Explore the vast range of titles available.

The advent of three-dimensional stacked chips has significantly enhanced overall performance but introduced challenges in thermal analysis. To ensure the reliable operation of stacked chips and improve the design efficiency of heat sinks, a comprehensive exploration of thermal management issues, the formulation of practical thermal design principles, and the development of a foundational heat transfer analysis model are imperative. In this study, a three-dimensional stacked module is modeled using FloTHERM finite element simulation technology, and its temperature profile is subsequently simulated. The thermal resistance value of the module's shell is calculated to be 37.25 °C W −1 . Subsequently, utilizing the instantaneous state dual interface method, the junction-to-case thermal resistance of the module is experimentally measured using T3ster equipment. Two identical modules are tested, revealing a junction-to-case resistance value of 39.45 °C W −1 for module No. 1 and 40.50 °C W −1 for module No. 2—both approximately 40 °C W −1 , thereby validating the accuracy and repeatability of the tests. A comparative analysis between the simulated and experimental thermal resistance values indicates an error of approximately − 5.5% for module 1 and − 8.0% for module 2. Further analysis suggests potential sources of error, such as thermal conductivity of the plastic packaging material and hot spot distribution. The paper concludes with simulation-based analyses of plastic packaging material thermal conductivity and hot spot distribution, offering insights for refining the simulation model. This study verifies the correctness of the results obtained by using finite element analysis to build a model for thermal simulation analysis. It has reference value for the thermal simulation analysis and thermal resistance test method of 3D integrated package module.

The contact thermal resistance between solid surfaces cannot achieve the observed contact area at the macroscopic scale; actual contact at the microscopic level only consists of discrete points or small areas, This paper investigates the coupled heat transfer between the refrigerator and heat pipe in a spacecraft refrigeration system. A disk computational model was established, and through thermal simulation calculations and vacuum test experiments, the contact heat transfer coefficients for dry contact, GD414 silicone rubber filler, thermal insulation pads, and thermal silicone grease were obtained. This model can be used to predict thermal coupling results in engineering applications and effectively guide engineering practices.

Laser powder bed fusion (LPBF) is a well-studied additive manufacturing (AM) process that is currently employed in most industries. LPBF manufactured parts tend to be larger, and trial errors are very costly when production fails. Simulation tools enable the anticipation of distortion issues from residual stress formation. These distortions and other defects generated during the LPBF process have thermal origins, and a thorough thermal history simulation is required before any mechanical or metallurgical simulations. The parameters influencing the thermal fields are applied at different spatial and temporal ranges, making it difficult to simulate the entire process with a unique finite element (FE) time-space mesh. The objective of the method presented in this study is to consider every identified parameter with an impact on the thermal field during the process. This approach is a sequential multiscale FE analysis from the macroscale to any specific microscale region. This approach is based on a specific definition of the temporal and spatial domains defined from the mentioned parameters. A case study was performed to highlight the method: progressive zooming was performed to estimate the thermal fields at five different scales, down to the microscale, that is, near a melt pool. Using this approach, specific regions were selected and zoomed down based on the peak temperatures. Simplifying hypotheses were methodically introduced, and both initial and boundary conditions were defined from the results of the previous levels. The computing durations for this specific part were approximately 14 h, and ways of improving the durations were discussed.

In this paper, the welding thermal cycle process of deep-sea pipeline steel was investigated by welding thermal simulation. The microstructure evolution, crystallology and second-phase precipitation behavior of the soft zone of the heat-affected zone (HAZ) were characterized and analyzed by combining scanning electron microscopy, electron back-scattered diffraction, transmission electron microscopy and hardness testing. The results show that HAZ softening appeared in the fine-grained zone with a peak temperature of 900–1000 °C for deep-sea pipeline steel, the base metal microstructure of which was the polygonal ferrite and acicular ferrite. Using V microalloying and low welding heat input could effectively decrease the softening of the HAZ fine-grained region, which was achieved by reducing the effective grain size, increasing the proportion of the dislocation substructures, and precipitating the nanoscale second-phase particles.

The effect of peak temperature (TP) on the microstructure and impact toughness of the welding heat-affected zone (HAZ) of Q690 high-strength bridge steel was studied using a Gleeble-3500 thermal simulation testing machine. The results show that the microstructure of the inter critical heat-affected zone (ICHAZ) was ferrite and bainite. The microstructure of fine grain heat-affected zone (FGHAZ) and coarse grain heat-affected zone (CGHAZ) was lath bainite (LB), lath martensite (LM), and granular bainite (GB), but the microstructure of FGHAZ was finer. With the increase in peak temperature, the content of LB and GB decreased, the content of LM increased, and the lath bundles of LM and LB gradually became coarser. With the increase in peak temperature, the grain size of the original austenite increased significantly, and the impact toughness decreased significantly. When the peak temperature was 800 °C, the toughness was the best. For CGHAZ, the peak temperature should be less than 1200 °C to avoid excessive growth of grain and reduction of mechanical property.

The material properties of thermoplastic polymer parts manufactured by the extrusion-based additive manufacturing process are highly dependent on the thermal history. Different numerical models have been proposed to simulate the thermal history of a 3D-printed part. However, they are limited due to limited geometric applicability; low accuracy; or high computational demand. Can the time–temperature history of a 3D-printed part be simulated by a computationally less demanding, fast numerical model without losing accuracy? This paper describes the numerical implementation of a simplified discrete-event simulation model that offers accuracy comparable to a finite element model but is faster by two orders of magnitude. Two polymer systems with distinct thermal properties were selected to highlight differences in the simulation of the orthotropic response and the temperature-dependent material properties. The time–temperature histories from the numerical model were compared to the time–temperature histories from a conventional finite element model and were found to match closely. The proposed highly parallel numerical model was approximately 300–500 times faster in simulating thermal history compared to the conventional finite element model. The model would enable designers to compare the effects of several printing parameters for specific 3D-printed parts and select the most suitable parameters for the part.

Vernacular architecture constitutes a rich source of information and ancestral knowledge and could become a key resource for sustainable development. Its passive design strategies effectively respond to local climatic and weather conditions, using locally sourced materials for the construction of its supporting structures and enveloping elements, as well as spatial organization and the incorporation of a buffer area (courtyard) that optimize the use of renewable resources. This qualitative study analyzes a traditional housing typology with a central courtyard located in the Historic Center of Azogues, Ecuador. In situ monitoring was conducted to evaluate the case study’s interior thermal comfort in different building spaces. Using the open-source software Open Studio and EnergyPlus, a simulation model was built to assess the annual thermal performance of the house. Field records were used to verify the effectiveness of the strategies that responded to the location’s climatic conditions. The analysis of the passive strategies used in the selected house included natural ventilation, solar protection, and thermal insulation, which depended on various aspects of the building, such as its location, the internal space’s arrangement, and the design of openings (doors and windows), among others. The thermal simulations revealed that the traditional house located in the Historic Center of Azogues was well adapted to the local climate, although the interior thermal comfort was not entirely satisfactory.

Silicon carbide (SiC) half-bridge power modules are widely utilized in new energy power generation, electric vehicles, and industrial power supplies. To address the research gap in collaborative validation between electro-thermal coupling models and process reliability, this paper proposes a closed-loop methodology of “design-simulation-process-validation”. This approach integrates in-depth electro-thermal simulation (LTspice XVII/COMSOL Multiphysics 6.3) with micro/nano-packaging processes (sintering/bonding). Firstly, a multifunctional double-pulse test board was designed for the dynamic characterization of SiC devices. LTspice simulations revealed the switching characteristics under an 800 V operating condition. Subsequently, a thermal simulation model was constructed in COMSOL to quantify the module junction temperature gradient (25 °C → 80 °C). Key process parameters affecting reliability were then quantified, including conductive adhesive sintering (S820-F680, 39.3 W/m·K), high-temperature baking at 175 °C, and aluminum wire bonding (15 mil wire diameter and 500 mW ultrasonic power/500 g bonding force). Finally, a double-pulse dynamic test platform was established to capture switching transient characteristics. Experimental results demonstrated the following: (1) The packaged module successfully passed the 800 V high-voltage validation. Measured drain current (4.62 A) exhibited an error of <0.65% compared to the simulated value (4.65 A). (2) The simulated junction temperature (80 °C) was significantly below the safety threshold (175 °C). (3) Microscopic examination using a Leica IVesta 3 microscope (55× magnification) confirmed the absence of voids at the sintering and bonding interfaces. (4) Frequency-dependent dynamic characterization revealed a 6 nH parasitic inductance via Ansys Q3D 2025 R1 simulation, with experimental validation at 8.3 nH through double-pulse testing. Thermal evaluations up to 200 kHz indicated 109 °C peak temperature (below 175 °C datasheet limit) and low switching losses. This work provides a critical process benchmark for the micro/nano-manufacturing of high-density SiC modules.

The development of precision machine tools requires an accurate understanding of the thermal behaviour of the tools. Therefore, by developing highly accurate machine tool thermal behaviour simulations, it can accurately forecast the functional performance of a machine tool at the prototype design stage and provide guidance on its design and performance optimization. To improve the accuracy of the thermal simulation of machine tools, it proposed whole-machine temperature field and thermal deformation modeling and a simulation method for vertical machining centers. Based on the studies of thermal–structure coupling finite-element data flow and its critical conditions, it also proposed design and computational methods for obtaining the heat-source power, when various rotational speeds, the forced convection heat transfer coefficient between a rotating surface and the air, the combined heat transfer coefficient between a stationary surface and the air/environment, and key contact surface thermal resistances were considered. Furthermore, this paper performed finite-element simulation analysis based on the constructed whole-machine thermal model, and the temperature characteristics and heat deformation mechanism/state were obtained. After comparing the simulation and experimental results, it verified the effectiveness of the finite-element simulation model and the relevant methods and confirmed that the simulation accuracy for both the temperature characteristics and the thermal deformation had been improved significantly, with a simulation error less than 10 %.

In order to explore the graphitization of inertinite, this paper conducted high-temperature thermal simulation experiments (HTT) and high-temperature high-pressure simulation experiments (HTHP) on isolated samples enriched in inertinite. X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) were used to analyze the graphitization process of inertinite. ① Results of HTT: the graphitization of inertinite has a “threshold condition” with the temperature threshold ranging between 2100 °C and 2400 °C. Below this threshold, the d002 value of the samples remains above 0.342 nm. ② Results of HTHP: (i) External forces have a significant positive effect on the graphitization of inertinite. Compared to the HTT, the addition of external forces significantly reduces the temperature required for inertinite graphitization. (ii) Proper combinations of temperature and pressure conditions are crucial for efficiently promoting the graphitization of inertinite. Changes in pressure, either increasing or decreasing from the optimal pressure, have a suppressive effect on the graphitization of inertinite. ③ The mechanism of external forces on the graphitization of inertinite was analyzed. Shear stress promotes the rotation and orientation of aromatic layers, while static hydrostatic pressure contributes to the contraction and reduction of interlayer spacing in carbon layers.