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
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
Chemistry, Analytical
Maxim Pryazhnikov, Anton S. Yakimov, Ivan A. Denisov, Andrey Pryazhnikov, Andrey Minakov, Peter Belobrov
Summary: This article presents a new approach to determining the viscosity of Newtonian fluid based on the analysis of secondary Dean flow in a curved channel. The study of flow patterns of water and aqueous solutions of glycerin in a microfluidic chip with a U-microchannel was carried out, revealing a correlation between the Dean number and the flow recirculation angle.
Article
Engineering, Chemical
Shilpi Chatterjee, Kartik Chandra Ghanta, Abhiram Hens
Summary: An experimental and numerical simulation study of gas-liquid two-phase flow inside straight and spiral microchannels is presented, showing the influence of centrifugal force on Taylor bubble dynamics in spiral channels. The effect of gas-liquid flow ratio and hydrophobicity of channel wall on bubble formation was investigated, and the formation of Dean's vortices inside spiral microchannels was demonstrated through 3D CFD simulations. The presence of Dean's vortices in such microchannels can have potential applications in futuristic micro contrivances.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Mathematics, Interdisciplinary Applications
Fei Liu, Dalei Jing
Summary: This work presents a mathematical model to calculate the flowrate of combined EOF and PDLF in a symmetric tree-like microchannel network, with numerical analysis validating the model. The optimal diameter ratio for maximizing the flowrate is found to be dependent on various factors such as branching number, level, and channel length ratio. The transition of the optimal diameter ratio from N-1/3 for pure PDLF to N-1/2 for pure EOF is discussed in relation to the increasing ratio of driven voltage and pressure.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2021)
Article
Engineering, Marine
Songchen Yu, Hongde Qin, Peng Li, Fangyu Gong
Summary: This paper aims to understand the hydrodynamic characteristics of the biological fouling net in the open ocean, which is closely related to the safety of the offshore net cage and the survival environment of cultured fish. The equivalent model of the biofouling net is proposed, and the drag force coefficient and flow field variations are studied using large-eddy simulation (LES). The results show that the cross-sections contacted with fluid lead to a smaller drag force coefficient for 2 x 2 cruciform circular cylinder. The influence of net aperture and net twines on the wake is also assessed.
JOURNAL OF MARINE SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
Haiping Wen, Zhixuan Liang, Qingyi Luo, Chili Wu, Changhong Wang
Summary: In this study, the numerical simulation software ANSYS Fluent is used to optimize the microchannel heat sink structure with different types of ribs and secondary channels. The results show that the microchannel heat sink with front triangular ribs and secondary channel composite performs the best. It outperforms the conventional microchannel heat sink by up to 34% in terms of overall performance. Sensitivity analysis reveals the significant influence of relative rib width, flow rate, and relative secondary channel width on heat dissipation, pressure drop, and overall performance.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Biochemical Research Methods
Tingting Chen, Licong Cui, Wang He, Renxing Liu, Chengqiang Feng, Lei Wu, Yang Wang, Huiyun Liu, Linmao Qian, Bingjun Yu
Summary: As important components in microfluidic chip analysis systems, micromixers have shown wide applications. However, due to fabrication limitations, it is still challenging to achieve high-quality micromixers with both well-designed structures and efficient mixing. This study proposes a method based on the theory of chaotic mixing to design and fabricate sinusoidal structures with variable phases. The results demonstrate that the scratched traces with phase differences can resist etching, leading to the generation of misaligned sine channels with alternating 3D shapes. Further analysis shows that reducing the line spacing in scratching can result in a thicker a-Si layer. With the proposed method, a misaligned sine micromixer with higher mixing efficiency is achieved. The study also investigates the duplicating process for high-precision production of micromixers. Overall, this research provides strategies for miniaturizing high-performance microfluidic chips.
Article
Engineering, Multidisciplinary
Lianlian Xu, Yao Xu, Hailin Gu, Shuxia Qiu, Arun S. S. Mujumdar, Peng Xu
Summary: Inspired by natural bifurcating structures, tree-like microchannels have been utilized for microelectronics cooling. The thermal-hydraulic performance of a flat-plate tree-like microchannel is investigated through the optimization of successive branching ratios based on flow resistance minimization. The study reveals that the optimal successive diameter ratio follows Murray's law and the optimal successive length ratio follows the power law 2(-2/3). A mathematical model is developed for convection in a disc-shaped heat sink with a self-affine rough surface. The optimized flat-plate tree-like microchannel demonstrates enhanced thermal-hydraulic performance and sheds light on the design of micro-channel heat sinks and flow channels in cooling applications.
ENGINEERING APPLICATIONS OF COMPUTATIONAL FLUID MECHANICS
(2023)
Article
Multidisciplinary Sciences
Danica Sugic, Ramon Droop, Eileen Otte, Daniel Ehrmanntraut, Franco Nori, Janne Ruostekoski, Cornelia Denz, Mark R. Dennis
Summary: This study experimentally creates and measures a topological 3D skyrmionic hopfion in fully structured light, establishing the skyrmionic mapping by adjusting both polarization and phase profiles. The resulting light field's Stokes parameters and phase are synthesized into a Hopf fibration texture, allowing for volumetric full-field reconstruction of the Pi(3) mapping and measurement of a quantized topological charge. This research opens new avenues for 3D optical data encoding and metrology, providing experimentally-accessible photonic analogues to various particle-like 3D topological textures.
NATURE COMMUNICATIONS
(2021)
Article
Environmental Sciences
Liangqing Liu, Xiaoyuan Luo, Jianzheng Wang, Zhisai Shi, Fei Yan
Summary: Experimental PIV measurements were used to compare the wake characteristics of the smooth cylinder, the original grooved cylinder, and the secondary grooved cylinder. The results showed that the secondary grooved cylinder reduced the recirculation region, velocity gradient, Reynolds shear stresses, and turbulent kinetic energy. Both small-scale and large-scale vortices were present in the wake vortex shedding.
Article
Thermodynamics
Mohammad Jamshidmofid, Mehdi Bahiraei
Summary: The study investigates the hydrothermal characteristics of three types of nanofluid in Left-Right and Up-Down wavy microchannels, showing that the impact of nanofluids on convective heat transfer and temperature uniformity is more pronounced in the Up-Down microchannel.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Jiakuan Xu, Jianxin Liu
Summary: In this study, the primary and secondary instabilities in hypersonic boundary layers with different wall temperatures were compared. The results showed that the most dangerous Mack mode differed in the cooled-wall flow and the quiet wind tunnel condition. Additionally, the fundamental resonance dominated the secondary instability when the primary amplitude of Mack mode disturbances was large. The distributions of eigenfunctions of the fundamental modes and subharmonic modes were significantly affected by different wall temperatures.
Article
Thermodynamics
Muhammad Zia Ullah Khan, Bilal Akbar, Ramisha Sajjad, Umair Ahmed Rajput, Sanaullah Mastoi, Emad Uddin, Azhar Hussain, Md Yamin Younis, Fausto Pedro Garcia Marquez, Naveed Akram
Summary: This study investigates heat transfer enhancement in a straight rectangular channel with and without disturbances in the form of dimple protrusions. The results show that circular dimple-protrusion channels are effective for high Reynolds numbers, while through dimple protrusion channels are efficient for intermediate Reynolds numbers. Additionally, the addition of copper oxide nanoparticles improves heat transfer performance in the channels.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Mechanics
Xianliang Chen, Liang Wang, Song Fu
Summary: The nonlinear analysis of high-enthalpy and hypersonic boundary-layer transition, focusing on the impacts of thermal-chemical nonequilibrium (TCNE), received less attention compared to linear instabilities. The study used numerical tools such as the nonlinear parabolized stability equation (NPSE) and the Floquet analysis (SIT) on flow over a blunt cone at Mach 20. Results showed that the fundamental resonance dominated over subharmonic resonance, with good agreement between solutions from SIT and NPSE. Disturbances in species mass and vibrational temperature were mainly generated by the product term of wall-normal velocity disturbance and mean-flow gradient, with noticeable rope-like structures near the boundary-layer edge. TCNE led to larger maximum secondary growth rate and corresponding azimuthal wavenumber in secondary instability.
Article
Engineering, Electrical & Electronic
Jiading Wu, Zefeng Zhang, Huai Zheng, Sheng Liu
IEEE PHOTONICS TECHNOLOGY LETTERS
(2017)
Editorial Material
Engineering, Electrical & Electronic
Er-Ping Li, Zhizhang Chen, Chi-Hou Chan
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2017)
Article
Engineering, Electrical & Electronic
Xiang Lei, Huai Zheng, Xing Guo, Zefeng Zhang, Jiading Wu, Chunlin Xu, Sheng Liu
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2017)
Article
Thermodynamics
Ngoctan Tran, Yaw-Jen Chang, Jyh-Tong Teng, Ralph Greif
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2017)
Article
Thermodynamics
Ngoctan Tran, Yaw-Jen Chang, Jyh-Tong Teng, Ralph Greif
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2017)
Review
Engineering, Electrical & Electronic
Fulong Zhu, Yan Kan, Kai Tang, Sheng Liu
JOURNAL OF ELECTRONIC MATERIALS
(2017)
Article
Engineering, Industrial
Lixin Li, Lin Xiao, Hanqing Liao, Sheng Liu, Ben Ye
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(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
Physics, Multidisciplinary
Chenju Zheng, Jiajiang Lv, Shengjun Zhou, Sheng Liu
JOURNAL OF THE KOREAN PHYSICAL SOCIETY
(2017)
Article
Engineering, Electrical & Electronic
Ching-Yuan Ho, Yew-Jen Chang
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2017)
Article
Optics
Xinying Han, Hongqiao Wen, Sheng Liu, Yuchuan Xiong, Zhihui Luo
OPTICAL ENGINEERING
(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
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)
