Article
Thermodynamics
Huang Guangwen, Liu Wangyu, Luo Yuanqiang, Li Yong, Chen Hanyin
Summary: With the rapid development of high-performance portable electronics, heat pipes need higher heat transfer capacity to meet the heat dissipation needs. A novel composite wick structure can increase wick permeability, delay evaporation end drying out, and improve capillary performance of wicks through thermal oxidation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Feng Yi, Yunhua Gan, Zhifeng Xin, Yong Li, Hanyin Chen
Summary: This study explores the thermal characteristics of two different porous media, SWM and SCP, in different length proportions, particle sizes of SCP, and heating directions to enhance the thermal performance of UTHP. It is found that SCP and SWM perform differently when compounded with different proportions. Although the best performance is observed when the length proportion of SCP is 50%, the composite structure is not always superior to the single-wick structure. With appropriate parameters, UTHP with a segmented wick shows higher maximum heat dissipation capacity and lower thermal resistance compared to UTHP with a single wick structure.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Maroosol Yun, Wei-Ting Hsu, Dong Il Shim, Juyeong Nam, Jae Hun Heo, Jung-Youn Song, Kyu Tae Park, Dong Hyun Lee, Hyung Hee Cho
Summary: With the advancement in chip integration, capillary heat pipes are becoming increasingly important for thermal management of high-heat-flux electronic devices. By utilizing a thermal circuit model and 3D printing, it is possible to design and fabricate heat pipes with desired heat transfer performance.
APPLIED THERMAL ENGINEERING
(2024)
Review
Chemistry, Physical
Pawel Szymanski, Dariusz Mikielewicz, Sasan Fooladpanjeh
Summary: This article summarizes the advancements in the design and fabrication of wick structures in loop heat pipes (LHPs) and highlights the potential of composites and additively manufactured wicks in improving the heat transfer coefficient.
Article
Thermodynamics
Xianfeng Hu, Chengzhi Hu, Yichuan He, Haochen Xu, Dawei Tang
Summary: Loop heat pipe (LHP) is a promising heat dissipation technology for electronic devices, and the optimized design of porous wick is crucial for improving its heat transfer capacity. In this study, a polymer material-polyethersulfone (PES) film was chosen as the porous wick due to its unique dual pore size structure. Experimental investigation showed that the PES wick outperformed copper mesh and sintered nickel powder wicks in terms of heat transfer capacity. The PES wick also showed advantages of light weight, simple preparation, and low cost, making it a promising choice for LHP applications.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Menglei Wang, Yifan Liu, Tomio Okawa
Summary: To enhance the usability of heat pipes and vapor chambers, a thin wick made of silica nanoparticles was used experimentally. Compared to ordinary heat pipes with wire mesh wicks, the thermal resistance was improved and the maximum heat transfer rate was not significantly affected. This study demonstrates that the nanoparticle layer can be used as a thin wick for heat pipes and vapor chambers.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Jing Zhang, Li-xian Lian, Ying Liu, Ren-quan Wang
Summary: In this study, the capillary limit of heat pipes was predicted based on capillary rise test, showing that irregular powders outperform spherical powders but the experimental values were approximately 7 to 11W higher than the predicted values. The experimental capillary limit was used to adjust the prediction equation at different working temperatures.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Miao Liu, Wenjing Ning, Junbo Yang, Yuankun Zhang, Zhuosheng Han, Ge Meng, Chunsheng Guo, Han Lin, Baohua Jia
Summary: This study proposes a novel composite pore former comprising NaCl and g-C3N4 for fabricating high-performance multi-morphology porous wicks. The synergistic effect of these pores increases the wicks' porosity and reduces flow resistance, enabling them to exhibit high comprehensive performance. The wicks also have ultralow thermal resistance and exceptional anti-gravity performance.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Multidisciplinary Sciences
Chao Chang, Zhaoyang Han, Xiaoyu He, Zongyu Wang, Yulong Ji
Summary: With the advancement of electronic technology, thermal management has become a major challenge for electronic device applications. A novel aluminum flat heat pipe, designed and fabricated using 3D printing technology, showed enhanced performance and efficiency with micro-grooves and high thermal conductivity. Research on working fluid filling ratio indicated that a 10% filling ratio provided the best heat transfer performance.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Menghao Wang, Yinchuang Yang, Yiwei Sun, Jian Li, Menglong Hao
Summary: This study proposes concentrated striped composite wick (CSCW) structures for ultra-thin flat heat pipes (UTFHPs) and evaluates their thermal performance experimentally. The results show that CSCW with a hollow structure in the evaporation section performs the best, and the passage width of the copper foam significantly affects the thermal performance. The UTFHP with the optimal wick structure exhibits the lowest thermal resistance and a higher effective thermal conductivity.
Article
Thermodynamics
Shwin-Chung Wong, Mao-Shen Deng, Min-Chieh Liu
Summary: This study investigates the capillary properties of a flat-plate heat pipe with a sintered composite copper mesh-groove wick and proposes a new formula for calculating its permeability. The experimental results show that the composite mesh-groove wick has a higher maximum heat load compared to another commonly used wick.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Nuclear Science & Technology
Joseph Seo, Daegeun Kim, Hansol Kim, Yassin A. Hassan
Summary: An experimental investigation on the hydraulic characteristics of annular type wick structures for heat pipes was conducted. A measurement facility was established to measure the porosity, permeability, and effective pore radius of the wick structures in vacuum conditions. The study found that a wick structure composed of specific mesh sizes had the highest permeability to effective pore radius ratio. The effect of the wick-to-wall gap on the hydraulic characteristics was also investigated, and it was determined that there is an optimal gap distance for the selected composite mesh structure.
NUCLEAR ENGINEERING AND DESIGN
(2022)
Article
Metallurgy & Metallurgical Engineering
Saif Ullah Khalid, Hafiz Muhammad Ali, Muhammad Ali Nasir, Riffat Asim Pasha, Zafar Said, L. Syam Sundar, Ahmed Kadhim Hussein
Summary: Heat pipes are widely used for thermal management, and comparing the performance of sintered copper wick and grooved heat pipes shows significant differences in capillary pressure, operating temperature, and thermal resistance, with grooved heat pipes reaching equilibrium faster.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Thermodynamics
Zhengang Zhao, Guohong Peng, Yanhui Zhang, Dacheng Zhang
Summary: In this paper, a novel sintered multi-size copper powder wick is designed and experimentally investigated for heat flux management. The results show that the new wick has shorter liquid transfer time, faster dynamic response time, and lower overall thermal resistance compared to single-size copper powder wicks.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Chemistry, Physical
Im-Nam Jang, Yong-Sik Ahn
Summary: The porosity, permeability, and capillary force of porous sintered copper were studied in relation to copper powder size, pore-forming agent, and sintering conditions. Higher values of porosity and permeability were observed when the copper powder size was uniform or small. The capillary force increased with the addition of more forming agent and was higher with larger and non-uniform copper powder size. The results were discussed in relation to porosity and pore size distribution.
Article
Thermodynamics
Liang Chen, Daxiang Deng, Qingsong Huang, Xinhai Xu, Yingxi Xie
APPLIED THERMAL ENGINEERING
(2020)
Article
Automation & Control Systems
Yanlin Xie, Daxiang Deng, Guang Pi, Xiang Huang, Chenyang Zhao
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2020)
Article
Automation & Control Systems
Liang Chen, Daxiang Deng, Guang Pi, Xiang Huang, Wei Zhou
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2020)
Article
Multidisciplinary Sciences
Xiang Huang, Wei Zhou, Daxiang Deng
SCIENTIFIC REPORTS
(2020)
Article
Energy & Fuels
Yuhua Wu, Jianpeng Cui, Xinhai Xu, Daxiang Deng
Summary: Concentrated photovoltaic (CPV) has attracted attention for its higher efficiency compared to traditional solar cells by concentrating sunrays. Heat dissipation is a critical challenge for CPV at high concentration ratios, but can be mitigated by adjusting water flow rate and temperature to reduce cell temperature and enhance power output. The overall efficiency of heat sinks is influenced by cooling area and channel numbers.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Thermodynamics
Daxiang Deng, Long Zeng, Wei Sun, Guang Pi, Yue Yang
Summary: A new type of open-ring pin fin microchannels (ORPFM) was proposed for advanced microchannel heat sinks, with inline arrangement showing improved boiling heat transfer, reduced pressure drop, and more stable flow boiling process at high heat fluxes through experimental investigation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Chemistry, Physical
Xiang Huang, Wei Zhou, Daxiang Deng
Summary: Understanding the correlation between pore-scale structure and diffusion transport property is crucial for designing and optimizing the performance of porous fibrous materials for energy applications. The lattice Boltzmann method (LBM) and pore network modeling (PNM) are commonly used modeling techniques, but direct comparisons between them have received little attention. Through simulations, it was found that the effective diffusion coefficients between the two methods were in good agreement when estimating throat radius using the cross-section area equivalent radius.
Article
Materials Science, Multidisciplinary
Daxiang Deng, Jian Zheng, Xiaolong Chen, Wei Sun
Summary: This study developed a facile and scalable thermal oxidation method to prepare CuO nanowires on the electrodischarge machining (EDM) processed V-shaped microgrooves. The formation of nanowires was influenced by both annealing temperature and time, and all the nanowire samples showed hydrophobic properties.
CURRENT APPLIED PHYSICS
(2021)
Review
Thermodynamics
Daxiang Deng, Long Zeng, Wei Sun
Summary: This paper comprehensively reviews recent advancements in flow boiling enhancement and fabrication of enhanced microchannels. It emphasizes the flow boiling enhancement performance of these enhanced microchannels in microchannel heat sinks, while also discussing their advantages and disadvantages after summarizing the classification and manufacturing methods of enhanced microchannels.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Mechanical
Long Zeng, Daxiang Deng, Ningbo Zhong, Guisen Zheng
Summary: A unique microchannel heat sink design with inline and staggered open-ring pin fins was developed for high heat flux devices. The open-ring pin fins induced flow separations and convergences, leading to enhanced heat transfer performance. The staggered configuration showed slightly better heat transfer performance than the inline configuration, making it more favorable for heat dissipation in high heat flux devices.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Thermodynamics
Zhi-Jia Xu, Man-Si Luo, Qing-Hui Wang, Hao Zhao, Ying-Jun Wang, Da-Xiang Deng
Summary: This paper proposes a shape optimization method to optimize the shape of the evaporator wick in CPVC, based on the study on the minimization of the maximum pressure drop. By analyzing sensitivity information, the side shape of the wick block is changed, reducing the maximum pressure drop and providing a more scientific and objective alternative for the design of wicks in CPVC.
APPLIED THERMAL ENGINEERING
(2022)
Article
Chemistry, Physical
Xiang Huang, Wei Zhou, Daxiang Deng, Bin Liu, Kaiyong Jiang
Summary: A stochastic pore network modeling method with tailored structures was proposed to investigate the impacts of surface microchannels on the transport properties of porous fibrous media. Results showed that microchannels increased permeability of flow while smaller pores provided higher resistance for better catalyst support. This work suggests that the modeling framework is promising for the design optimization of cross-scale porous structures.
Article
Engineering, Manufacturing
Da-Xiang Deng, Jian Zheng, Xiao-Long Chen, Guang Pi, Yong-Heng Liu
Summary: A laser-micromilling process was developed to fabricate micro pin fins on inclined V-shaped microchannel walls for enhanced heat sinks. The height of the pin fins increased with scanning speed but decreased with line spacing. Optimal processing parameters were found to be a laser output power of 21 W, scanning speed of 100-300 mm/s, and line spacing of 2-5 μm.
ADVANCES IN MANUFACTURING
(2022)
Article
Energy & Fuels
Liang Chen, Daxiang Deng, Qixian Ma, Yingxue Yao, Xinhai Xu
Summary: Efficient cooling is crucial for high concentration photovoltaic (HCPV) cells to maintain their electrical performance and extend their lifetime. In this study, a novel microchannel heat sink with serpentine reentrant microchannels (SRM) was developed for efficient cooling of HCPV cells. The SRM design effectively reduced cell temperatures and improved temperature uniformity, resulting in increased output power and electrical efficiency for the HCPV cell module.
Article
Thermodynamics
Qing-Hui Wang, Zhan-Hui Wu, Zhi-Jia Xu, Xiao-Lin Fang, Hao Zhao, Ying-Jun Wang, Da-Xiang Deng
Summary: This study proposes an optimization method based on design of experiments and response surface methodology, using a decoupling strategy to optimize the groove parameters of the composite porous vapor chamber. The results show that the groove parameters have a nonmonotonic effect, with groove depth having the greatest influence on thermal hydraulic characteristics. The optimal groove parameter configuration can reduce the maximum temperature, maximum temperature difference, and liquid pressure drop, providing a more objective and scientific design method for CPVC structural parameters.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Cong Li, Jiali Wang, Chenhui Wang, Yanke Jin, Yina Yao, Rui Yang
Summary: This study investigates the impact of NaCl water droplets with various concentrations on a heated surface. The results show that the impact patterns can be categorized into different types, and models are established to predict the spreading behavior of droplets with different concentrations. Additionally, high concentration droplets exhibit more violent boiling and have lower residual energy and rebound time.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
C. Barrera, V. Castro, F. Escudero, J. J. Cruz, I. Verdugo, J. Yon, A. Fuentes
Summary: This study focuses on the characterization of soot maturity and sooting propensity of anisole fuel in a controlled laminar coflow diffusion flame. The results show that the spatial distribution of soot volume fraction is enhanced near the flame centerline, while soot production is promoted near the flame wings. The temperature increase also affects the maturity of soot particles.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Roman W. Morse, Jason Chan, Tiago A. Moreira, Jared J. Valois, Evan T. Hurlburt, Jean-Marie Le Corre, Arganthael Berson, Kristofer M. Dressler, Gregory F. Nellis
Summary: This study investigates the dryout of liquid film and the role of disturbance wave frequency. Experimental results indicate that the heat transfer coefficient associated with optimal boiling conditions is maximized when the surface is dry 5% of the time, independent of pulse amplitude and frequency. Liquid-film measurements, dryout statistics, and direct observation suggest that disturbance-wave frequency can be manipulated by density-wave oscillations in the flow field.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
E. J. Vega, J. M. Montanero
Summary: In this study, we experimentally investigated the bursting of a bubble covered with a surfactant. We found that the bubble bursting time is longer compared to a surfactant-free bubble due to interfacial elasticity. Furthermore, the Marangoni stress drives liquid flow that allows the jet to escape from the end-pinching mechanism within a certain surfactant concentration range.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Guofu Sun, Yi Zhan, Tomio Okawa, Mitsuhiro Aoyagi, Akihiro Uchibori, Yasushi Okano
Summary: Experiments were conducted on liquid jets ejected from oval nozzles to investigate the effects of nozzle orifice shape on jet behavior. The study found that the liquid jet exhibited different characteristics at different liquid flow rates. Correlations were established to predict the liquid jet state and characteristics of the secondary droplets produced during jet impact onto a solid surface. This research extended the available knowledge on liquid jet behavior.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Jeonghoon Lee, Laurent Zimmer, Takeshi Saito, Shinji Nakaya, Mitsuhiro Tsue
Summary: This study investigates the effects of spatial resolution on DMD amplitudes and spatial mode strengths, and proposes scaling factors to correct for the resolution differences. The results show that the proposed scaling factors successfully normalize the amplitudes and spatial modes, allowing for quantitative comparison of data obtained with different spatial resolutions. This study is significant for analyzing spatiotemporal data in various fields.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Yanli Zhao, Shibing Kuang, Xiaoliang Zhang, Mingjun Xu
Summary: This study experimentally investigates the dynamic process of water droplet impacting different wood surfaces and analyzes and discusses the impacting phenomena, phenomena distribution, droplet spreading dynamics, and maximum spread factor. The results show that the impacting process can be distinguished by Weber numbers and Reynolds numbers, and can be predicted by mathematical expressions.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Aakhash Sundaresan, Atul Srivastava, Callum Atkinson
Summary: This study presents the first-ever application of an advanced methodology, combining two-color laser-induced phosphorescence and particle image velocimetry, to investigate the heat transfer mechanisms on the surface of a cylinder placed inside a confined square duct. The technique allows for simultaneous measurement of velocity and temperature fields, reducing the complexity and costs associated with separately measuring temperature distributions. Experimental observations show that increasing the mass flow rate enhances heat removal from the cylinder surface, and increasing the cylinder heat input enhances heat transfer in the rear portion of the cylinder.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Harish K. Patel, Sukhjeet Arora, Rutuja Chavan, Bimlesh Kumar
Summary: This study experimentally analyzed the multiscale statistical assessment of scour depth surrounding spur dikes with downward seepage. The research found that seepage affects the morphological behavior and hydrodynamic characteristics of the channel bed, leading to changes in scour formation. The rate of scour depth changes initially increases with higher seepage velocity but eventually becomes constant over time.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Justas Sereika, Paulius Vilkinis, Gediminas Skarbalius, Algis Dziugys, Nerijus Pedisius
Summary: This study experimentally investigated the pulsatile flow structure based on a transitional-type cavity. It was found that the pulsation amplitude has a more significant effect on the dynamics of recirculation zone than the pulsation frequency. Pulsatile flow can reduce the size of the recirculation zone.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Merav Arogeti, Eran Sher, Tali Bar-Kohany
Summary: This study provides a detailed exploration of the events that occur when a droplet hits a dry solid surface of various small sizes, with a focus on the deposition, receding breakup, and prompt splash phases. By utilizing non-dimensional analysis and graphical representation, the boundaries between different events are defined, and criteria for differentiation based on target-to-drop ratio, Reynolds, and Webber numbers are presented.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Tianxiong Li, Fei Wen, Yingchun Wu, Botong Wen, Lei Wang, Jinxin Guo, Xuecheng Wu
Summary: This study investigates the structure of the flow field induced by a strut in a scramjet and its influence on flame stabilization. Experimental and numerical analyses reveal that the flow field exhibits features beneficial for flame stabilization, but the asymmetry of the flow poses a challenge to flame establishment.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Syed Ehtisham Gillani, Yasir M. Al-Abdeli
Summary: This study investigates the asymmetry in bluff-body stabilised annular jets and finds that swirl can significantly mitigate the asymmetry and restore the symmetry of the jets. Moreover, increasing the Reynolds number and the swirl intensity can both decrease the asymmetry of the jets.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Utsav Bhardwaj, Rabindra Kumar, Shyama Prasad Das
Summary: This study presents an experimental investigation on flooding phenomenon in a pulsating heat pipe (PHP) unit cell, and analyzes the impact of flooding on the performance of PHP. The study recognizes three different flooding mechanisms and finds that currently accepted correlations for predicting flooding velocity are inaccurate. The study emphasizes the need for further research on flooding in PHPs.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Yunpeng Xue, Yongling Zhao, Shuo-Jun Mei, Yuan Chao, Jan Carmeliet
Summary: This study investigates the impact of building morphology on local climate, air quality, and urban microclimate. The researchers conducted an experimental investigation in a large-scale water tunnel, analyzing heat and flow fields using Laser-induced Fluorescence (LIF) and Particle Image Velocimetry (PIV). The findings show that factors such as canyon configuration, buoyant force, and approaching flow magnitude significantly influence fluid flow in street canyons, and the morphology of the street canyon dominates ventilation rate and heat flux. For example, changing the aspect ratio of a street canyon can lead to a significant change in air ventilation rate, ranging from 0.02 to 1.5 under the same flow conditions.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
