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Influence of Multiple Electromagnetic Sources for Heat Transfer Improvement of Ferrofluid Flow inside the Serpentine Tube:A Computational Study 认领 引用 被引量：1
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作者 M.Barzegar Gerdroodbary S.Valiallah Mousavi Seyyed Amirreza Abdollahi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第2期624-641,共18页
This study investigates the enhancement of convective heat transfer in a serpentine pipe using ferrofluid flow influenced by dual non-uniform magnetic sources.The primary objective is to improve thermal performance in... This study investigates the enhancement of convective heat transfer in a serpentine pipe using ferrofluid flow influenced by dual non-uniform magnetic sources.The primary objective is to improve thermal performance in compact cooling systems,such as those used in heat exchangers.A two-dimensional,steady-state Computational Fluid Dynamic(CFD)model is developed in ANSYS Fluent to simulate the behavior of an incompressible ferrofluid under applied constant heat flux and magnetic fields.The magnetic force is modeled using the Kelvin force,which acts on magnetized nanoparticles in response to spatially varying electromagnetic fields generated by two strategically positioned current-carrying wires.The effects of magnetic field strength,quantified by the magnetic number(Mn),on flow behavior and temperature distribution are thoroughly analyzed.The results indicate that increasing Mn leads to higher Nusselt numbers,demonstrating enhanced convective heat transfer.Secondary vortices induced by magnetic forcing improve fluid mixing,particularly in curved regions of the pipe.A mesh-independence study and model validation with benchmark data support the reliability of the numerical framework.This work highlights the potential of magnetic-field-assisted thermal control in energy-efficient cooling applications and provides a foundation for the further development of advanced ferrofluid-based heat transfer systems. 展开更多
关键词 Ferrofluid flow heat transfer CFD serpentine pipe heat exchangers
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Three-dimensional heat transfer model of oil-water two-phase stratified flow 认领 引用
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作者 Hui-Shu Liu Ji-Miao Duan +4 位作者 Yong-Xiang Huang Hao-Nan Li Shuo Xu Shi-Ming Chen Hui-Rong Huang 《Petroleum Science》 SCIE EI CAS CSCD 2026年第4期2120-2135,共16页
Oil-water stratified flow,a fundamental pattern in multiphase pipe flow,is commonly encountered in offshore petroleum production and transportation.Although hydraulic characteristics of this flow regime have been exte... Oil-water stratified flow,a fundamental pattern in multiphase pipe flow,is commonly encountered in offshore petroleum production and transportation.Although hydraulic characteristics of this flow regime have been extensively studied,accurate prediction of its heat transfer behavior under nonisothermal conditions remains a challenge.In this study,we develop a three-dimensional heat transfer model for oil-water stratified flow by integrating the energy conservation equation with established flow models and coupling it with momentum conservation.Turbulence is resolved using a lowReynolds-number k-ε model.The phase interface is captured via a minimum energy model,and the irregular physical domain is transformed into a regular rectangular region using bipolar coordinates to simplify grid generation and numerical solution.The model was validated against experimental measurements of average outlet temperatures for both phases,showing relative errors within 5%.Results further reveal how water cut influences the axial temperature distribution and highlight threedimensional temperature profiles during non-isothermal flow.This model provides theoretical insights and practical tools for optimizing thermal management and ensuring safety in offshore petroleum pipeline operations. 展开更多
关键词 Oil-water two-phase flow Stratified flow Heat transfer characteristics Numerical model
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Progress and prospects in sweeping jet heat transfer 认领 引用
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作者 Jingzhou ZHANG Hongren SUI +1 位作者 Chunhua WANG Yong SHAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第4期4-25,共22页
Sweeping Jet Fluidic Oscillator(SJFO)is a functional device to generate self-excited unsteady oscillatory jets,based on the exact nature of flow instabilities within the device.On account of its inherent advantages,su... Sweeping Jet Fluidic Oscillator(SJFO)is a functional device to generate self-excited unsteady oscillatory jets,based on the exact nature of flow instabilities within the device.On account of its inherent advantages,such as unique operation with self-excitation and selfsustainability,strong unsteady flow actuation with high sweep frequency and wide sweep fan angle,simple geometry with no moving parts,etc.,SJFO is recognized as one of the promising potential candidates as applied to flow and heat transfer control practices,particularly for the aerospace community.During the past twenty years,vast efforts have been devoted to this issue,advancing the technological development and innovation application of the SJFOs.The current review mainly concentrates on the emerging interests of SJFOs in heat transfer applications,including sweeping jet impingement heat transfer,sweeping jet film cooling and sweeping jet composite cooling.First,a comprehensive overview regarding the recent advancement of sweeping jet heat transfer is provided.Then,from this overview,some general roles of sweeping jet impingement heat transfer and film cooling are presented and the research gaps are briefly addressed.Finally,an outlook on the challenges and future development of sweeping jet heat transfer is put forward to motivate further investigation in four aspects,such as,actively adjustable strategies for the sweeping jet frequency and fan angle,multi-parameter correlation mechanism and optimization of sweeping jets,integration innovation by combining the other enhanced schemes into sweeping jets,and a wide variety of composite cooling configurations by the use of sweeping jets. 展开更多
关键词 Composite cooling Film cooling Fluidic oscillator Impingement heat transfer Sweeping jet
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Numerical Analysis of Heat Transfer Characteristics in the Thermal-Transfer Printing Head under Pulse Heating Conditions 认领 引用
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作者 Xiufeng Fei Jian Liu +1 位作者 Dianhang Wei Xiaosong Zhang 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期1-15,共15页
Thermal-transfer printing technology has gained widespread adoption in small-format printing devices owing to its fast printing speed,good image quality,and environmental sustainability.However,scaling this technology... Thermal-transfer printing technology has gained widespread adoption in small-format printing devices owing to its fast printing speed,good image quality,and environmental sustainability.However,scaling this technology to large-format printing equipment remains challenging,primarily because the internal heat transfer mechanisms in the large-scale thermal-transfer printing head(TPH)are not yet fully understood.This knowledge gap limits further optimization of device design.A two-dimensional model was established to numerically investigate the internal heat transfer within the thermal-transfer printing head under pulse heating conditions.The simulations reveal that the internal temperature distribution adopts a star-like pattern,driven by the higher thermal conductivity of the bottom film,which accelerates temperature changes.The printing paper effectively filters the heat fluctuation from the heat generator due to its high specific heat capacity and low thermal conductivity.Parametric analysis demonstrates that the temperature of the heat generator reaches a maximum of 428℃ at 70%of pulse width modulation and 500℃ at an amplitude of 5.04 kW.These findings provide a theoretical foundation for optimizing large-scale thermal-transfer printing systems. 展开更多
关键词 Heat transfer thermal-transfer print heat conductivity pulse heat numerical simulation parametric study
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Enhancing microchannel heat transfer using passive vortex generators with a cylinder and staggered flexible beams 认领 引用
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作者 Zhiqiang Xin Zengguo Song Zewen He 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第5期102-116,共15页
A heat transfer system is proposed to enhance the thermal performance of a microchannel by positioning a rigid cylinder upstream of the staggered flexible beams as passive vortex generators.By using a fluid-structure-... A heat transfer system is proposed to enhance the thermal performance of a microchannel by positioning a rigid cylinder upstream of the staggered flexible beams as passive vortex generators.By using a fluid-structure-thermal coupling solver,the effects of the number and spacing of flexible beams on specific physical quantities,such as the local Nusselt number and Colburn factor,were investigated.The results indicate that the periodic pressure variations induced by the wake of the cylinder cause vibrations of the flexible beams,which generate stronger vortices and enhance flow mixing.The staggered flexible beams make vortices closer to the wall,leading to more significant disturbances to the thermal boundary layer and improving convective heat transfer.Further analysis shows that a sufficient number of flexible beams are necessary to effectively perturb the far-field thermal boundary layer due to the dissipation of wake vortices,although this also increases the pressure drop.The spacing of the flexible beams affects the strength of the local vortices,and appropriate spacing increases the intensity of the vortices.By considering both heat transfer performance and energy consumption,the optimal configuration of passive vortex generators is identified in this study. 展开更多
关键词 Fluid-structure-thermal coupling Heat transfer enhancement Vortex generators Flexible beams Thermal boundary layer
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Experimental Study on Heat Transfer Characteristics of New Jacketed Cold Storage Condenser 认领 引用
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作者 Lei Xing Haonan Huang +2 位作者 Mingyang Sun Dongyue Jiang Qiang He 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第1期1-24,共24页
In response to the actual demands of the energy storage type organic Rankine power generation cycle,this study proposes a new type of jacketed shell and tube heat exchanger with integrated cold storage and heat exchan... In response to the actual demands of the energy storage type organic Rankine power generation cycle,this study proposes a new type of jacketed shell and tube heat exchanger with integrated cold storage and heat exchange.N-tedecane is selected as the phase change material for cold storage,low-temperature water as the cold source,and R134a as the heat source.The phase change material for cold storage is filled inside the jacket tube of the heat exchanger.Cold fluid is introduced into the inner tube to cause the phase change material to condense and store cold.After the cold storage is completed,R134a flows in from the shell side and condenses through heat exchange with the solidified phase change material for energy storage.This study discusses the influence laws of different cold water mass flow rates and temperatures on the cold storage performance of this heat exchanger,and analyzes the condensation effect of R134a.The results show that when the mass flow rate is 0.5 kg/s and the cold water temperature is between 3 and 4℃,the average power of the energy storage heat exchanger in the condensation experiment is 80W,and the average convective heat transfer coefficient is 110.73 W/(m2⋅K).This research provides an experimental basis for the development of energy storage organic Rankine power generation cycles. 展开更多
关键词 Phase change cold storage N-tetradecarane shell and tube heat exchanger R134a heat transfer coefficient jacketed type total cold storage capacity cooling power
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Numerical Study on Condensation Flow and Heat Transfer of Hydrocarbon Mixtures in Inclined Tubes under Static and Swaying Conditions 认领 引用
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作者 Xianshi Fang Zexian Guo +1 位作者 Kaihong Tang Guanzhu Ren 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期378-394,共17页
To investigate the complex phase change behavior in two-phase condensation flow of hydrocarbon mixtures in inclined tubes,a numerical model was developed in Fluent using the Volume of Fluid method combined with the Le... To investigate the complex phase change behavior in two-phase condensation flow of hydrocarbon mixtures in inclined tubes,a numerical model was developed in Fluent using the Volume of Fluid method combined with the Lee phase change model.A mixing effect correction was incorporated to enhance the simulation accuracy,and its impact on the flow and heat transfer characteristics was systematically evaluated.Numerical simulations were performed and subsequently corrected for mixing effects;the final results show good agreement with classical experimental data.The average deviation of the heat transfer coefficient is-0.76%,while that of the frictional pressure drop is 4.5%.Furthermore,by introducing the swaying-motion equation into the model,the effects of different swaying periods and amplitudes on the heat transfer under swaying conditions are investigated.The results show that shorter swaying periods and larger swaying amplitudes lead to more pronounced fluctuations in the heat transfer coefficient.Within the parameter range considered in this study,the influence on the time averaged heat transfer coefficient does not exceed 25%.This study provides a solid theoretical and data foundation for the design of relevant condensation heat exchangers,thereby supporting the development of the offshore LNG industry and enhancing energy security. 展开更多
关键词 Hydrocarbon refrigerants condensation heat transfer coefficient frictional pressure drop numerical simulation
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Modeling and Analysis on Flow Instability of Helical Coiled Tube Steam Generator of Liquid Metal Fast Reactor under Coupled Heat Transfer Conditions 认领 引用
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作者 Jialun Liu Yuchang Lu +3 位作者 Jianjun Lin Shebing Li Ruixia Gao Zhao Li 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期178-195,共18页
A steady thermo-hydraulic model of the helical tube steam generator was first constructed to study the coupled heat transfer process between the primary and secondary sides based on a discrete modeling method,and obta... A steady thermo-hydraulic model of the helical tube steam generator was first constructed to study the coupled heat transfer process between the primary and secondary sides based on a discrete modeling method,and obtain the heat flux density distribution along the steam generator.Then,taking the obtained coupled heat flux density distribution as the thermal boundary condition input,considering the dynamic variation of physical properties on the secondary side,a dynamic model based on the time-domain method suitable for two-phase flow instability among parallel multiple channels of the steam generator was constructed.Finally,taking the lead-bismuth fast reactor as an example,flow instability of the steam generator was analyzed under an inlet lead-bismuth temperature of 320℃~480℃ and an inlet water temperature of 160℃~240℃.It was found that flow instability is less likely to occur under coupled heat conditions,compared with that under uniform or linear distribution.Flow excursion is prone to occur under low inlet temperature of the primary or secondary side.As the inlet lead bismuth temperature increases from 320℃ to 480℃,average heat flux significantly increases by 2.5 times,and the non-uniformity of heat flux distribution increases of 49%.Meanwhile,the density wave oscillation amplitude gradually increases,and system stability weakens. 展开更多
关键词 Liquid metal fast reactor helical coiled tube steam generator two-phase flow instability discrete method coupled heat transfer between primary side and second side
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Topology Optimization of Cooling Channels with Conjugate Heat Transfer under Non-Uniform Heat Sources 认领 引用
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作者 Jingjie He Yuhui Jing Xiaopeng Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第4期343-373,共31页
In high-heat-flux environments,traditional cooling channels often fail to satisfy concurrent requirements for high heat transfer efficiency,temperature uniformity,and minimal pumping power.This study proposes an engin... In high-heat-flux environments,traditional cooling channels often fail to satisfy concurrent requirements for high heat transfer efficiency,temperature uniformity,and minimal pumping power.This study proposes an engineering-oriented topology optimization method for fluid-solid conjugate heat transfer to address the conflict between thermal performance and flow resistance under non-uniform heat sources.We introduce a pseudo-threedimensional conjugate heat transfer model governed by Darcy’s law.This formulation retains three-dimensional effects,such as sidewall conduction and non-uniform surface heat flux.Moreover,the governing equations are reduced to two dimensions,thereby significantly enhancing computational efficiency.To resolve the discrepancy between Darcy flow and high-Reynolds-number turbulence,the permeability parameter is calibrated against high-fidelity turbulence simulations,ensuring macroscopic consistency with realistic flow behavior.Using this calibrated model,we perform multi-condition topology optimization for various inlet-outlet configurations under non-uniform heat sources.The optimized designs are reconstructed into three-dimensional geometries and validated via numerical simulations.Compared to conventional straight channel designs,the optimized configurations exhibit better performance,demonstrating reduced peak temperatures,enhanced temperature uniformity,and controlled pressure drops.These findings validate the efficacy of the proposed method for advanced thermal management applications. 展开更多
关键词 Fluid topology optimization conjugate heat transfer pseudo-three-dimensional model non-uniform heat source cooling channel design
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Numerical Simulation of Heat Transfer Enhancement by Vibration of an Irregular Pipe 认领 引用
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作者 Riyi Lin Bi Pang Xinwei Wang 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期16-42,共27页
The thickening of condensed liquid film outside heat-exchange pipes and the pipe bundle effect can significantly degrade the heat transfer efficiency,thus restricting the vacuum phase-change heating furnace from achie... The thickening of condensed liquid film outside heat-exchange pipes and the pipe bundle effect can significantly degrade the heat transfer efficiency,thus restricting the vacuum phase-change heating furnace from achieving its rated thermal efficiency of over 90%.In this work,a heat transfer enhancement method coupling simple harmonic vibration with non-circular pipes was proposed.A CFD model describing the heat transfer process of horizontal pipes under vibratory conditions was established and stepwise validated against experimental data from published literature and the Nusselt analytical solution.Taking a 50 mm steel circular pipe as the reference,numerical simulations were performed to investigate the effects of structural parameters of oval and droplet-shaped pipes on the near-wall velocity,temperature,wall shear stress,and heat transfer coefficient under horizontal simple harmonic vibration.The results demonstrate that simple harmonic vibration can induce oblique cross-flow outside the pipes,enhance flow field disturbance,and disrupt the liquid film stability,thereby providing a crucial flow field regulation mechanism for vibration-enhanced external condensation heat transfer.An increase in the aspect ratio of dropletshaped pipes intensifies the wall contraction effect,promotes the formation of continuous small-scale vortices near the pipe wall,and significantly improves the time-averaged heat transfer coefficient.The heat transfer performance of oval pipes is slightly superior to that of circular pipes;among them,oval pipe 2 achieves a dynamic balance between shear driving force and liquid film resistance through the synergistic matching of velocity,temperature,and viscosity,thus exhibiting the optimal wall shear stress among the oval pipe series.Under dynamic conditions,the time-averaged heat transfer coefficients of non-circular pipes are consistently higher than those of circular pipes.Moreover,the inconsistency between the heat transfer coefficient and wall shear stress distributions reveals the multimechanism synergy characteristics of external condensation heat transfer on non-circular pipes.This study provides core theoretical support for the engineering design of vibration-enhanced heat transfer technologies in vacuum phase-change heating furnaces. 展开更多
关键词 Condensate film harmonic vibration shear force non-circular pipe heat transfer coefficient
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Numerical Study of Heat Transfer Performance of Molten Salt-Based Nanofluid in the Novel Twisted Cloverleaf U-Tube 认领 引用 被引量：1
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作者 Yifan Gui Yuanqiang Duan +3 位作者 Shuo Zhang Yu Huang Minmin Zhou Lunbo Duan 《Engineering》 SCIE EI CSCD 2026年第4期271-286,共16页
Molten salt is widely adopted in diverse thermal energy storage systems owing to its exceptional thermodynamic properties and economical cost.As a critical component in molten salt energy storage systems,the exchanger... Molten salt is widely adopted in diverse thermal energy storage systems owing to its exceptional thermodynamic properties and economical cost.As a critical component in molten salt energy storage systems,the exchangers often utilize U-tube configurations for enhanced compactness,such as shell-and-tube designs.However,the high viscosity and density of molten salt can cause non-uniform flow distribution in U-tubes,posing localized overheating risks.This study proposes a heat transfer enhancement strategy applying a twisted cloverleaf U-tube in combination with molten salt-based nanofluids(MSBNs).The effects of tube geometry,operating parameters,and nanofluid thermophysical properties on flow and thermal performance were analyzed through numerical simulations.Multi-objective optimization of operating conditions was conducted using a combination of response surface method(RSM)and the non-dominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ).Results indicate the twisted structure and nanoparticles significantly enhance heat transfer and improve temperature uniformity,however increase pressure drop.The optimal combination achieved a peak performance evaluation criterion(PEC)value of 1.21.Inlet velocity and inlet temperature influence flow and heat transfer performance additional strongly than heat flux.Optimized operating conditions yield a maximum temperature difference of 40.15 K,pressure drop of 1979.97 Pa,and average convective heat transfer coefficient of 2781.31 W·(m2·K)-1.This work provides critical guidance for the design and operational optimization of novel MSBN heat exchange tubes. 展开更多
关键词 Molten salt-based nanofluid Numerical simulation Heat transfer enhancement Twisted cloverleaf U-tube Multi-objective optimization
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Numerical simulation of multicomponent hydrocarbon flow and heat transfer in a regenerative catalytic oxidizer 认领 引用
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作者 Yujie Kang Guangrun Yang +4 位作者 Jingxiao Wang Zhongjie Shen Jianliang Xu Zhenghua Dai Haifeng Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2026年第1期145-156,共12页
Regenerative catalytic oxidizers(RCO)are widely used to remove volatile organic compounds(VOCs)due to their energy-saving and stability.In this study,a multi-component catalytic reaction model was constructed to numer... Regenerative catalytic oxidizers(RCO)are widely used to remove volatile organic compounds(VOCs)due to their energy-saving and stability.In this study,a multi-component catalytic reaction model was constructed to numerically investigate the reaction process of hydrocarbon-containing VOCs in RCO using computational fluid dynamics(CFD)simulation.To obtain the conversion characteristics of multi-component hydrocarbons,the effects of intake load,equivalence ratio,and the composition of multi-component hydrocarbons on the flow,heat transfer,and conversion rate of the reactor were analyzed.A feasibility study plan targeting the hard-to-convert components was also proposed.The results indicated that as the load increases,the conversion rates of the various components decrease,while the reaction rates increase.Moreover,increasing the flow velocity intensifies turbulence and enhances the collision frequency between the gas and the wall surfaces.This,in turn,amplifies the resistance effect of the porous medium.As the equivalence ratio of VOCs to oxygen increases,the oxygen-deficient condition leads to a decrease in the molecular weight of the hydrocarbons involved in the reaction.The reaction temperature also shows a downward trend.A comparative analysis of the catalytic combustion characteristics of multi-component VOCs and single-component gases reveals that adding ethane and propane can facilitate methane oxidation. 展开更多
关键词 Volatile organic compounds Regenerative catalytic oxidizer Catalysis Numerical simulation Alkane Heat transfer
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Mechanism of Wettability–Rough Morphology Coupling on Convective Heat Transfer in Nanochannels 认领 引用
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作者 Yanfeng Li Xiaohui Zhang +2 位作者 Luyang Chen Rong Chen Shan Qing 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第3期123-140,共18页
Highly integrated micro-nano electronic devices suffer from severe heat dissipation challenges,and flow cooling in nanochannels is an effective solution.During convective heat transfer at liquid-solid interfaces,surfa... Highly integrated micro-nano electronic devices suffer from severe heat dissipation challenges,and flow cooling in nanochannels is an effective solution.During convective heat transfer at liquid-solid interfaces,surface wettability and rough morphology are key parameters governing thermal transport;however,their combined effects remain unclear.In this study,molecular dynamics simulations are utilized to examine the synergistic effects of surface wettability and nanopillar arrays on thermal transport and fluid dynamics within nanochannels.The results show that increasing surface hydrophilicity and roughness reduces the thermal slip length and increases the Nusselt number,thereby enhancing heat transfer performance in the nanochannel.From a fluid dynamics standpoint,velocity slip length decreases while the relative friction coefficient increases,signifying greater flow resistance.For the present model,the enhancement in heat transfer induced by increased wettability is significantly greater than that caused by increased roughness,whereas their effects on flow resistance are difficult to distinguish the dominance.At the microscale,increased wettability and roughness facilitate the accumulation of fluid atoms near the liquid-solid interface.The elevated interaction energy between solid platinum atoms and fluid argon atoms is identified as the primary mechanism underlying thermal transport enhancement in nanochannels.This investigation offers valuable insights for the optimized thermal management of micro-nano electronic devices. 展开更多
关键词 Nanochannel nanopillar arrays heat transfer flow resistance molecular dynamics
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Numerical Simulation of Heat Transfer through Porous Hollow Building Block 认领 引用
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作者 Marina Astanina Igor Miroshnichenko +1 位作者 Gennadii Shashkin Mikhail Sheremet 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期269-287,共19页
This paper explores the thermal behavior of a composite building element consisting of two air cavities inside a porous layer under isothermal heating of the side walls.The system presents a model of a thermal protect... This paper explores the thermal behavior of a composite building element consisting of two air cavities inside a porous layer under isothermal heating of the side walls.The system presents a model of a thermal protection element or building envelope where heat transfer occurs through combined conduction in the porous medium and natural convection in the air gaps.The mathematical formulation is based on the Navier-Stokes equations and the Darcy-Brinkman formulation for the porous structure.The natural convection problem has been solved using theψ-ω-θformulation in dimensionless form(ψ—stream function,ω—vorticity,θ—temperature).The main heat transfer characteristics have been found to be strongly influenced by the governing parameters:Ra(the Rayleigh number),Da(Darcy number),ε(material porosity),and lx,ly(the size of the air gaps).Key findings:increasing the Rayleigh number from 104 to 106 enhances the mean Nusselt number from approximately 0.9 to 3.7 with intensification of convective heat transfer.Variations in the Darcy number over two orders of magnitude(10-4 to 10-2)result in a similar change in the mean Nusselt number.Increasing porosity fromε=0.1 toε=0.8 reduces the Nusselt number by less than 6%.The analysis of air cavity geometry shows that enlarging cavity dimensions increases flow intensity but produces only a moderate enhancement in heat transfer.Practical implications:optimal thermal insulation is achieved with highporosity foam concrete(ε≥0.6)combined with low permeability(Da≤10-4)and minimal air cavity dimensions.In this case,convective circulation is suppressed,and heat transfer remains conduction dominated with minimum values of the mean Nusselt number.The proposed model provides a physically consistent description of thermal transport in hybrid porous/fluid configurations and can serve as a basis for optimizing the thermal design of energy-efficient insulation structures and passive cooling devices. 展开更多
关键词 Hollow building block conjugate heat transfer thermal insulation free convection porous medium Brinkman-extended Darcy model air cavities
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Comparative Study on Flow Heat Transfer Performance of Kelvin Cell and Typical Truss Structures 认领 引用
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作者 Yi Lu Liangliang Liu Haigang Liu 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期255-268,共14页
The Kelvin structure is a regular tetrahedral truss structure similar to the pore structure of metal foam,which is often used to simplify the simulation of metal foam.However,its flow heat transfer characteristics hav... The Kelvin structure is a regular tetrahedral truss structure similar to the pore structure of metal foam,which is often used to simplify the simulation of metal foam.However,its flow heat transfer characteristics have rarely been compared with typical truss structures.To supplement the research work in this aspect and quantify the advantages and disadvantages of these structures compared with typical structures,this paper uses modeling software to create tetrahedrons,BCC truss structures,and Kelvin porous structures with 90%porosity,and uses Fluent to study the distribution rules of temperature,pressure,and velocity of these three structures respectively.The relationship between pressure drop,heat transfer performance,and comprehensive heat transfer performance among different structures and Reynolds number is quantified.The results show that the Kelvin structure has the best heat transfer characteristics,which is 34.6%and 28.9%higher than the tetrahedron and BCC structures,respectively.However,the Kelvin structure has the highest flow resistance,which is 70.7%and 165.3%higher than BCC and tetrahedron structures on average.When the j/f dimensionless calculation criterion is adopted,the comprehensive heat transfer performance of the tetrahedron is 40.5%and 79.8%higher than that of the BCC structure and the Kelvin structure,respectively. 展开更多
关键词 Heat exchanger porous structure flow heat transfer truss structure
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A Review of Artificial Intelligence in Boiling Heat Transfer:Predictive Modeling,Dynamic Characterization,and Methodological Advances 认领 引用
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作者 Wei-Chen Tang Xin Chen Fei Dong 《Fluid Dynamics & Materials Processing》 EI 2026年第4期1-47,共47页
Boiling heat transfer remains a cornerstone of efficient thermal management,with far-reaching implications for energy systems and industrial processes.Advances in this field not only deepen fundamental scientific unde... Boiling heat transfer remains a cornerstone of efficient thermal management,with far-reaching implications for energy systems and industrial processes.Advances in this field not only deepen fundamental scientific understanding but also enable transformative improvements in energy efficiency,equipment performance,and operational safety.Contemporary research in this area focuses on accurate parameter prediction,intelligent image analysis,and quantitative characterization of bubble dynamics,collectively advancing both mechanistic insight and engineering optimization.In this context,artificial intelligence(AI),encompassing machine learning and deep learning techniques,has emerged as a powerful paradigm,offering significant advantages in predictive accuracy,data-driven analysis,and experimental efficiency.This paper provides a systematic review of AI applications in boiling heat transfer research.First,conventional approaches are critically assessed,highlighting the growing relevance and advantages of AI-based methodologies.Next,key machine learning algorithms are introduced and classified according to their roles and capabilities.Subsequently,recent advances in AI-driven prediction of heat transfer parameters,automated analysis of bubble dynamics,and the development of novel research methodologies are comprehensively examined.Finally,current achievements are synthesized,and future research directions are outlined,with particular emphasis on the integration of AI into real-time control and edge-computing frameworks for industrial thermal management. 展开更多
关键词 Artificial intelligence boiling heat transfer bubble dynamics
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Heat Transfer and Flow Transitions of Thermal Plumes Generated by Double Heating Elements in a Confined Enclosure 认领 引用
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作者 WANG Ying XU Zhejian +1 位作者 YANG Wen MA Xinyu 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2026年第1期95-109,共15页
The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to... The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to improve thermal efficiency.In this work,buoyancy-induced flow above two heating elements flush-mounted at the bottom of a square enclosure containing air is numerically investigated over a range of Rayleigh numbers(0<Ra≤1.5×108),with a focus on equal and unequal heat flux conditions under a constraint of constant total thermal energy input.Distinct flow transitions are observed in both cases,leading to the identification of three flow regimes:Steady,periodic unsteady,and chaotic unsteady.Two types of periodic flows are distinguished,in which the first is a periodic flow dominated by a fundamental frequency(FF)and its integer-multiple frequencies(INTMF),while the second is a more complex periodic flow featuring FF,INTMF,and their sub-harmonics.The transitions between these regimes are affected by the relative heat flux of the two heaters.When the heat flux of the two heaters is unequal,the range of Rayleigh numbers corresponding to periodic flow is suppressed.It is also found that the time-averaged maximum temperature of the strong heater increases more rapidly with Ra,while that of the weak heater increases more slowly,reflecting the interaction between buoyancy-driven flow dynamics and asymmetric heat input.Analysis of the time-averaged Nusselt number demonstrates that heat dissipation from the isothermal walls remains roughly equivalent,even when the heat flux of the two heaters differs by a factor of two.These findings highlight the critical roles of Rayleigh number,the number of heaters,and the heat flux ratio of the heaters in determining heat transfer and flow characteristics for buoyancy-driven convection systems,providing important theoretical support and design references for engineering scenarios such as electronic devices and design of new energy systems. 展开更多
关键词 natural convection thermal plume double heating elements flow transitions heat transfer
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Optimizing Hollow Block Roof Design:A Numerical Investigation of Coupled Heat Transfer under Solar Radiation 认领 引用
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作者 Ayoube Baalla Mourad Najjaoui +1 位作者 Thami Ait-Taleb Hassan Chaib 《Fluid Dynamics & Materials Processing》 EI 2026年第7期1-21,共21页
The complex interplay of heat transfer mechanisms,namely conduction,natural convection,and radiation,within hollow block roofs exposed to solar irradiation gives rise to an inherently nonlinear thermal exchange proble... The complex interplay of heat transfer mechanisms,namely conduction,natural convection,and radiation,within hollow block roofs exposed to solar irradiation gives rise to an inherently nonlinear thermal exchange problem.A key yet insufficiently explored question is the extent to which this nonlinearity governs the macroscopic thermal behavior of roofing systems.In this study,a computational investigation is conducted on two roof configurations incorporating five hollow block geometries representative of common construction practices in hot climatic regions.The objective is to identify the optimal design capable of minimizing heat losses and thereby enhancing the overall thermal performance of buildings.The outer roof surfaces are subjected to terrestrial solar radiation and convective exchange with the outdoor environment,whereas the inner surfaces interact with indoor ambient conditions.The governing partial differential equations and associated boundary conditions are discretized using the finite volume method in conjunction with the SIMPLE algorithm.Particular attention is devoted to examining the effects of solar radiation intensity,solid wall thermal conductivity,and cavity aspect ratio on fluid flow characteristics and heat transfer across the roof structures.The results highlight the critical importance of incorporating solar radiation effects into roof design. 展开更多
关键词 Heat transfer computational study solar radiation hollow block thermal conductivity aspect ratio
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Swirl-Induced Flow Instabilities and Heat Transfer Enhancement in Vertical Falling Films at High Reynolds Numbers 认领 引用
19
作者 Lishuang Zheng Fengjun Chen 《Fluid Dynamics & Materials Processing》 EI 2026年第7期100-123,共24页
A computational fluid dynamic(CFD)numerical framework is established in this article to comprehensively uncover the flow evolution laws and gas-liquid phase-change heat transfer mechanisms of vertical falling film wit... A computational fluid dynamic(CFD)numerical framework is established in this article to comprehensively uncover the flow evolution laws and gas-liquid phase-change heat transfer mechanisms of vertical falling film with high Reynolds numbers(Re).Systematic numerical analysis are carried out to characterize the liquid film spatial distribution,flow velocity field,internal turbulent vortex structures and comprehensive heat transfer behaviors.The swirl-induced coherent structures are identified using velocity vectors and vortex-detection criteria,and the influences of swirl angle,channel width,and platform height on film thickness distribution and thermal performance are examined.Model validation is performed through comparison with published numerical and experimental data,showing good agreement.The results indicate that,under high Re conditions,swirling motion significantly disrupts the liquid film and intensifies interfacial turbulence,thereby enhancing heat transfer.The inlet region exhibits the highest thermal performance,driven by strong vortex activity.Increasing the swirl angle leads to a reduction in liquid film thickness and an overall enhancement of heat transfer.However,turbulent kinetic energy and dissipation rate exhibit nonlinear responses to changes in swirl angle.An optimal configuration is identified at a swirl angle of 60°,where the average film thickness is approximately 4.03 mm and interfacial fluctuations remain most stable.In addition,a coupled optimal range is observed for channel width and platform height,highlighting their combined influence on flow stability and thermal efficiency.The underlying two-phase transport mechanisms are interpreted in terms of vortex dynamics and energy transfer processes.Based on the simulation results,a heat transfer correlation valid for high Re conditions is developed.The maximum heat transfer coefficient reaches approximately 700 W/m2·K.Furthermore,fitting of the dimensionless heat transfer coefficient(h+)demonstrates excellent predictive capability for heat transfer trends in gas–liquid two-phase internal flows,with a coefficient of determination(R2)of 0.999. 展开更多
关键词 Swirl falling film fluid dynamic liquid film thickness turbulent flow phase change heat transfer HTC
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Oblique Magneto-Thermal Flow with Non-Fourier Heat Transfer over a Radiative Rotating Disk 认领 引用
20
作者 Abdou Alzubaidi Khalid Mahmud +2 位作者 Rashid Mehmood Siddra Rana Mohammed Alkinidri 《Fluid Dynamics & Materials Processing》 EI 2026年第4期73-90,共18页
Flows over rotating disks are central to numerous engineering applications,including turbines,rotating sensors,and advanced cooling devices,where the incoming fluid often strikes the disk at an angle.This study examin... Flows over rotating disks are central to numerous engineering applications,including turbines,rotating sensors,and advanced cooling devices,where the incoming fluid often strikes the disk at an angle.This study examines magnetohydrodynamic(MHD)oblique slip flow toward a rotating disk,accounting for critical effects such as velocity slip,thermal slip and thermal radiation.In particular,the Cattaneo–Christov heat flux model is used to capture thermal relaxation phenomena,frequently overlooked in prior analyses,while employing a uniform transverse magnetic field to regulate both momentum and heat transfer.Using similarity transformations,the governing nonlinear equations are reduced to ordinary differential equations and solved through a shooting method combined with a robust finite-difference scheme.Three-dimensional streamline visualizations are exploited to elucidate the influence of slip and oblique incidence on the near-disk flow structure.The results reveal three principal effects:the rotational flow intensifies near the disk surface,the stagnation point shifts with velocity slip,and the main-flow velocity increases while cross-flow velocity diminishes as slip rises.Thermal analysis indicates that the boundary-layer temperature decreases under thermal slip and radiation,whereas local heat transfer is significantly enhanced.Furthermore,the skin-friction coefficient grows with disk rotation speed but declines with higher velocity slip,highlighting the coupled influence of rotational and slip effects on overall momentum and heat transfer. 展开更多
关键词 Slip oblique flow rotating disk Cattaneo-Christov:magneto hydrodynamics heat transfer 3Dstreampatterns
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