed heat sources. The research explores the intricate interplay between geometric factors and thermal-magnetic forces to enhance heat transfer in industrial applications. The finite volume method (FVM), coupled with the SIMPLE algorithm and a TDMA solver, is employed to solve the governing transport equations. A comprehensive parametric analysis examines the effects of key dimensionless parameters: Darcy-Rayleigh number (10–104), Darcy number (10-4–10-1), Hartmann number (0–70), magnetic field angle (0°-180°), nanoparticle volume fraction (0–2 %), porosity (0.1–1.0), wavy cooler undulation height (0–0.3), magnetic segment width (0–1), number of segmental magnetic fields (0–4), and enclosure tilting angle (0°–180°). The study elucidates the physical mechanisms underlying the transition from uniform to segmented heating scenarios. Results reveal a remarkable enhancement of up to 38 % in heat transfer performance when transitioning from a conventional square enclosure to the proposed configuration with partial waviness on opposing walls. This improvement stems from increased surface area and disrupted thermal boundary layers, promoting better fluid mixing. The application of a segmented magnetic field with strategic orientation resulted in up to 26 % enhancement by modulating flow patterns and creating localized convection cells. The segmented heating generates thermal plumes that interact with the magnetic field-induced Lorentz forces, further improving thermal transport. The findings provide valuable insights into the design and optimization of efficient heat transfer systems in various industries, including electronics cooling, solar thermal collectors, and nuclear reactors, demonstrating significant potential for energy savings and improved thermal management through the strategic integration of hybrid nanofluids, magnetic fields, and geometric modifications in porous media applications.

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.

Flat heat pipes (FHPs) with rectangular groove wick structures fail to sufficiently uplift the working fluid’s liquid meniscus to cover the upper sides of the groove walls due to the vertically flat wall design. This results in the formation of non-evaporative zones, particularly in the evaporator region, leading to elevated wall temperatures at high heat loads. To address this issue, a novel FHP with elliptical grooves as wick is designed and tested across heat loads ranging from 30 to 360 W. Elliptical groove depths of 0.5 mm and 0.7 mm are evaluated and compared to FHPs with rectangular grooves. Results showed that at 360 W, the 0.7 mm depth elliptical grooves resulted in 6.5 % reduction in evaporator wall temperature and 27.8 % reduction in thermal resistance, along with 31.5 % enhancement in effective thermal conductivity compared to rectangular grooves. The curvature of the elliptical grooves, combined with enhanced surface tension effects of the working fluid, efficiently uplifted the liquid meniscus to cover the upper wall of the groove, minimizing non-evaporative zones. Additionally, FHPs with elliptical grooves demonstrated lower entropy generation, indicating higher thermal efficiency. Consequently, FHPs with elliptical groove designs are concluded to be an efficient and suitable solution for the thermal management of miniaturized electronic devices.

In an effort to reduce the charging time of electric vehicles (EVs), the thermal management of the charging system has emerged as one of the most urgent issues. The charging rate has been restricted to avoid thermal failure especially in charging cable. Recently, a direct contact cooling technique that utilizes subcooled flow boiling for charging cables has been proposed and has shown promising thermal management performance. However, there has been a lack of clear explanation regarding its thermal characteristics due to its intrinsically complicated flow features. This study investigates the thermal characteristics of subcooled flow boiling in a horizontally aligned concentric annular tube intended to simulate the direct contact cooling technique employed for charging cables. For the experimental investigation, the wall temperature measurements and high-speed flow visualization images acquired from the transparent test module annulus, with inner and outer diameters of 6.35 mm and 22.0 mm, were utilized. Three key axial thermal characteristics of subcooled flow boiling in annulus have been analyzed, and they are flow regime transition, variation of heat transfer mechanisms, and occurrence of critical heat flux (CHF). The transition of flow regimes and the variation of dominant heat transfer mechanisms in the axial direction are mutually influencing due to the coupled effects between the hydrodynamic and thermal characteristics of simultaneously developing flows. The flow regime changes from partially developed boiling (PDB) to fully developed boiling (FDB) as the intensities of nucleate boiling and bubble recondensation vary in the axial direction, while the dominant heat transfer mechanism shifts from single-phase convection to nucleate boiling, corresponding to the flow regime transition from PDB to FDB. The departure from nucleate boiling (DNB) type CHF is observed, manifested by the wavy interface propagating from the far downstream to the upstream region, and the intensities of nucleate boiling and bubble recondensation are also identified as the dominant parameters in determining the occurrence of CHF. Charging time estimation reveals that the proposed method can achieve an 80 % charge for 100-kWh EV batteries in 98 s, while maintaining the cable wire temperature below the safety limit of 80 °C. This strongly supports its potential as a promising thermal management technique for future ultra-fast charging systems.