Article
Thermodynamics
Zhiming Tan, Puhang Jin, Yingchun Zhang, Gongnan Xie
Summary: Due to advancements in micro manufacturing and 3D printing, the complex shape of microchannel heat sinks (MCHS) can now be achieved, allowing for improved heat transfer characteristics. In this study, a twisted tube geometry was applied to microchannels and the thermal and hydrodynamic performance of twisted square microchannels with jet impingement was investigated. The arrangement of the jet channels was studied, comparing one-jet and multi-jet microchannel heat sinks in terms of temperature profile, pressure drop, and heat transfer characteristics. The results showed that applying the twisted geometry increased the Nusselt number by 16.48% with minimal pressure drop increase. Furthermore, integrating jet impingement improved the thermal-hydrodynamic performance of MCHS, reducing thermal resistance by up to 41%. Finally, it was concluded that jet arrangement at torsion angles of 45 degrees, 135 degrees, and 225 degrees provided better performance. This study provides quantitative characterization of MCHS performance and guidance for jet arrangement design.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Huu Son Le, Ahmed M. Galal, Ibrahim Alhamrouni, Ayman A. Aly, Mohamed Abbas, Abdelaziz Salah Saidi, Thanh Hai Truong, Mahidzal Dahari, Makatar Wae-hayee
Summary: This study focuses on the optimization of heat transfer in modern micro-channel heat sinks. The response surface methodology is used to predict the Nusselt number and pressure drop of the coolant. By comparing the results of numerical calculations and the predictions of the response surface model, it is found that the response surface methodology can accurately predict the responses of the heat sink.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
D. D. Ma, Y. X. Tang, G. D. Xia
Summary: The sinusoidal wavy microchannels with secondary channels (SWSC) show better heat removal performance in flow boiling studies compared to conventional microchannels, thanks to increased bubble nucleation induced by enlarged surface area and continuous development of thin liquid film due to the introduction of secondary channels. However, the SWSC microchannels suffer from a higher pressure drop penalty.
APPLIED THERMAL ENGINEERING
(2021)
Article
Engineering, Chemical
I. Aguirre, A. Gonzalez, E. Castillo
Summary: This study numerically investigated the effects of vortex generators and changes in pin shape on flow characteristics in microchannel heat sinks. The results showed that the use of vortex generators significantly increased heat transfer rates, but also increased pressure drops in Newtonian fluids, while reducing pumping costs in shear-thinning fluids.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2022)
Article
Thermodynamics
A. Bejan, H. Almahmoud, U. Gunes
Summary: The article proposes a new approach of freely varying the aspect ratios of fins and flow channels simultaneously to achieve a complete high-density heat transfer flow architecture. It demonstrates that by specifying the combined solid and fluid volume and knowing the fluid flow rate, it is possible to predict the complete design of the flow configuration, including all aspect ratios, based on theory. The prediction power encompasses the overall heat transfer rate and required pumping power. The existence and performance of the design owe to the multiple degrees of freedom identified and utilized in the theory.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Xue-shuo Shang, Qing-wen Li, Qun Cao, Zi-rui Li, Wei Shao, Zheng Cui
Summary: This study develops a mathematical model of a rectangular microchannel heat sink (MCHS) and derives the thermal resistance using structural parameters based on the differential equation of energy conservation. Both experimental and numerical methods are employed to validate the model. A multiobjective optimization model is also established to simultaneously minimize the thermal resistance and the pumping power. The mathematical model and the multiobjective optimization method are beneficial for the design of an MCHS owing to the high convenience and reliability.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Haluk Anil Kose, Alperen Yildizeli, Sertac Cadirci
Summary: This study numerically investigates laminar single-phase fluid flow and conjugate heat transfer for three different shapes of microchannel heat sinks using Computational Fluid Dynamics (CFD). The study reveals the optimal geometric design variables for efficient microchannel heat sink designs. The results show that the rectangular microchannel configuration has the highest thermal and hydrodynamic performance among the three configurations.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Xuelai Zhang, Zhe Ji, Jifen Wang, Xin Lv
Summary: This paper provides a comprehensive review of the latest research progress in the design of microchannel flow channel layouts, enhanced structures within the flow channel, and combinations of microchannel structures. Different designs of microchannel flow channels, such as sawtooth, serpentine, bionic fractal, wavy, double-layer, and manifold, are summarized. The effects of enhanced structures, such as ribs, fins, cavities, and porous, on heat transfer performance and pump power loss are reviewed, and the effects of different combination methods on the heat dissipation performance, temperature uniformity, and pressure drop of the microchannels are analyzed.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Qifeng Zhu, Huixue Xia, Junjie Chen, Xinmin Zhang, Kunpeng Chang, Hongwei Zhang, Hua Wang, Jianfeng Wan, Yangyang Jin
Summary: Different groove shapes were studied to improve the overall performance of microchannel heat sinks, with the conclusion that arranging grooves on channel sidewalls can greatly enhance performance. Triangular grooves were found to be the optimal structure within a certain range of Reynolds numbers, while water-droplet shaped grooves offered significant advantages at higher Reynolds numbers.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Zhijian Duan, Gongnan Xie, Bo Yu, Puhang Jin
Summary: The study focuses on designing optimized structures for liquid-cooled microchannel heat sinks with different pin-fin arrays using the topology optimization method for better performance. The goal is to minimize flow energy dissipation and average temperature of the bottom surface to facilitate more efficient design of microchannel heat sinks for electronic chips' cooling.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Review
Thermodynamics
Hussam Sadique, Qasim Murtaza
Summary: This paper provides a comprehensive overview of heat transfer enhancement using microchannel heat sink (MCHS) through various techniques. The focus is on recent developments in cooling technologies, classification of flow channels, different methods for heat transfer enhancement, and geometric modifications in MCHS. Studies have shown that interrupting the boundary layer, inducing secondary flows, and chaotic advection in channels can promote heat transfer performance without significant changes in pumping power. Special emphasis is given to fractal shaped MCHS for reducing temperature non-uniformity with minimal pressure drop.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
H. Nemati, M. A. Moghimi, C. N. Markides
Summary: In this study, a novel type of air-cooled heat sink with mini-channels is proposed, which has higher heat transfer rates due to its smaller hydraulic diameter compared to conventional heat sinks. An innovative analytical method is used to predict the cooling performance, and numerical simulations are conducted to validate the results. A comparison with a plate-fin heat sink shows that the proposed design has a promising advantage in reducing entropy generation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Review
Thermodynamics
Akash Dwivedi, Mohammad Mohsin Khan, Harveer Singh Pali
Summary: A novel framework has been employed to enhance heat transfer in heat exchangers through microchannels. The use of nanofluids as working fluids shows better thermal behavior. Flow disrupters and ceramic microchannels can also improve heat transfer performance.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
G. Marseglia, M. G. De Giorgi, P. Pontes, R. Solipa, R. R. Souza, A. L. N. Moreira, A. S. Moita
Summary: This paper investigates the advantages and challenges of two-phase flows, specifically flow boiling of pure liquids and nanofluids, for cooling microchannel heat sinks. The study finds that even at low concentrations, the water-Au nanofluid exhibits superior cooling performance compared to other fluids, indicating that even small concentrations of nanoparticles can significantly impact heat transfer mechanisms.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Jian Song, Fei Liu, Yi Sui, Dalei Jing
Summary: This study numerically investigates the hydraulic and thermal performances of trapezoidal microchannel heat sinks, revealing that pressure drop increases with decreasing small-to-large end width ratio. Only TMCHS configurations with PCPFLI and RCCFLI show improved thermal performances as the ratio decreases, with lower thermal resistance and more uniform temperature distribution. The TMCHS with RCCFLI configuration exhibits the best overall thermal performance among the six configurations studied.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Biophysics
Yaw-Jen Chang, Sheng-Zheng Chen, Ching-Yuan Ho
COLLOIDS AND SURFACES B-BIOINTERFACES
(2015)
Article
Thermodynamics
Chun-ping Zhang, Yi-fu Lian, Cheng-Hsing Hsu, Jyh-tong Teng, Sheng Liu, Yaw-Jen Chang, Ralph Greif
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2015)
Article
Chemistry, Physical
Ching-Yuan Ho, Tzu-Hsuan Lin, Yaw-Jen Chang
JOURNAL OF ALLOYS AND COMPOUNDS
(2015)
Article
Thermodynamics
Ngoctan Tran, Yaw-Jen Chang, Jyh-Tong Teng, Thanhtrung Dang, Ralph Greif
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2016)
Article
Chemistry, Analytical
Yaw-Jen Chang, Yen-Juei Huang
SENSORS AND ACTUATORS B-CHEMICAL
(2016)
Article
Engineering, Electrical & Electronic
Ching-Yuan Ho, Yaw-Jen Chang
SOLID-STATE ELECTRONICS
(2016)
Article
Thermodynamics
Ngoctan Tran, Yaw-Jen Chang, Jyh-Tong Teng, Ralph Greif
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2017)
Article
Engineering, Biomedical
Kuo-Yi Weng, Yaw-Jen Chang, Ching-Yuan Ho, De Ue Liou, Yu-Tzu Huang, Wen-Yaw Chung, Ting-Yu Chin
JOURNAL OF MEDICAL AND BIOLOGICAL ENGINEERING
(2018)
Article
Chemistry, Multidisciplinary
Ching-Yuan Ho, Yi-Hua Fan, Yaw-Jen Chang
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
(2017)
Article
Engineering, Electrical & Electronic
Ching-Yuan Ho, Yew-Jen Chang
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2017)
Article
Biochemical Research Methods
Yaw-Jen Chang, Yi-Hua Fan, Shia-Chung Chen, Kuan-Hua Lee, Liao-Yong Lou
Article
Biophysics
Yaw-Jen Chang, Ching-Yuan Ho, Xin-Miao Zhou, Hsiu-Rong Yen
BIOSENSORS & BIOELECTRONICS
(2018)
Proceedings Paper
Engineering, Multidisciplinary
Yaw-Jen Chang, Xin-Miao Zhou, Hsiu-Rong Yen, Chih-Ling Yeh
2017 INTERNATIONAL CONFERENCE ON MECHANICAL, AERONAUTICAL AND AUTOMOTIVE ENGINEERING (ICMAA 2017)
(2017)
Article
Biochemical Research Methods
Yaw-Jen Chang, Cheng-Hao Chang
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)