Efficient thermal management is a critical challenge in the design of modern electronic devices, where compact geometries and high heat fluxes demand advanced materials and simulation strategies. This study addresses this challenge by investigating phase change material (PCM)-filled aluminum honeycomb structures as a promising solution for passive thermal regulation in electronics. A multi-scale modeling framework is developed, coupling a representative volume element (RVE) with sub-modeling techniques to evaluate and improve the thermal behavior of these composite systems. Finite element-based RVE simulations are employed to derive homogenized, temperature-dependent thermal properties—including orthotropic thermal conductivity, density, and specific heat—capturing the macroscopic heat transfer characteristics of the structure. The model incorporates nonlinear material behavior and latent heat effects under transient thermal conditions with time-dependent Dirichlet boundary conditions. The homogenized panel model consisting of multiple unit cells completes its simulation within a few hours, whereas the refined RVE submodel requires a shorter runtime. In contrast, a fully detailed representation of the entire panel would contain several million elements, making direct simulation computationally impractical.The homogenized model effectively predicts global thermal behavior, including temperature evolution and charging/discharging cycles. To resolve localized thermal gradients driven by PCM distribution, an embedded sub-modeling strategy enhances local accuracy without sacrificing efficiency. This coupled modeling approach is particularly well-suited for the design and enhancement of thermal management systems in electronic devices. It offers reduced computational time, scalability, and adaptability—enabling rapid, accurate simulations for parametric studies and real-time evaluations in applications such as power electronics, data centers, and portable consumer devices.

The efficiency of photovoltaic (PV) solar panels decreases with increasing operating temperature, necessitating effective thermal management solutions. Phase change materials (PCM's) have shown promise in passively regulating temperature through their high latent heat capacity. However, the inherently low thermal conductivity of PCM, as highlighted in our previous work, limits its effectiveness and may lead to increased solar cell temperatures compared to systems without PCM. This study addresses this challenge by enhancing PCM thermal conductivity through the incorporation of randomly oriented short carbon fibers. To model the thermal behavior of the composite PCM-carbon fiber medium, a homogenization technique is employed, reducing computational effort while maintaining accuracy. A three-dimensional transient thermal finite element (FE) model has been developed to examine the spatial thermal behavior of the PV panel, addressing the limitations of earlier onedimensional models. The numerical homogenization model is coupled with the FE model to perform optimization analysis, identifying the ideal carbon fiber volume fraction that enhances thermal conductivity while preserving the PCM's latent heat storage capacity. The optimized PCM-carbon fiber system offers a scalable solution for passive thermal management in PV panels, with increased thermal conductivity of the composite medium between 47 % in the solid and 75 % in the liquid state. By reducing peak temperatures, the system enhances energy conversion efficiency and prolongs the operational lifespan of PV cells. The results demonstrate that the passively cooled system reduces the panel's maximum temperature from around 72.5 degrees C to approximately 57 degrees C, leading to a daily efficiency improvement of approximately 0.61 % and an enhancement of 4.6 Win daily electric power output. By significantly reducing peak temperatures and improving transient thermal response, the optimized design ensures efficient heat redistribution, addressing thermal hotspots and maintaining panel performance. This study underscores the potential of carbon fiber-enhanced PCM for advanced thermal management in PV applications, offering a computationally efficient and effective solution for energy-efficient solar panels.

This study focuses on practical considerations regarding Phase Change Materials (PCMs) for energy-efficient buildings in Kuwait's hot climate. Its objective is to fill gaps in the existing literature by providing experimental validation, which has been lacking in previous research that heavily relies on numerical simulations. The selection of a PCM with an appropriate melting point is crucial to achieve balanced melting and solidification cycles. To address this, two identical portable cabins were constructed at the Australian University of Kuwait. One cabin served as the base case, while the other was used to investigate various energy-saving methods. Indoor weather and energy monitoring devices were installed, enabling the collection of wall and roof temperature data at 10-minute intervals. Analysis of the temperature distribution revealed that a PCM with a melting point of 24 degrees C remained in a melted state for approximately 8 h and solidified for 16 h within a 24-hour cycle, particularly on the hottest days in Kuwait. Furthermore, a TRNSYS Type399 PCM model was developed to examine the impact of PCM parameters on the annual energy performance index of the portable cabins. The results indicate that utilizing a PCM with a melting point of 24 degrees C on interior walls and ceilings can result in annual energy savings of up to 20 %, while the thickness of the PCM does not significantly affect performance. In a broader context, this research seeks to tackle the real -world challenges linked to the deployment of PCMs in energyefficient buildings within Kuwait's hot climate. It highlights the significance of confirming findings through practical experimentation aimed at improving the utilization of PCMs.

A numerical modeling methodology based on the finite element method is utilized in this investigation to predict the impact of the PCM characteristics on the system cooling performance and the solar module output power. The thermal analysis considers the transient nature and the nonlinearity of the problem. The boundary conditions include the cyclic variation with time of solar irradiance and ambient temperature in a hot climatic region, with peak temperatures close to 50 degrees C. Under these circumstances and owing to the various influencing parameters, choosing an appropriate PCM is a challenging task. By allowing the PCM characteristics to vary continuously over the applicable domains and not just by giving specified discrete values, a systematic approach is adopted in this work. This technique is applied to explore the relationships between system input parameters, as defined by the PCM properties, and output variables, as described by cell temperature and module efficiency. Due to the harsh boundary conditions, the obtained results demonstrated that PCM with high thermal conductivity is required to achieve efficient thermal regulation. The enhanced material characteristics can only be provided by composite PCMs with graphite or metal additives. The resulting optimized design variables of the suitable PCM, melting temperature, thermal conductivity, and thickness, can reduce the cell temperature to 57 degrees C (20% reduction). The corresponding efficiency and power output are raised by around 8%. The power output was found to increase from 125 W (reference case) to 135 W for the optimized case. The results suggest that using a passive cooling system based on PCM is a viable method for enhancing the power output of a solar PV module. The created coupled model predicts the thermal behavior of the PV module and significantly facilitates the PCM selection procedure to ensure its applicability.

The integration of a composite of porous medium with phase change material (PCM) offers significant advantages in thermal management systems, enhancing heat transfer efficiency and addressing various thermal regulation challenges. This approach utilizes the PCM's latent heat absorption and the enhanced thermal conductivity provided by the porous medium, resulting in optimized system performance. Its applicability spans across electronics cooling and building insulation systems. However, predicting the thermal behavior of this composite material is challenging, necessitating computational tools to anticipate its response under different conditions and evaluate its influence on cooling strategies. The objective of this study is to create a computational tool specifically tailored to evaluate constitutive parameters of this composite material, thereby providing a comprehensive description of its thermal behavior. To achieve this goal, the multiscale homogenization principle is employed to assess the composite's effective thermophysical material properties using the representative volume element approach. The repeating unit cell of the aluminum lattice is incorporated into the PCM to define a representative volume element. The finite element method (FEM) is utilized to solve the three-dimensional homogenization problem, yielding an orthotropic effective thermal conductivity due to the inherent symmetry of the repeating material cell. Moreover, the study leverages the apparent heat capacity method to effectively manage the phase transitions within the PCM domain, utilizing smooth and temperature-dependent functions to accurately describe the thermophysical properties of the PCM. Integrating the composite into battery pack thermal management, this study thoroughly examines thermal dynamics by comparing outcomes with and without PCM integration. The transient thermal problem is accurately tackled using the FEM, employing the evaluated effective constitutive parameters of the homogenized composite to minimize computational effort. The results indicate a notable decline in the highest temperatures of the battery pack, leading to a reduction of about 14 °C at the specific moment when the phase change material fully transitions into its liquid form. The obtained results emphasize the effectiveness and practical feasibility of the proposed thermal management strategy. The modeling approach presented provides a robust tool with significant efficiency in reducing computational time for analyzing the thermal behavior of large models, as the utilization of the homogenization technique notably decreases the computational time.

The integration of phase change materials (PCMs) presents a promising possibility for enhancing the thermal management of supercapacitors (SCs), which are vital components in various energy storage systems. This research focuses on investigating the thermal behavior of SCs with integrated PCM, employing finite element method (FEM) simulations to solve the transient thermal problem. Through a comparative analysis at various time instants, the transient thermal response of SCs is examined, shedding light on the efficacy of PCM-based thermal management strategies. Moreover, parametric studies are conducted to investigate the influence of PCM key characteristics, like melting temperature and layer thickness on the SC thermal response. Additionally, the impact of enhanced PCM thermal conductivity is explored by integrating high-conductive short carbon fibers (CF) within the PCM matrix. This investigation encompasses various PCM melting points, allowing for a comprehensive understanding of the interplay between PCM properties and SC thermal response. The results indicate that a notable decline in the highest temperatures of the SC can be achieved, leading to a reduction of about 9 degrees C depending on the PCM melting temperature and the improved thermal conductivity. The obtained results emphasize the effectiveness and practical feasibility of the proposed thermal management strategy. The modeling approach presented provides a robust tool with significant efficiency in reducing computational time for analyzing the thermal behavior of large models, as the utilization of the homogenization technique notably decreases the computational time. The findings of this study not only provide insights into optimizing PCM-based thermal management strategies for SCs but also contribute to advancing the design and performance of energy storage systems by addressing crucial thermal challenges.

Due to the extremely sweltering weather conditions in Kuwait, residential buildings accounted for 45% of total electricity demand in 2021. To help reduce this demand, phase change material (PCM) was used, and its effectiveness was experimentally investigated. Two identical cabins were constructed at Australian University in Kuwait; one served as the base cabin, while the other was equipped with PCM on all walls and the roof. Both cabins were fitted with 1.5-ton air conditioning systems. The similarity of the two cabins was confirmed by assessing their temperature and power consumption profiles before implementing PCM. Two scenarios were introduced to experimentally examine the passive and active performance of PCM in terms of thermal comfort and energy savings in wintertime in Kuwait. In the first scenario (passive scenario), the air conditioning systems were turned off, and the efficacy of PCM on thermal comfort was assessed through experimental temperature measurements in both cabins during January, February, and March 2024. The cabin with PCM not only remained cooler during the daytime but also stayed warmer during the nighttime. However, the extent of the cabin's warmth and coolness depended on the amount of PCM gradually added wall by wall. With PCM applied to one wall, the cabin remained 2.75 degrees C cooler during the daytime. Adding PCM to two and three walls subsequently resulted in the indoor temperature being reduced by 3 degrees C and 4.5 degrees C, respectively. When all walls were equipped with PCM, this difference increased to 5 degrees C during the daytime. Furthermore, by adding PCM to the roof, the indoor temperature of the PCM-enhanced cabin was up to 5.75 degrees C cooler than the base cabin. During the night, the PCM-equipped cabin remained up to 2.75 degrees C warmer than the base cabin. In the second scenario (active scenario), the air conditioning systems were turned on in April to maintain the indoor temperature of both cabins at a setpoint temperature of 20 degrees C. Daily electricity consumption was monitored for both cabins. The results revealed that the PCM-enhanced cabin consumed less energy, saving between 9.8% and 28.9% of daily electricity compared to the base cabin. Overall, the PCM-integrated cabin improved thermal comfort during the winter months of January to March 2024 without using air conditioning and saved 15.9% on electricity consumption compared to the base cabin in April 2024.

This study develops a thermal homogenization model for an aluminum honeycomb panel using the representative volume element (RVE) concept, considering the orthotropic nature of the structure. The RVE thermal homogenization method is a numerical approach for analyzing heterogeneous materials. It employs a constitutive model based on RVE performance to represent thermal behavior. Effective parameters are determined through averaging techniques, and the finite element method solves the thermal problem, accounting for structure topology and material behavior. The resulting heat conduction problem is solved using the finite element method (FEM) to evaluate the effective thermal characteristics. A 3D RVE is generated based on the honeycomb panel's geometry, evaluating thermal conductivity tensor and describing the medium's thermal performance. Numerical tests validate the model by comparing it with the real honeycomb structure under sinusoidal heat flux. Results show good correlation, with maximum temperatures of 1101.9 °C in the real structure and 1096.4 °C in the medium. The homogeneous medium is further used to investigate thermal performance under convective conditions with varying panel thicknesses, achieving over 77 °C temperature reduction with the thickest panel. Natural vibration behavior is considered, demonstrating strong correlation between modal responses and natural frequencies. This modeling approach efficiently analyzes thermal behavior in large honeycomb structures, reducing computational time significantly.

This research aims to enhance the comprehension of choosing efficient phase-change materials (PCMs) for energy conservation in buildings and addresses the gap in the literature concerning methodologies specific to Kuwait's context. A range of PCM materials, such as solid-state paraffin and liquid-state salt hydrates, have been developed. Eutectic mixtures, organic and inorganic PCMs, as well as bio-based PCMs, are gaining increasing popularity. Nonetheless, the transportation of liquid PCMs in Kuwait is challenging and expensive. In contrast, Graphite-based PCMs, which are in a solid state, provide a feasible transportation solution. This study aims to address the choice of melting point PCMs for buildings and practical considerations related to nano-graphite-based PCMs. Currently, there is a lack of a methodological approach in the literature for selecting the most effective PCM for buildings in Kuwait. To investigate this, two identical portable cabins were constructed in Kuwait, using 75mm sandwich panels with interior dimensions of 2m × 2m × 2.8m. Each room used a split unit air conditioner, with the temperature set at 22°C during measurements. A data logging system with SD memory storage collected temperatures from the interior sides of the cabin walls every 10 minutes between June 27th and July 2nd, 2023. The frequency distribution of wall temperatures from 20°C to 29°C was analyzed. From the results, a PCM with a melting point of 24°C would take approximately 8 hours to melt and have 16 hours available for solidification, considering a 24-hour day/night cycle. The next question to be addressed is determining the appropriate thickness of PCM to be used in Kuwait.

This study analyzes the performance of phase change materials (PCMs) to control and optimize energy in buildings. The utilization of PCMs could decrease energy consumption and enhance indoor thermal comfort of occupants in buildings. For this purpose, a computational model-based optimization is developed to estimate the thermal behavior of a multilayer wall of the building envelope in hot climate locations. The finite element model is coupled with design exploration tools based on design of experiments methodology to investigate the thermal behavior of PCMs under various parameters such as PCM thickness and location as well as melting temperature and melting zone is implemented in the computational model for a simulation period of 10 days. Optimization analysis is conducted using ANSYS software to obtain a set of PCM thermophysical and geometrical parameters which minimize the heat flow into the building. The simulation was carried out for 10 days and the findings of this study showed a reduction by 80% in the heat entering the building when using PCMs. The analysis shows the possible application of PCMs as a mechanism to improve the thermal performance of the building envelope and decrease energy consumption in hot climate regions.

The optimal use of phase change materials (PCMs) in multilayer constructions in hot climates is taken into account in this study. PCMs could reduce energy use and improve indoor thermal comfort by being added to the building envelope. To achieve this, an optimization-based numerical model is created to predict the thermal behavior of a multilayer wall of the building in a hot environment. The finite element model is coupled with design exploration tools based on design of experiments methodology and the response surface technique to analyze the relationships between the influencing PCM parameters and the response variable, which is represented by the heat flow into the internal space. Optimization analysis is carried out to identify a set of PCM thermophysical and geometrical parameters which minimize the output variable. The set of input parameters that includes the PCM thickness and location as well as melting temperature and melting zone is implemented in the computational model for a simulation period of 10 days. The achieved results show a decrease in the maximum temperature at the internal wall compared to the original wall without PCM, with <20% of the heat entering the occupant area. The analysis demonstrates the potential utilization of PCMs as an approach to enhance the thermal characteristics of the building and decrease energy use in regions with high temperatures.

Because of its high efficiency, fuel flexibility, and high-quality waste heat for cogeneration requirements, the solid oxide fuel cell (SOFC) is a potential fuel cell type for power generation in a variety of applications. High working temperatures provide these benefits, but they also come with drawbacks, such as restrictions on the operating environment, problems with thermal management, long on/off times, and the issue of selecting appropriate materials to assure compatibility of the physical material properties of the fuel cell stack components. However, the elevated process temperatures of the SOFC system result in technical challenges. The heat-up stage is a critical issue for the SOFC stack, since the transient process conditions lead to thermal gradients which are combined with material gradients. The result is a mismatch in the thermal–mechanical material behavior inducing high thermal stresses, which in turn affect the functionality of the fuel cell stack. In the SOFC stack under consideration, a glass ceramic joint is used to ensure reliable sealing between cells. This region is identified to be at risk, due to high thermal stresses. In this study the computational modeling approach is applied to predict the thermal-structural response of the stack components to different heat-up strategies and investigate the system with respect to fuel cell temperature, thermal gradients, and induced stresses. Computational thermal and structural results for time dependent heat-up speeds are presented and compared. Essentially, running the process with a constant speed would not provide an optimized solution. Instead, the obtained results show that the heat-up speed should be adjusted to achieve the desired state of fuel cell temperature, reduced thermal gradients and stresses. This target can be met by applying mathematical modeling approach, since experimental analysis are time and cost consuming.

Finite element analysis was utilized in this investigation to study the effect of varying the direction of the laser scan on the thermo-mechanical behavior of a multi-layer additive manufacturing (AM) process. The effect of varying the direction of laser rastering on the temperature distribution, strain, stress and deformation was analyzed in this study. Two laser rastering strategies were considered, namely, (a) counter-clockwise (CCW) for each of the layers deposited and, (b) alternating (CCW followed by clockwise) for each successive layer using a well-validated model. The results showed that for the geometrical configuration under consideration in this study, thermal strains were not significantly impacted by the rastering direction of the laser (CCW is lower than alternating by 8–9%). However, altering the direction of rastering leads to a 45–75% reduction in the deformation values as compared to the CCW mode. This co-relates well with the 10% difference in the maximum thermal gradient of the alternating case compared to the CCW case. The von Mises stress was found to be higher in the CCW mode as compared to the alternating mode. The findings of this investigation illustrated that the location of maximum shear stress depended on the direction of the laser rastering and followed the same trend observed in the thermal strain and the normal von Mises stress. Hence, the CCW mode was found to exhibit higher shear stresses compared with the alternating mode. This study clearly shows that the rastering direction of the laser beam has a profound effect on the thermo-mechanical behavior of the parts manufactured using AM processes.

Fused deposition modeling (FDM) is an advanced additive manufacturing (AM) method for rapid prototyping technique and to produce functional components with complex geometry. However, the process is mostly appropriate to polymer-based raw materials for several fields of application. In this study, a 3-D computational model is developed to analyze the transient heat transfer problem and investigate the inter-layer adhesion behavior, which affects the mechanical behavior of the final part. The developed model is validated based on published experimental and analytical data. The numerical model is utilized to predict the temperature evolution in the interface region between layers. The time history of temperature is coupled with a mathematical model describing the bonding potential to predict the bonding formation. In addition, the developed model is combined with design exploration tools to investigate the relationship between key process parameters and their impact on the output variables using design of experiment (DEO) and response surface methods. Moreover, due to the 3-D nature of the developed model, it could be coupled with a structural computational tool for further thermomechanical analysis.

A three-dimensional finite-element model for the thermal behavior of a supercapacitor was investigated numerically for various pertinent parameters. The parameters included the thermal conductivity of the insulating layer, total heat transfer coefficient, and heat generation rate. In this study, the supercapacitor temperature distributions were obtained under both steady and transient conditions. The results reported in this investigation illustrate that the maximum temperature occurs in the core of the supercapacitor and decreases toward the external surface. Furthermore, the core temperature was found to increase rapidly with an increase in the heat generation rate (charge/discharge current), which requires designing a cooling system that meets the safety and reliability of power systems. Thus, the results presented in this investigation may be used to determine the required cooling system for actual applications of supercapacitors.

The increasing attempt for energy saving in buildings needs the precise estimation of the thermal characteristics of buildings. In order to accomplish this goal, it is very important to conduct a transient thermal analysis of the building. However, the prior knowledge of the thermophysical properties of the building walls is essential to predict its thermal performance. Particularly when investigating existing and old buildings, for the case of renovation, wall materials and their thermal properties might be uncertain. To resolve this problem, the thermophysical properties are evaluated based on data obtained by in situ measurements of surface temperature and heat flux. Problems including complex geometries, which lead to thermal bridging effects, require more realistic, two or three-dimensional models to account for these effects. Therefore, the first objective of this study is to review the existing models available in the literature to investigate the thermal performance of buildings. The second objective is to present a numerical model for estimating the thermophysical properties of the building walls. The optimization process is integrated into the finite element analysis for solving one and two-dimensional coefficient inverse problems of heat transfer. The model is used to obtain the thermo-physical material properties of an equivalent wall, which provides a matching to the thermal flux behavior of an original multilayer wall under the same transient thermal boundary conditions and accounts for thermal bridges. The model presented in this investigation is considered promising to estimate the thermophysical properties of equivalent walls.

Solid oxide fuel cells (SOFC) are suitable for on-board electricity generation as Auxiliary Power Unit (APU) to support the electric power supply in heavy-duty vehicles. In order to satisfy the requirements of a lightweight fuel cell stack for mobile applications, thin-walled components must be used for the stack structure. This necessity is associated with material, process and design difficulties that must be solved in order to achieve a successful utilization. In this work a novel lightweight SOFC stack design with metal-supported cell was studied both numerically and experimentally. The metallic components are made from the Intermediate Temperature Metal (ITM), a high performance, high chromium ferritic stainless steels alloy. The multiphysics modeling approach (fluid dynamics, heat transfer, structural mechanics) was utilized in this work to predict the temperature distribution and the thermo-structural behavior of the new developed design. Geometric details of the fuel cell stack components as well as appropriate nonlinear, temperature and time-dependent constitutive models were developed to describe the material behavior. Experimental data were used to determine the material model parameters and validated the simulation results. The three-dimensional stress and deformation distributions in the individual stack components were evaluated and their maximum values for elements at risk were identified. Thus, the developed model enables the investigation of sustainability and serviceability of the structural elements to ensure a reliable operation of the stack. The developed computational model can be used as a design tool for parametric studies and optimization analysis to investigate the effects of process boundary conditions, material properties as well as geometrical design parameters and their variation on the induced thermal stresses.

Additive manufacturing (AM) process is associated with building up parts in layers using 3D printing technology. The term “3D printing” is fundamentally utilized in the literature as a synonym for Additive Manufacturing. Power Bed Fusion (PBF) and Direct Energy Deposition techniques are two popular AM techniques where parts are manufactured layer by layer using a source of energy to fuse successive layers together. Due to non-homogeneous heating and cooling that occur in such AM processes, residual stresses and anisotropic material properties are the most common issues that might affect the quality and reliability of the manufactured objects. Therefore, knowledge of the thermal history of the parts during manufacturing process is significant. In this investigation, a finite element model using commercial software (ANSYS) is developed to model transient heat transfer process in an object during laser additive manufacturing process. The laser is modeled as a moving heat source with a Gaussian energy distribution. The effects of varying the laser scan speed, direction of the laser speed as well as phase change (melting/solidification) on the temperature variations are analyzed in this study. Moreover, temperature dependent thermal properties (such as thermal conductivity, density, and enthalpy) are considered in the model. More complexity was added to the geometry by simulated the building of a half cylinder as compared to straight layers normally used in similar studies. Simulation results were validated against the experimental results found in the literature. A mesh sensitivity analysis was conducted. It is anticipated that the results of this study will help better understand the effect of additive manufacturing process parameters on the quality and properties of manufactured objects.

3D multiphysics modelling of fuel cell components and fuel cell systems has been a core research field since many years. Current focus has been to support the commercialisation of the technology. Especially, gaining detailed information about the durability and life duration of the utilised fuel cell systems is of paramount importance. As a fuel cell system consists of many components like the fuel cell stack, reformer, afterburner, heat exchanger etc., it is important to account for the coupled processes, occurring within each component and their interaction with the neighbour components. To interpret the long-term reliability of the system, the thermomechanical fatigue behaviour of the critical system regions have been investigated in detail to predict and understand the durability under cyclic load. The life expectation of a system has been predicted using a 3D full scale system level multiphysics model based on coupled CFD-FEM.