Article
Engineering, Mechanical
Xianfei Liu, Hao Jiang, Fang Wang, Guodong Xia, Hui Zhang, Zhiqiang Li, Caixia Zhu, Zirui Zhang, Yuhang Liu, Doudou Zhao
Summary: This study aims to investigate the flow behavior and oil film thickness in the vertical helical channel to enhance the efficient operation of the single screw expander. It was found that the liquid film thickness improves with downward flow, and becomes more symmetrical with increasing oil viscosity, surface tension, and other factors.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Thermodynamics
Xinghua Wei, Rijing Zhao, Siyuan Wu, Shouzhen Wang, Dong Huang
Summary: This study proposed a novel falling film flow absorber, which is composed of the microchannel flat tube and rhombus mesh. The effect of rhombus mesh on falling film flow characteristics over microchannel flat tube absorber was studied numerically and experimentally. The results showed that the rhombus mesh improved the coverage ratio of the liquid film and enhanced internal mixing.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Wei Wang, Han Qiao, Biao Lei, Yu-ting Wu, Chong-fang Ma
Summary: The pressure losses in the inlet and exhaust passages have a significant impact on the performance of SSEs. Enhancing the pressure drop effect of leakage and reducing the flow resistance loss of inlet and exhaust passages simultaneously through structural optimization is crucial for improving the expansion ratio. Additionally, the flow losses of inlet and exhaust passages can significantly influence the performance of SSEs.
Article
Engineering, Chemical
Jie Zeng, Yifei Wang, Tingting Li, Zongren Pan, Zhenghua Dai, Guangsuo Yu
Summary: The effect of wall distortion on the turbulent falling film is significant. Using corrugated plates to simplify the wall distortion, this study investigated the influence of structural parameters on the action mechanism of solitary waves and the axial distribution of liquid film thickness. The results reveal that the Coanda effect alters the flowing liquid film attached to the wall, resulting in the generation and extinction of solitary waves. Additionally, the local perturbation easily promotes the formation of slender water columns and subsequent breakup into tiny droplets under Plateau-Rayleigh instability. The mean liquid film thickness prediction model accurately predicts the film thickness on corrugated plates with relative errors within +/- 15%.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Spectroscopy
Zhiyuan Liu, Hao Sun, Wei Huang, Kun Wang, Mingxu Su, Huinan Yang
Summary: In the simultaneous measurement of liquid film temperature and thickness based on multi-wavelength absorption spectroscopy, optimal wavelength combinations were selected to improve measurement accuracy. The absorption spectra of e-liquid at different temperatures were measured, and ten sets of two-wavelength and three-wavelength combinations were established. The accuracy of all combinations was validated and an optimal three-wavelength combination was selected. This combination achieved high accuracy in the simultaneous measurement of liquid film temperature and thickness.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Thermodynamics
R. Clavenna, L. Araneo
Summary: The study proposes a novel non-intrusive infrared technique called Twin Background Subtraction (TBS) to simultaneously measure the thickness and temperature of a semi-transparent thin film. The technique utilizes the mid-wave IR emission from the film and the radiation attenuation by the same film of the emission from two backgrounds at different temperatures. The study discusses the theoretical and experimental aspects of the TBS method and its dependence on different parameters and fluid properties.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2023)
Article
Thermodynamics
Xinfeng Zhai, Cong Qi, Yuqi Yang, Jiangyun Wang
Summary: The study investigates the effects of an adjustable magnetic field on the convective heat transfer performance and flow resistance coefficient of water-based Fe3O4 nanofluids under different Reynolds numbers. It was found that the convective heat transfer performance is directly related to the mass fraction, magnetic field strength, and pitch curvature ratio, with an increase in heat transfer efficiency observed with the use of ferrofluid and higher magnetic field strengths. Additionally, different pitch curvature ratios of spiral tubes also affect heat transfer performance.
APPLIED THERMAL ENGINEERING
(2021)
Article
Mechanics
Yi Zheng, Shuai Yang, Xiangdi Zhao, Zheng Wang, Jiwu Yuan, Xuehu Ma
Summary: The behavior of falling film over horizontal tube evaporators and absorbers has significant impacts on heat and mass transfer efficiency, especially for intermittent droplet model at low spray density. The study found that droplet generation and growth stages accounted for more than half of the droplet life cycle, and observed obvious droplet retraction and pulsation during droplet generation. The film thickness transient evolution regulation of droplet mode could be split into impact zone and stable zone, with rapid decrease in film thickness in impact zone and stable film thickness in stable zone until the next droplet impact.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2021)
Article
Thermodynamics
Gautier Rouaze, Jackson B. Marcinichen, Filippo Cataldo, Philippe Aubin, John R. Thome
Summary: JJ Cooling Innovation has significantly improved their one-dimensional transient numerical code to accurately simulate the thermal/hydraulic performance of pulsating heat pipes. Through a mechanistic approach, the code predicts the working conditions of the PHP by solving all variables, including liquid film thickness and the formation of new vapor plugs.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Tsutomu Ubara, Katsumi Sugimoto, Hitoshi Asano
Summary: This study experimentally investigated the liquid film thickness and heat transfer coefficients on an inclined plate and found that the film thickness increases under nucleate boiling conditions, and the average thickness increases with the heat flux.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Gaurav Prakash Srivastava, Anil Kumar Patil, Manoj Kumar
Summary: This study examines the flow and thermal characteristics of a tube with perforated conical inserts by varying the Reynolds number. It is found that solid inserts with lower pitch to diameter ratio are suitable for high energy transfer at lower Reynolds numbers, while perforated conical inserts are effective at higher Reynolds numbers. Empirical correlations are developed for both solid and perforated conical inserts.
EXPERIMENTAL HEAT TRANSFER
(2022)
Article
Thermodynamics
Yanhong Sun, Wenjie Chen, Jinli Lu, Changlong Wang
Summary: In this study, experimental investigation on the flow and heat transfer characteristics of a thin liquid film in micro circular tubes with an inner diameter of 0.5 mm was conducted. The results showed that the temperature and pressure fluctuation was consistent with the generation of bubble clusters, providing insights into the mechanism of flow boiling instability. The characteristics of void fraction, such as the duration of bubbles and liquid slugs, were obtained from the dynamic distribution diagram of the liquid film thickness, and the experimental data showed a good agreement with the homogeneous model. The temporary variation of the thin liquid film offered an opportunity to probe the physics of bubble dynamics and instability during flow boiling.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Engineering, Mechanical
Mao Ueda, Janet S. S. Wong, Hugh Spikes
Summary: This paper investigates the influence of appropriate blends of PAOs and PIBs on micropitting. The findings show that these blends can provide thick oil film thicknesses and reduce micropitting while maintaining low viscosity.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Ton Lubrecht, Nans Biboulet, Kees Venner
Summary: The paper summarizes the contributions of Dowson, Higginson, and Hamrock to numerical line contact elastohydrodynamic lubrication and film thickness prediction in elliptical contacts, finding that the predicted results are accurate, especially under pure rolling conditions.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Thermodynamics
Xiaoya Li, Steven Lecompte, Jera Van Nieuwenhuyse, Kenny Couvreur, Hua Tian, Gequn Shu, Michel De Paepe, Christos N. Markides
Summary: The study introduced the potential of liquid-flooded expansion technology in enhancing the performance of the basic ORC, with experiments showing improved expander power output and isothermal efficiency. Increasing the amount of liquid flooding can further enhance the power output and thermal efficiency of the system, suggesting the potential for performance improvement by modifying the cycle thermodynamics itself.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Engineering, Mechanical
Xianfei Liu, Hao Jiang, Fang Wang, Guodong Xia, Hui Zhang, Zhiqiang Li, Caixia Zhu, Zirui Zhang, Yuhang Liu, Doudou Zhao
Summary: This study aims to investigate the flow behavior and oil film thickness in the vertical helical channel to enhance the efficient operation of the single screw expander. It was found that the liquid film thickness improves with downward flow, and becomes more symmetrical with increasing oil viscosity, surface tension, and other factors.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Thermodynamics
Xianfei Liu, Hui Zhang, Fang Wang, Caixia Zhu, Zhiqiang Li, Doudou Zhao, Hao Jiang, Yuhang Liu, Zirui Zhang
Summary: The study proposes an innovative wavy microchannel heat sink with fan-shaped ribs, and validates its advantage in improving thermal performance by considering thermo-physical properties. New insights into flow and heat transfer mechanisms are obtained. The study also finds that the geometric parameters of the ribs significantly affect the thermal performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Green & Sustainable Science & Technology
Xianfei Liu, Hui Zhang, Fang Wang, Caixia Zhu, Zhiqiang Li, Zirui Zhang, Hao Jiang, Doudou Zhao, Yuhang Liu
Summary: This study explores the role of phase change material (PCM) in improving the thermal management performance of the fast charging module. A comparative analysis of the thermal management system performance with and without the PCM is performed, and some conclusions are drawn.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Thermodynamics
Xianfei Liu, Zirui Zhang, Caixia Zhu, Fang Wang, Doudou Zhao, Zhiqiang Li, Yuhang Liu, Hui Zhang, Hao Jiang
Summary: This experimental research shows that adding paraffin wax as an appropriate organic phase change material (PCM) has advantageous effects on controlling the temperature rise of a fast charging power module (100 mm x 50 mm x 20 mm). The study examines the impact of PCM physical parameters on thermal management performance and visualizes the PCM melting process to reveal the mechanism behind its improvement. The results demonstrate a temperature reduction of 46.4 degrees C with PCM coupling, and increasing air flow velocity decreases the temperature by 11.8 degrees C. Increasing PCM thermal conductivity from 0.2 W/(m center dot K) to 5 W/(m center dot K) in 1800 s lowers the extreme temperature from 60.1 degrees C to 51.9 degrees C. Filling PCM with a thickness of 4.5 mm outperforms other thicknesses in thermal management performance. These findings offer reliable technical solutions for improving the thermal management of charging piles and high-power quick charging piles.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Xianfei Liu, Zirui Zhang, Hui Zhang, Fang Wang, Doudou Zhao, Zhiqiang Li, Caixia Zhu, Yuhang Liu, Hao Jiang
Summary: The benefits of adding phase change material (PCM) to the thermal control system of high-power fast charging power module are explored. The study investigates the effects of PCM's melting temperature, thermal conductivity, and filling thickness on the improvement of charging time, as well as visualizes the PCM melting rate. Results show that PCM significantly extends charging time, with the optimal melting temperature at 47.5 degrees C and a maximum charging time of 1540 s. PCM thickness and thermal conductivity also play crucial roles in extending charging time.
JOURNAL OF CLEANER PRODUCTION
(2023)
Review
Energy & Fuels
Fang Wang, Dongqing Pang, Xianfei Liu, Mengwei Liu, Weifeng Du, Yichi Zhang, Xiaoqian Cheng
Summary: Exposure to high temperature and humidity in summer can cause heat stroke or even death due to an imbalance in the body's heat-regulation function. Phase-change materials, which have a small volume and large capacity for absorbing latent heat, are often used in clothing to reduce the temperature and humidity of the clothing microenvironment and improve thermal comfort. This review summarizes the factors to consider in selecting phase-change materials for cooling clothing, including the phase-change temperature, form, and composition. It also discusses the effects of melting temperature, heat storage, thermal conductivity, dosage, and location of phase-change materials on the heat-dissipation performance of cooling clothing. Additionally, the review summarizes methods for using phase-change materials to reduce temperature and humidity inside clothing and explores research directions for improving the lifetime of phase-change materials and developing portable personal equipment with cooling and dehumidification functions.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Thermodynamics
Zhongfei Liu, Yang Ding, Fang Wang, Shumin Ding, Shiyuan Wang, Zhenzhen Zhang, Yunding Li, Wenliang Guo
Summary: This paper focuses on the research of heat transfer in cryogenic fluid in spiral coil during the extraction and usage of liquefied natural gas (LNG) cold energy. Computational fluid dynamics numerical analysis is conducted on a non-customized numerical model with variable physical parameters and the Realizable k-epsilon turbulence model. The results show that heat transfer under non-constant boundary conditions is more accurate and the spiral radius has the greatest influence on the heat transfer coefficient, decreasing by 60.14% when the spiral radius increases from 40 to 100 mm.
INTERNATIONAL JOURNAL OF LOW-CARBON TECHNOLOGIES
(2023)
Article
Energy & Fuels
Xianfei Liu, Zirui Zhang, Fang Wang, Hui Zhang, Zhiqiang Li, Caixia Zhu, Doudou Zhao, Yuhang Liu, Hao Jiang
Summary: Fast charging technologies pose challenges for efficient heat management in charging modules. A transient thermal analysis model is used to evaluate a novel thermal management system for high power fast charging piles. Results show that adding phase change materials (PCM) limits the system's performance under larger air convective coefficients and higher ambient temperatures, but has a beneficial effect on various liquid convective coefficients and heat generation powers.
Article
Thermodynamics
Fang Wang, Mengchu Li, Yanling Zhang, Xianfei Liu, Dong Xie, Qiongwei Zhang, Huiling Yang
Summary: A roof-mounted radiant cooling system with a bypass structure was designed for LNG-fueled refrigerated vehicles, providing stable dynamic regulation. The system's cooling capacity exceeds 1.2 kW at economical speeds, meeting the requirements for refrigerated vehicles. The dynamic regulation strategy developed in this study allows for use of the refrigerated vehicle under various climactic conditions and improves cooling system stability.
INTERNATIONAL JOURNAL OF LOW-CARBON TECHNOLOGIES
(2021)
Article
Engineering, Mechanical
Rosaria Del Toro, Maria Laura De Bellis, Marcello Vasta, Andrea Bacigalupo
Summary: This article presents a multifield asymptotic homogenization scheme for analyzing Bloch wave propagation in non-standard thermoelastic periodic materials. The proposed method derives microscale field equations, solves recursive differential problems within the unit cell, establishes a down-scaling relation, and obtains average field equations. The effectiveness of this approach is validated by comparing dispersion curves with those from the Floquet-Bloch theory.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Yue Bao, Zhengcheng Yao, Yue Zhang, Xueman Hu, Xiandong Liu, Yingchun Shan, Tian He
Summary: This paper proposes a novel triple-gradient phononic acoustic black hole (ABH) beam that strategically manipulates multiple gradients to enhance its performance. The study reveals that the ABH effect is not solely brought about by the thickness gradient, but also extends to the power-law gradients in density and modulus. The synergistic development of three different gradient effects leads to more pronounced and broader bandgaps in PCs.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Matthias Ryser, Jason Steffen, Bekim Berisha, Markus Bambach
Summary: This study investigates the feasibility of replacing complex experiments with multiple simpler ones to determine the anisotropic yielding behavior of sheet metal. The results show that parameter identifiability and accuracy can be achieved by combining multiple specimen geometries and orientations, enhancing the understanding of the yield behavior.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Wenjun Li, Pengfei Zhang, Siyong Yang, Shenling Cai, Kai Feng
Summary: This study presents a novel two-dimensional non-contact platform based on Near-field Acoustic Levitation (NFAL), which can realize both one-dimensional and two-dimensional transportation. Numerical and experimental results prove the feasibility and ease of this method.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Shuo Liu, Lu Che, Guodong Fang, Jun Liang
Summary: This study presents a novel lamina conjugated bond-based peridynamic (BB-PD) model that overcomes the limitations of material properties and is applicable to composite laminates with different stacking sequences. The accuracy and applicability of the model are validated through simulations of elastic deformation and progressive damage behavior, providing an explanation of the damage modes and failure mechanisms of laminated composite materials subjected to uniaxial loading.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Omar El-Khatib, S. Kumar, Wesley J. Cantwell, Andreas Schiffer
Summary: Sandwich-structured honeycombs (SSHCs) are hierarchical structures with enhanced mass-specific properties. A model capable of predicting the elastic properties of hexagonal SSHCs is presented, showing superior in-plane elastic and shear moduli compared to traditional honeycombs, while the out-of-plane shear moduli are reduced.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Zhi-Jian Li, Hong-Liang Dai, Yuan Yao, Jing-Ling Liu
Summary: This paper proposes a process-performance prediction model for estimating the yield strength and ultimate tensile strength of metallic parts fabricated by powder bed fusion additive manufacturing. The effect of main process variables on the mechanical performance of printed metallic parts is analyzed and the results can serve as a guideline for improvement. The accuracy of the proposed model is validated by comparison with literature.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Saman A. Bapir, Kawa M. A. Manmi, Rostam K. Saeed, Abdolrahman Dadvand
Summary: This study numerically investigates the behavior of an ultrasonically driven gas bubble between two parallel rigid circular walls with a cylindrical micro-indentation in one wall. The primary objective is to determine the conditions that facilitate the removal of particulate contamination from the indentation using the bubble jet. The study found that the bubble jet can effectively remove contamination from the indentation for certain ranges of indentation diameter, but becomes less effective for larger indentation diameters.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
E. Polyzos, E. Vereroudakis, S. Malefaki, D. Vlassopoulos, D. Van Hemelrijck, L. Pyl
Summary: This research investigates the elastic and damage characteristics of individual composite beads used in 3D printed composites. A new analytical probabilistic progressive damage model (PPDM) is introduced to capture the elastic and damage attributes of these beads. Experimental results show strong agreement with the model in terms of elastic behavior and ultimate strength and strain.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
