Article
Mechanics
Wenhan Zheng, Fangjun Hong, Shuai Gong
Summary: In this paper, the thermal pseudo-potential lattice Boltzmann method (LBM) is improved by introducing multi-relaxation time operators and deriving dimensionless evolution equations. The accuracy and efficiency of the method are further enhanced by improving the energy equation, adopting a more accurate equation of state, and modifying the surface tension coefficient. Moreover, a three-layer boundary structure is proposed to incorporate the intermolecular force and internal heat source term. These improvements enable efficient and accurate simulation of liquid-vapor phase transition.
Article
Thermodynamics
Artur Carvalho Santos, Fernando Luiz Sacomano Filho, Aymeric Vie
Summary: A general gas-phase energy formulation can be obtained independently from the species diffusion transport modeling while incorporating multi-species enthalpy diffusion terms. The choice of specific heats characterizes the inclusion or not of multi-species enthalpy diffusion effects. The proposed energy formulation is evaluated by conducting simulations for droplets of multiple fuel compositions in varied atmospheric conditions to represent spray combustion scenarios and concludes on its need and ease of use.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
W. Yang, J. Xia, X. Y. Wang, K. D. Wan, A. Megaritis, H. Zhao
Summary: This study investigates the effects of more realistic evaporation models based on non-ideal vapour-liquid equilibrium on the evaporation dynamics of multicomponent droplets and sprays. The use of the UNIFAC model for determining activity coefficients shows good agreement with measurements, and it is crucial for properly predicting evaporation processes of different compositions. The study highlights the significant impact of non-ideal vapour-liquid equilibrium models on predicting the evaporation of multi and many-component droplets and sprays, emphasizing the advantages of the UNIFAC method in such cases.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Siyu Xie, Yunpeng Fu, Ping Yi, Tie Li, Run Chen
Summary: The transitional behavior of multi-component sprays under ECN Spray-A conditions has been investigated using numerical methods in this study. The development and implementation of robust thermodynamic equilibrium solvers and multi-component droplet evaporation models in OpenFOAM have led to new insights. The results indicate that dilute sprays are more prone to transitioning to the supercritical mixing regime, while dense sprays experience a decrease in trans-critical possibility before the end of injection due to the cooling effect of extensive evaporation. Additionally, it was found that multi-component diesel sprays are more likely to transition to the supercritical regime than n-dodecane sprays due to their low mixture critical temperature and evaporation rate.
APPLIED THERMAL ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Olivier J. J. Ronsin, DongJu Jang, Hans-Joachim Egelhaaf, Christoph J. Brabec, Jens Harting
Summary: In solution processing of thin films, the evaporation kinetics of fluid mixtures play a crucial role in determining the final morphology and properties of the film. A new phase-field model is proposed to simulate the evaporation kinetics of these mixtures, focusing on local liquid-vapor equilibrium and diffusion at the film surface. The simulations show that the evaporation rate is time-dependent for mixtures due to changing composition, but can become almost constant for highly nonideal mixtures in certain conditions.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Sajad Jafari, Hesham Gaballa, Chaouki Habchi, Jean-Charles De Hemptinne, Pascal Mougin
Summary: This paper focuses on the analysis of the coupling between the hydrodynamics and thermodynamics of multi-species supercritical jets. Various phase transition phenomena are studied, and a tabulated multi-component real fluid model is proposed for simulation. Numerical results show good agreement with experimental data and previous studies. The relevance of different turbulence models is also examined, indicating the importance of the LES Sigma model in these complex two-phase flows.
JOURNAL OF SUPERCRITICAL FLUIDS
(2022)
Article
Thermodynamics
Milad Ahmadi Khoshooei
Summary: Vapor pressure data and evaporation/sublimation rate of liquid samples are crucial parameters for designing new process units, requiring consideration of limitations and analysis precautions associated with traditional methods in order to obtain valuable data.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Thermodynamics
Hesham Gaballa, Sajad Jafari, Chaouki Habchi, Jean-Charles de Hemptinne
Summary: This study proposes a real-fluid model for two-phase flow in dual-fuel internal combustion engines, aiming to investigate the evaporation and mixing processes of renewable fuels. The model is applied to analyze the evaporation of n-dodecane in a mixed ambient, showing that increasing methanol concentration reduces the droplet lifetime. Thermodynamic analysis reveals different thermodynamic paths for the droplet under varying methanol concentrations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Environmental
Maanasa Bhat, Shengfeng Luo, Jianan Zhang, Chuwei Zhang, Bo Zhou, Sili Deng
Summary: Spray synthesis methods are highly attractive for manufacturing energy storage and conversion materials due to their scalability and controllability. This study analysed the evaporation process of multi-component precursor droplets used in flame-assisted spray pyrolysis of NCM811 cathode materials, providing insights into the connection between evaporation process and final product structure. The study contributes towards improving the design of spray drying and synthesis processes.
CHEMICAL ENGINEERING JOURNAL
(2024)
Article
Thermodynamics
Fernando Luiz Sacomano Filho, Artur Carvalho Santos, Aymeric Vie, Guenther Carlos Krieger Filho
Summary: Liquid fuels used in spray combustion processes are composed of mixed components, forming multi-component liquid droplets that undergo complex heat and mass transfers in various atmospheric conditions. Existing models have limitations in characterizing these interactions, prompting the proposal of a novel modeling strategy. The new model, derived from general transport equations of the gas phase, proves to be efficient in all tested scenarios, showing differential diffusion effects among participating species for mass and heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
M. Mohib Ur Rehman, Gyoko Nagayama
Summary: In this study, it was found that the presence of micro/nanostructured surfaces significantly affects the evaporation rate of droplets, with the wettability and volume of the droplets further influencing this effect. Theoretical and experimental results showed agreement when the scale of the solid-liquid-vapor interface (slv) was negligible. For microstructured surfaces, the scale of the slv interface could reach 253-940 μm, and the evaporation rate at the slv interface accounted for 16-48% of the total evaporation rate. The scale and rate of the slv interface increased with a decrease in the initial contact angle or an increase in the droplet volume. These findings are important for practical engineering and medical applications involving droplet evaporation on micro/nanostructured surfaces.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Thermodynamics
Irina A. Graur, Elizaveta Ya. Gatapova, Moritz Wolf, Marina A. Batueva
Summary: The study simulated the evaporation process and found that the S-model kinetic equation is a time-effective model for simulating the structure inside and beyond the Knudsen layer, while the moment method of the solution of the Boltzmann equation also yielded results in good agreement with molecular dynamics data.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Anirban Chandra, Zhi Liang, Assad A. Oberai, Onkar Sahni, Pawel Keblinski
Summary: The study examines the efficiency of continuum methods in modeling multi-phase flow at large scales and raises questions about their applicability to nanoscale systems. It also emphasizes the importance of appropriate constitutive relations at liquid-vapor interfaces for correctly representing the dynamics of the specific problem of interest. The results suggest that with certain approaches, interfacial phenomena can be accurately described in the context of liquid-vapor phase change.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Thermodynamics
Irina A. Graur, Marina A. Batueva, Moritz Wolf, Elizaveta Ya. Gatapova
Summary: This article conducts numerical simulations of monatomic vapor condensation on its liquid phase using three different methods. The results show good agreement among these methods for monatomic gases. The Moment Method is found to have great potential for efficient estimation of condensation fluxes while respecting the conservation of mass, momentum, and energy. The study also discusses the presence and effects of an inverted temperature gradient during the condensation process, and proposes a methodology for extracting the condensation coefficient based on the Moment Method results.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Multidisciplinary Sciences
Ming Zhou, Haomin Song, Xingyu Xu, Alireza Shahsafi, Yurui Qu, Zhenyang Xia, Zhenqiang Ma, Mikhail A. Kats, Jia Zhu, Boon S. Ooi, Qiaoqiang Gan, Zongfu Yu
Summary: Researchers have developed daytime radiative condensers that can operate 24 hours a day without active energy consumption, producing water from vapor under direct sunlight. This new technology can significantly enhance the performance of passive vapor condensation for water extraction and purification applications.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Thermodynamics
Xinyi Zhou, Tie Li, Zheyuan Lai, Shuai Huang
Summary: This article analyzes the scaling relationship between small and large bore diesel engines, as well as the application of split injection strategies. It is found that all three scaling rules can effectively scale the injection rate and mass, with the pressure rule being better for scaling spray tip and tail penetrations.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Thermodynamics
Xinyi Zhou, Tie Li, Ping Yi
Summary: In this paper, a new 0-D model describing the spray development during the transient processes at the start of injection in diesel engines is proposed. Experimental results show that the spray tip penetration behavior deviates from conventional models, providing valuable insights for engineers and researchers.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Energy & Fuels
Ping Yi, Tie Li, Yunpeng Fu, Siyu Xie
Summary: The study focuses on the micro-explosion of blended ethanol-diesel droplets under diesel engine-like conditions, using a model to predict the bubble generation, growth, and explosion process. It is found that the heat transfer rate and superheat limit are predominant factors under low pressures, while the competition among evaporation rate, heating rate, transcritical transition, and bubble growth rate determines the micro-explosion under higher pressures.
Article
Thermodynamics
Siyu Xie, Yunpeng Fu, Ping Yi, Tie Li, Run Chen
Summary: The transitional behavior of multi-component sprays under ECN Spray-A conditions has been investigated using numerical methods in this study. The development and implementation of robust thermodynamic equilibrium solvers and multi-component droplet evaporation models in OpenFOAM have led to new insights. The results indicate that dilute sprays are more prone to transitioning to the supercritical mixing regime, while dense sprays experience a decrease in trans-critical possibility before the end of injection due to the cooling effect of extensive evaporation. Additionally, it was found that multi-component diesel sprays are more likely to transition to the supercritical regime than n-dodecane sprays due to their low mixture critical temperature and evaporation rate.
APPLIED THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Yijie Wei, Tie Li, Run Chen, Xinyi Zhou, Zhifei Zhang, Xinran Wang
Summary: This study investigated the gas entrainment process in the breakup length of diesel spray using the high-speed micro-PTV technique. The experimental results showed that the gas entrainment velocity increased with higher injection pressure, while ambient density had no significant impact on the entrainment velocity. The study also proposed a theoretical 0-D model to estimate the cumulative gas entrainment rate during the quasi-steady state, which was validated with the experimental results.
Article
Thermodynamics
Shuai Huang, Tie Li, Xinran Wang, Run Chen, Rundai Yang, Zhonghua Qian
Summary: Research indicates that for natural gas engines under diluted combustion conditions, increasing ignition discharge energy or duration can promote successful ignition, while multiple discharges also contribute to ignition stability.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2022)
Article
Thermodynamics
Ruitian He, Ping Yi, Tie Li, Yanzhi Zhang, Run Chen
Summary: This study investigates the non-equilibrium evaporation and transcritical transition processes of n-heptane/ethanol blends under pure nitrogen condition. A new transcritical criterion for multi-component mixtures is proposed based on molecular dynamics simulation. The study validates the employed force fields for n-heptane/ethanol blends and captures azeotropic phenomena through macroscopic distillation experiments. The results reveal the influence of non-equilibrium on near-azeotropic occurrence and the accelerated evaporation rate with increased ethanol concentration. Additionally, the traditional criterion for transcritical transition is found to be insufficient.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Chemical
Pengcheng Zhao, Tie Li, Ang Li, Yongzhi Ma, Mingming Fang, Xinling Li
Summary: This study investigated the particle volatility, size distribution, and composition of parent and alkylated polycyclic aromatic hydrocarbons (PAH/alkyl-PAHs) during toluene pyrolysis. The results showed that long residence times and high temperatures resulted in higher particle mass concentrations, lower particle volatility, and a shift towards larger particle sizes. The total particle number concentrations exhibited a rise-then-fall trend with increasing temperature, indicating a transition from nucleation to agglomeration and coagulation. The PAHs and alkyl-PAHs with 2-4 rings showed the highest concentrations at 950 degrees C for 0.2 s, and appeared at 1050 degrees C for 0.5 s and 0.8 s, consistent with the critical temperature of particle nucleation at long residence times. The particle peak number concentrations and total PAH mass concentrations showed consistent temperature dependence, suggesting a strong relationship between soot nucleation and PAH concentrations.
AEROSOL SCIENCE AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Shiyan Li, Tie Li, Ning Wang, Xinyi Zhou, Run Chen, Ping Yi
Summary: This study investigates the spray characteristics of ammonia under different temperatures and densities, and establishes a non-dimensional analysis to quantitatively compare the key factors with bubble explosion intensity of different fuels. The results show that the superheat degree and fuel viscosity play significant roles in the spray evaporation process.
Article
Chemistry, Applied
Tengfei Wang, Run Chen, Hao Jiang, Xinqi Qiao, Tie Li
Summary: This study uses high resolution transmission electron microscopy to analyze the formation mechanism of soot particles during the combustion of commercial diesel fuel and emulsified fuel with water-containing ethanol. The results indicate that the soot particles derived from emulsified fuel are less mature but have higher oxidation reactivity compared to diesel fuel.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Thermodynamics
Shiyan Li, Tie Li, Ning Wang, Xinyi Zhou, Ping Yi, Run Chen
Summary: Direct injection of liquid ammonia has the potential to reduce greenhouse-gas emissions while maintaining engine power output, especially under high replacement ratio conditions. This study used micro-imaging, Schlieren, and diffused backlit imaging techniques to investigate the gasification process and near-field characteristics of ammonia spray. The experimental results showed significant gasification and near-field volume increment inside and outside the nozzle under high fuel temperature conditions. The linear increment of the gasification ratio exponentially accelerated the two-phase distribution area of ammonia spray, providing valuable insights for simulation models.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Xinyi Zhou, Tie Li, Ning Wang, Xinran Wang, Run Chen, Shiyan Li
Summary: The decarbonization of global shipping is crucial in mitigating climate change, and ammonia has been identified as a sustainable and zero-carbon fuel for the maritime industry. Despite existing studies primarily focusing on automotive engines, research on marine low-speed engines is limited. This paper establishes numerical models for a pilot diesel-ignited ammonia dual-fuel engine, utilizing a commercial low-speed marine diesel engine as a prototype. The models are validated with experimental data, and engine performance and emissions are studied and optimized under both premixed and high-pressure spray combustion modes.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Green & Sustainable Science & Technology
Shoaib Ahmed, Tie Li, Ping Yi, Run Chen
Summary: This study assessed the environmental impacts and performance of a newly built green ammonia-powered tanker, and found that green ammonia has lower environmental impact compared to other fuels. Adequately managing the ammonia-powered marine energy system is crucial for reducing environmental footprints and lowering carbon, nitrogen oxide, and ammonia-based emissions.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Energy & Fuels
Tie Li, Xinyi Zhou, Ning Wang, Xinran Wang, Run Chen, Shiyan Li, Ping Yi
Summary: Ammonia, as a carbon-free fuel, has great potential for decarbonization in marine engines. The dual-fuel mode can compensate for the poor combustion properties of ammonia. The study shows that in the low-pressure injection dual-fuel mode, the recommended maximum ammonia ratio is about 80% by energy, while the high-pressure injection dual-fuel mode has the potential to achieve a 97% diesel replacement ratio. Compared with the pure diesel mode, the high-pressure injection dual-fuel mode can reduce the equivalent CO2 emissions.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Engineering, Multidisciplinary
Ping Yi, Yunpeng Fu, Tie Li
Summary: Spray simulations require calibration of empirical constants in the break-up model for accurate predictions. Droplet evaporation affects the calibration of the break-up model, especially under high pressures. An accurate multi-component evaporation model is suggested to reduce the dependence of break-up constants on ambient conditions.
ATOMIZATION AND SPRAYS
(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)
