Article
Thermodynamics
Yu-Jie Chen, Kong Ling, Shu-Qi Jin, Wei Lu, Bo Yu, Dongliang Sun, Wei Zhang, Wen-Quan Tao
Summary: In this study, the VOSET method is used to investigate the critical heat flux (CHF) of subcooled flow boiling in a vertical rectangular mini-channel. The relationship between boiling crisis and dry patch is demonstrated, and a new triggering mechanism is proposed. The results show that the appearance of an almost permanent dry patch with high local wall superheating is caused by the continuous coalescence of elongated bubbles midstream and downstream.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Jingchao Lu, Dawei Zhuang, Yueming Wang, Guoliang Ding
Summary: This paper presents a new idea to enhance heat transfer of subcooled flow boiling by inserting a vortex generator to accelerate bubble departure from the heating wall of flow channel. Experimental studies were conducted to investigate the effects of vortex generator positions and working fluid conditions on the heat transfer characteristics. The results showed that the vortex generator effectively enhanced the heat transfer in subcooled flow boiling, with a maximum increase of the heat transfer coefficient and the critical heat flux of 8.4 x 103 W m-2 s-1 and 21.8%, respectively. A new correlation was developed to predict the heat transfer coefficients of vortex enhanced subcooled flow boiling, which exhibited good agreement with the experimental data.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Shichang Dong, Shengjie Gong, Botao Zhang, Zhenqin Xiong, Yidan Yuan, Weimin Ma
Summary: The in-vessel retention system and ex-vessel retention system play a crucial role in ensuring the safety of nuclear power plants during severe accidents. However, accurately predicting the subcooled flow boiling curve and critical heat flux (CHF) remains a challenge, especially under low-pressure and low-flow conditions with complex boiling phenomena. This study presents a theoretical model that effectively predicts the boiling curve and CHF for subcooled flow boiling in inclined downward heated rectangular channels. The model considers bubble growth and interaction, and accurately estimates the transition from forced convection to fully developed boiling regime. Through probability analysis and validation experiments, the model demonstrates good applicability in predicting boiling curves and CHF under various thermal-hydraulic parameters, with a prediction error within ±15%.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Ichiro Kano, Hideyuki Nagao, Makoto Iyoda
Summary: This study examined the performance of a micro-slit-channel heat sink for cooling electrical devices. The study characterized the flow-boiling performance of a dielectric liquid and evaluated the heat transfer performance of an electroplated diamond surface. Various parameters were tested, including electric field intensity, mass flow rate, and inlet subcooling. The results showed four different flow boiling patterns and identified the maximum critical heat flux and heat transfer coefficient under specific conditions.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
V Scheiff, F. Bergame, J. Sebilleau, P. Ruyer, C. Colin
Summary: This study investigates the heat transfer and flow structure in the fully developed nucleate flow boiling regime in a semi-annular duct. The experiments show that the wall heat flux prediction and bubble diameter variation can be well explained and predicted under different parameter conditions.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Kai Zhang, Jingshan Yang, Xiulan Huai, Keyong Cheng
Summary: A novel design of opposed wall jet subcooled boiling is proposed to improve the instability of flow boiling. By adopting a small chamber as the boiling space, sufficient space for bubble expansion is provided, and the detached bubbles rapidly collapse into microbubbles in the subcooled liquid, preventing blockage of the flow passage by large bubbles. This design results in significantly smaller transient fluctuations of temperature and pressure, as well as pressure drop characteristics independent of heat flux.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Bin Liu, Bo Yuan, Jie Zhou, Jianfu Zhao, Paolo Di Marco, Yonghai Zhang, Jinjia Wei, Yang Yang
Summary: This study investigated the critical heat flux (CHF) of subcooled flow boiling at different gravity levels on smooth silicon surfaces. It was found that CHF increases with the increase of channel height and flow velocity, but decreases with the increase of heater length. Dimensionless analysis revealed the relationship between flow velocity, heater length, channel geometrical parameters, and the ratio of CHF in microgravity to that in normal gravity. A correlation for predicting this ratio was developed based on the dimensionless analysis, showing good agreement with experimental data within +/- 10%.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2021)
Article
Thermodynamics
P. Liu, Y. S. Guo, W. L. Zheng, Y. T. Song, X. B. Peng, M. Y. Tang, W. H. Wang, S. F. Huang, J. D. Ji, Q. H. Chen, X. Mao
Summary: The novel compound heat transfer tube (CHTT) combining twisted tape inserts and internal thread tube showed better performance in enhancing subcooled critical heat flux (CHF) compared to individual techniques. CHF in CHTT was directly proportional to pitch, mass flux, and pressure, while inversely proportional to twist ratio. Tong-75-II correlation provided the most accurate prediction of CHF in CHTT, with a mean absolute error (MAE) of 32.80% and a root mean square error (RMSE) of 33.72%.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Haidong Liu, Erlei Zhao, Deqi Chen, Jiang Qin, Peigang Yan, Wei Liu, Hanzhou Liu
Summary: This paper presents a visual experiment to investigate the vapor-liquid interfacial features near the heating wall in subcooled flow boiling, aiming to reveal the mechanism of boiling crisis. Through qualitative and quantitative analysis, the study identifies the thickness of the vapor layer, as well as the wavelength of the vapor layer and the liquid film, as key parameters for the developing boiling crisis trigger mechanism.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Yu-Jie Chen, Kong Ling, Hao Ding, Yun Wang, Shu-Qi Jin, Wen-Quan Tao
Summary: A three-dimensional conjugated numerical simulation is conducted using the interface capturing method to investigate subcooled flow boiling in a horizontal rectangular mini-channel. The simulation successfully captures hundreds of bubbles with different sizes and reproduces the typical processes and flow boiling patterns. The effects of heat flux and vapor fraction on heat transfer coefficient are discussed, and the heat transfer mechanisms of subcooled flow boiling at different heat flux in the present mini-channel are explored.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Stanislawa Halon, Zbigniew Krolicki, Remi Revellin, Bartosz Zajaczkowski
Summary: Flow boiling in micro channels is a promising solution for electronics cooling, but its development is hindered by the lack of understanding of heat exchange mechanisms and instabilities. This study experimentally determined the dominant heat transfer mechanism of R245fa in micro channels and investigated the impact of inlet restrictions on thermal performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Junsoo Yoo, Carlos E. Estrada Perez, Yassin A. Hassan
Summary: This paper discusses the sliding bubble velocity in flow boiling systems and introduces a new force balance model that outperforms previous models in predicting sliding bubble velocity and growth accurately.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Wei-Ting Hsu, Namkyu Lee, Donghwi Lee, JeongJu Kim, Maroosol Yun, Hyung Hee Cho
Summary: Recent research has focused on anisotropic wicking surfaces, which show improved boiling heat transfer by using bent polymerized pillar arrays compared to surfaces with vertically polymerized pillars. Experimental results confirmed the enhancements of critical heat flux and heat transfer coefficient on anisotropic wicking surfaces, and the relationship between liquid pinning forces and polymerized pillar surfaces was theoretically analyzed for a better understanding of the enhanced boiling heat transfer during subcooled flow boiling.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Li Chang, Ali S. Rangwala
Summary: Turbulence has a significant impact on nucleate boiling heat transfer, with increased turbulence leading to enhanced heat transfer efficiency, as reflected in bubble departure frequency, critical heat flux, and bubble behaviors.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Steven J. Darges, V. S. Devahdhanush, Issam Mudawar, Henry K. Nahra, R. Balasubramaniam, Mohammad M. Hasan, Jeffrey R. Mackey
Summary: This study investigates the critical heat flux (CHF) for subcooled flow boiling of n-Perfluorohexane based on experiments conducted in the Flow Boiling and Condensation Experiment (FBCE) onboard the International Space Station (ISS). The results show that the CHF increases with higher flow rate and inlet subcooling. The Interfacial Lift-off Model is used to predict the CHF, and it exhibits good predictive capability.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
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)