Article
Thermodynamics
Ziliang Rui, Hong Sun, Jie Ma, Hao Peng
Summary: This study investigates the flow boiling of SDS aqueous solution in straight and tree-shaped microchannels and its effect on heat transfer and pressure drop. The results show that SDS can enhance heat transfer, suppress the formation of vapor slugs, and promote rewetting of the channel surface. Additionally, SDS can extend the stable nucleate boiling state. Increasing SDS concentration leads to higher pressure drop and pressure drop fluctuation, but increasing volume flow rate can mitigate these effects.
Article
Thermodynamics
Abdullah Masoud Ali, Matteo Angelino, Aldo Rona
Summary: The study investigates the hydraulic and thermal performance of microchannel heat sink configurations for high performance electronic cooling applications using numerical modelling. Results show that inserting zig-zag fins and using 3% Al2O3 nanofluid coolant in the ducts significantly improve heat transfer efficiency and reduce contact temperature.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
R. Vinoth, B. Sachuthananthan
Summary: The study compared the heat transfer performance of pentagonal and triangular channel oblique finned microchannel heat sinks using different nanofluids, with results showing that the pentagonal channel heat sink performed better in heat transfer and increased pressure drop when using hybrid nanofluid.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
R. Vinoth, B. Sachuthananthan, A. Vadivel, S. Balakrishnan, A. Gnana Sagaya Raj
Summary: The experimental study analyzed the heat transfer characteristics of an oblique finned curved microchannel heat sink with different working fluids. The results showed that the curved microchannel heat sink had higher heat transfer rate, PEC and pressure drop compared to the straight channel heat sink. When using a hybrid nanofluid, the heat transfer rate of the curved microchannel heat sink was also higher.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Houpei Li, Pega Hrnjak
Summary: This paper presents the measurements of flow boiling heat transfer coefficient and pressure gradient for R32 and R1234yf mixtures in a microchannel tube. The results show that mass flux has a significant effect on both heat transfer coefficient and pressure gradient, while heat flux only affects the heat transfer coefficient. Furthermore, the temperature glide curve has an impact on the heat transfer coefficient.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Imene Rahmoune, Saadi Bougoul
Summary: This study presents an analysis of heat transmission and magnetic nanofluid flow in a minichannel with corrugated upper wall and exposed to a magnetic field. The results show that magnetic nanofluid subjected to a magnetic field acts as an active vortex generator, improving fluid mixing and heat transmission. Increase in magnetic field strength and volume fraction has a positive effect on flow structure and heat transfer.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Kai Fu, Wuhuan Gao, Xianghua Xu, Xingang Liang
Summary: This study experimentally investigates the flow boiling phenomenon of water in a copper foam fin microchannel (FFMC) heat sink. The results show that the heat transfer coefficient of the FFMC is improved by 80%, and the pressure drop is increased by 1.2 to 2 times compared to a solid fin microchannel (SFMC) heat sink. Furthermore, the critical heat flux of the FFMC is improved by 25% and the flow instability is significantly mitigated.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Yanhong Sun, Ao Huang, Jinli Lu, Yuyan Jiang
Summary: This study experimentally investigated the heat transfer characteristics and dynamic flow boiling instabilities of ethanol in a rectangular microchannel. The results showed that the inhibition of bubble nucleation caused by large bubbles in the confined space led to a deterioration in heat transfer performance. Higher mass flux resulted in more effective bubble nucleation and better heat transfer. The triggering of flow boiling instability in the microchannel was strongly dependent on quasi-periodical flow phenomenon and multiphase alternation. The thermophysical properties of the working liquid significantly affected the fluctuation amplitude.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Chinmaya Kumar Patra, Anandaroop Bhattacharya, Prasanta Kumar Das
Summary: A one-dimensional flow-boiling model is developed to study the pressure drop and heat transfer mechanism in a microchannel of rectangular cross-section under slug-flow regime. The model considers different stages of bubble growth and the periodic passage of different zones to evaluate the pressure drop and heat transfer coefficient. The results show that the channel dimension, flow velocity, heat flux, and working fluid properties have significant effects on the pressure drop and heat transfer coefficient.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Gaofeng Lu, Jianrong Yang, Xiaoqiang Zhai, Xiaolin Wang
Summary: This paper investigates hotspot-targeted thermal management using VGs in microchannels, showing that the adoption of VGs can significantly improve cooling effect over the hotspot with lower pressure loss.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Engineering, Chemical
Ying Zhang, Minqiang Pan
Summary: The study focused on the heat transfer performance and structural influence of N-structure microchannel heat exchangers. The arrangement of wave channel sections in the N-structure significantly affects the performance of the microchannel heat exchanger. The symmetrical N-structure was found to have the best heat transfer effect.
CHEMICAL ENGINEERING & TECHNOLOGY
(2021)
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)
Review
Thermodynamics
Shashank Singh, Anup Malik, Harlal Singh Mali
Summary: This article critically examines the research on modifications in geometry of channels for thermo-hydraulic performance enhancement and aims to determine the best channel configuration with optimal parameters. It explores various designs and their influencing parameters, as well as presents conclusions and potential recommendations for future research.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Tingbo Hou, Danmin Xu
Summary: This study investigates the influence of the ellipticity of an elliptical concave cavity on the pressure drop and heat transfer performance of a microchannel heat exchanger (MHE). The results show that an MHE with ellipticity 1.0 exhibits the best pressure drop and heat transfer performance.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Tran Dinh Manh, M. Marashi, Amir Mehdi Mofrad, Ali Hosseini Taleghani, Houman Babazadeh
Summary: This study investigates the use of tape with nanofluid to increase pressure drop and heat rate in heat exchangers. The efficiency of H2O-CuO nanofluid increases as Reynolds number increases, while the rate of exergy declines over 35% as the height ratio increases from 0.3 to 0.5.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
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)