Article
Engineering, Industrial
Min Zheng, Geng Wang, Weitian Zhou, Lei Wei, Xin Lin, Weidong Huang
Summary: In this study, a real-time coupled simulation model was constructed to investigate the effect of energy input on the grain structure of laser powder bed fusion (L-PBF) fabricated parts. The simulation results showed that energy input significantly influenced the type, distribution, and size of grains, and that grain morphology depended on the location and shape of the fusion boundary. Additionally, comparing the 3D morphology with the 2D cross-section morphology of grains revealed potential biases in 2D experimental observations. The findings of this study are important for guiding process parameters for site-specific microstructure of L-PBF fabricated parts.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Noah M. Kohlhorst, Kevin M. Faraone, Roger G. Miller, Govindarajan Muralidharan, George B. Ulrich, Ji-Cheng Zhao
Summary: The choice of weld parameters affects the microstructure of the fusion zone and heat-affected zone, which in turn influences the mechanical properties of welds. A new technique was used to evaluate and analyze the microstructural characteristics in both zones of molybdenum gas tungsten arc welds fabricated with different weld parameters. The study found correlations between microstructural characteristics and heat input, weld speed, and weld technique.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Daniel Dreelan, Alojz Ivankovic, David J. Browne
Summary: This study reports the development of a Cellular Automata (CA) model for grain nucleation and growth that can simulate columnar and equiaxed solidification. The new model is validated by comparing its predictions to those of the existing Front Tracking (FT) model. The study provides insights into the thermophysical phenomena affecting grain structure evolution and confirms the utility of an equiaxed index.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Computer Science, Interdisciplinary Applications
Adrian S. Sabau, Lang Yuan, Jean-Luc Fattebert, John A. Turner
Summary: This paper investigates performance strategies for a cellular automata (CA) simulation code on GPU-based HPC platforms, focusing on non-equilibrium solidification processes in metal additive manufacturing (AM). The results demonstrate that using a precomputed list of interface cells greatly reduces the wall-clock time on GPUs, and the GPU-accelerated code exhibits excellent weak scaling performance.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Thermodynamics
Fengye Tang, Kai Guo, Xiangbo Liu, Yanhong Wei, Jicheng Chen
Summary: This paper investigates the mechanism and behavior of pulsed laser welding process in connecting metal plates through numerical simulations and experimental studies. The results indicate that by controlling the shape of the weld pool and optimizing the energy absorption, good welding results can be achieved.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Metallurgy & Metallurgical Engineering
Jiajie Wang, Wenjian Zheng, Juhao Yu, Jianping Xu
Summary: The study investigates the morphology evolutions of the sidebranch during the solidification of weld pool under transient conditions using experiments and a quantitative phase field method. It is found that the sidebranching spacings formed in transient growth of the weld pool are larger than that under steady-state conditions. The reasons behind this phenomenon are discussed through noise amplification theory and time-dependent linear stability analyses.
WELDING IN THE WORLD
(2021)
Article
Metallurgy & Metallurgical Engineering
Takanori Ito, Osamu Ozaki, Tomohiro Nishimura, Hiroshi Hashimoto, Hidenori Nako, Keito Ishizaki
Summary: Liquefied natural gas (LNG) has gained attention worldwide due to environmental concerns. This study investigates the use of electromagnetic stirring (EMS) to improve the microstructure and reduce inclusion density in 12%Ni steel weld metals for electroslag welding (ESW).
WELDING IN THE WORLD
(2023)
Article
Materials Science, Multidisciplinary
Ashish Arote, Junji Shinjo, D. Graham McCartney, Roger C. Reed
Summary: To accurately simulate the free dendritic growth problem, a computationally efficient, accurate, and elegant cell capturing method termed limited circular neighbourhood (LCN) is proposed. The LCN method is able to reduce artificial grid anisotropy and capture growth orientation accurately, resulting in reduced mass loss and shape error compared to other methods. It is also demonstrated that the LCN method is effective for both free dendrite growth in a pure material and constrained dendritic growth in a binary alloy with multiple growth sites.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Sindo Kou
Summary: The study demonstrated that a specific index can serve as a crack-susceptibility indicator for straight columnar dendritic grains growing side by side, whether using an elliptical weld pool or a teardrop-shaped pool in welding processes.
SCIENCE AND TECHNOLOGY OF WELDING AND JOINING
(2021)
Article
Materials Science, Multidisciplinary
Rongyi Zhou, Xiaohui Feng, Ce Zheng, Qiuyan Huang, Yingju Li, Yuansheng Yang
Summary: The effects of drawing velocity, initial grain size and texture on the microstructure evolution during directional annealing were investigated using a cellular automata model based on grain boundary (GB) curvature, GB energy and GB mobility with a modified calculation model of the GB curvature. The simulation results showed that there were lower and upper limits to the drawing velocity for the formation of columnar grains, and the columnar grains could only be formed within this range. The simulation results were consistent with experimental results. Additionally, the growth of equiaxed grains hindered the formation of columnar grains when the drawing velocity was below the lower limit, and the driving force of GB migration decreased with increasing initial grain size, making it difficult for the grain boundaries to move with the hot zone, thus inhibiting the formation of columnar grains. The abnormal growth induced by texture also prevented the growth of columnar grains during directional annealing, with weaker texture strength being more conducive to the growth of columnar grains.
Article
Engineering, Manufacturing
Yukai Chen, Yin Wang, Hao Li, Yu Lu, Bin Han, Qi Zhang
Summary: This study presents a multi-scale simulation study of grain growth in the L-PBF process of Inconel 718 material. The simulation results were consistent with experimental results, and the effects of process parameters on microstructure were analyzed. The study provides important insights into the grain growth and development in the L-PBF process.
VIRTUAL AND PHYSICAL PROTOTYPING
(2023)
Article
Metallurgy & Metallurgical Engineering
Ling Shi, Songzhe Xu, Heyu Lu, Chaoyue Chen, Sansan Shuai, Tao Hu, Andrew Kao, Jiang Wang, Zhongming Ren
Summary: In this work, a novel high-efficiency virtual submesh cellular automata (VISCA) method is proposed to reduce artificial anisotropy caused by the mesh. The VISCA method significantly reduces computational cost and improves computational efficiency compared to previous CA models. It achieves good accuracy in microstructure simulation during solidification.
ISIJ INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Dmitrii Ushmaev, Zhirong Liao, Andy Notron, Dragos Axinte
Summary: This paper investigates the solidification phenomena and mechanisms of laser-melted YSZ and identifies two coexisting solidification behaviors. It proposes a new cellular automata approach to explain the formation mechanisms of these phenomena and demonstrates its accuracy and efficiency in predicting grain microstructure in laser processing.
MATERIALS & DESIGN
(2022)
Article
Physics, Mathematical
Michael Freedman, Jeongwan Haah, Matthew B. Hastings
Summary: This research considers the group structure of quantum cellular automata (QCA) modulo circuits and shows that it is abelian even without the assumption of ancillas in most reasonable choices of control space. Furthermore, it demonstrates how to define a well-defined QCA group without the need for using families, by constructing a coherent family containing arbitrary finite QCAs. The construction also applies to translation invariant QCA and shows that all translation invariant QCA in three dimensions and all translation invariant Clifford QCA in any dimension are coherent.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Chemistry, Physical
Andrey Malakhov, Alexander Epishin, Igor Denisov, Ivan Saikov, Gert Nolze
Summary: This study analyzed the morphology and structure of the weld interface in a brass-Invar bimetal and found that the interface exhibits a typical wavy structure with melted zones and undissolved Invar particles. The distribution of crystallographic orientation of grains was also observed, along with deformation twins, dislocation accumulations, and shear bands.
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)