Applied Thermal Engineering最新文献

Numerical study on the effect of pyrolytic coke deposition of n-decane on flow and heat transfer behavior in porous media 正癸烷热解焦炭沉积对多孔介质流动和传热行为影响的数值研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-05 DOI: 10.1016/j.applthermaleng.2026.130123

Yu Zhang , Shuyuan Liu , Yin Wang , Kaibo Kong , Wenqiang Li

Transpiration cooling method using endothermic hydrocarbon fuels offers high cooling efficiency for hypersonic vehicles but is faced with the challenge of coke deposition in porous media. A two-dimensional transpiration cooling model considering detailed pyrolysis mechanism and coking processes of n-decane is presented in this study. The influence of pyrolytic coke deposition on the porous media properties and transpiration cooling performance is investigated. Under the influence of inflow mainstream at 1600 K for 30 min, the specific coke deposition mass reaches 2.1 μg·cm⁻² in the porous zone. The local porosity and permeability of the porous media decrease by 60% and 91.8%, respectively. Moreover, the flow distribution non-uniformity coefficient of the coolant increases by 28%. Increasing the sintered particle diameter from 50 μm to 150 μm results in a decrease by 80% in local coke deposition and a decrease by 16.6% in the flow non-uniformity coefficient. Moreover, heat transfer in the boundary layer exhibits opposite variation trends with time for the proximal and the distal ends of the outlet surface of the porous media due to coking-induced coolant migration. The mechanistic analysis shows that the effect of particle diameter on coking rate is initially dominated by the permeability-induced temperature difference but then dominated by the increasing difference in coolant residence time as coking process becomes significant. Specifically, coking rate is more sensitive to local temperature and flow residence time when very small sintered particles are used. For coking time of 30 min, the average cooling efficiency with the sintered diameter of 50 μm and 150 μm decreases by 5% and 2%, respectively. The research findings contribute to a deeper understanding of the impact of pyrolytic coke deposition on flow and heat transfer behaviors in the transpiration cooling process using hydrocarbon coolants.

{"title":"Numerical study on the effect of pyrolytic coke deposition of n-decane on flow and heat transfer behavior in porous media","authors":"Yu Zhang , Shuyuan Liu , Yin Wang , Kaibo Kong , Wenqiang Li","doi":"10.1016/j.applthermaleng.2026.130123","DOIUrl":"10.1016/j.applthermaleng.2026.130123","url":null,"abstract":"<div><div>Transpiration cooling method using endothermic hydrocarbon fuels offers high cooling efficiency for hypersonic vehicles but is faced with the challenge of coke deposition in porous media. A two-dimensional transpiration cooling model considering detailed pyrolysis mechanism and coking processes of n-decane is presented in this study. The influence of pyrolytic coke deposition on the porous media properties and transpiration cooling performance is investigated. Under the influence of inflow mainstream at 1600 K for 30 min, the specific coke deposition mass reaches 2.1 μg·cm<sup>−2</sup> in the porous zone. The local porosity and permeability of the porous media decrease by 60% and 91.8%, respectively. Moreover, the flow distribution non-uniformity coefficient of the coolant increases by 28%. Increasing the sintered particle diameter from 50 μm to 150 μm results in a decrease by 80% in local coke deposition and a decrease by 16.6% in the flow non-uniformity coefficient. Moreover, heat transfer in the boundary layer exhibits opposite variation trends with time for the proximal and the distal ends of the outlet surface of the porous media due to coking-induced coolant migration. The mechanistic analysis shows that the effect of particle diameter on coking rate is initially dominated by the permeability-induced temperature difference but then dominated by the increasing difference in coolant residence time as coking process becomes significant. Specifically, coking rate is more sensitive to local temperature and flow residence time when very small sintered particles are used. For coking time of 30 min, the average cooling efficiency with the sintered diameter of 50 μm and 150 μm decreases by 5% and 2%, respectively. The research findings contribute to a deeper understanding of the impact of pyrolytic coke deposition on flow and heat transfer behaviors in the transpiration cooling process using hydrocarbon coolants.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130123"},"PeriodicalIF":6.9,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advanced polyethylene glycol based flexible composite phase change materials enabling stable and efficient lithium-ion battery thermal safety management 先进的聚乙二醇基柔性复合相变材料，实现稳定高效的锂离子电池热安全管理

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-05 DOI: 10.1016/j.applthermaleng.2026.130112

Adili Aliya , Yan Gong , Yin Chen , Ruichao Wei , Mingyi Chen

Rapid economic development has led to a significant increase in the demand for new energy across countries. Due to their high energy density and long cycle life, lithium-ion batteries are widely used in new-energy vehicles and renewable energy storage systems. However, lithium-ion batteries exhibit significant sensitivity to temperature fluctuations, highlighting the necessity of effective and energy-efficient thermal management. Phase change materials (PCMs) offer a promising passive cooling solution but are hindered by inherent drawbacks such as low thermal conductivity and leakage, which significantly limit their application in thermal management. In this study, a novel flexible composite phase change material (FCPCMs) is developed, which utilizes polyethylene glycol as the phase change core. It is effectively encapsulated and supported by a rigid matrix of styrene-ethylene-propylene-styrene block copolymer and the flexibility of polyolefin elastomer, which confers excellent form stability. Furthermore, a ternary thermally conductive network comprising expanded graphite, carbon nanotubes, and copper powder is incorporated, dramatically enhancing the thermal conductivity of the FCPCM to 1.47 W/m K, with an increase of 374%. The FCPCMs reduce the peak battery temperature by up to 19.1 °C (corresponding to a 26.6% decrease from the natural air-cooling baseline of 71.7 °C) and the maximum temperature difference by up to 78.43%. This work provides an effective material strategy for developing high-performance, leakage-resistant PCMs for enhanced battery safety and longevity.

{"title":"Advanced polyethylene glycol based flexible composite phase change materials enabling stable and efficient lithium-ion battery thermal safety management","authors":"Adili Aliya , Yan Gong , Yin Chen , Ruichao Wei , Mingyi Chen","doi":"10.1016/j.applthermaleng.2026.130112","DOIUrl":"10.1016/j.applthermaleng.2026.130112","url":null,"abstract":"<div><div>Rapid economic development has led to a significant increase in the demand for new energy across countries. Due to their high energy density and long cycle life, lithium-ion batteries are widely used in new-energy vehicles and renewable energy storage systems. However, lithium-ion batteries exhibit significant sensitivity to temperature fluctuations, highlighting the necessity of effective and energy-efficient thermal management. Phase change materials (PCMs) offer a promising passive cooling solution but are hindered by inherent drawbacks such as low thermal conductivity and leakage, which significantly limit their application in thermal management. In this study, a novel flexible composite phase change material (FCPCMs) is developed, which utilizes polyethylene glycol as the phase change core. It is effectively encapsulated and supported by a rigid matrix of styrene-ethylene-propylene-styrene block copolymer and the flexibility of polyolefin elastomer, which confers excellent form stability. Furthermore, a ternary thermally conductive network comprising expanded graphite, carbon nanotubes, and copper powder is incorporated, dramatically enhancing the thermal conductivity of the FCPCM to 1.47 W/m K, with an increase of 374%. The FCPCMs reduce the peak battery temperature by up to 19.1 °C (corresponding to a 26.6% decrease from the natural air-cooling baseline of 71.7 °C) and the maximum temperature difference by up to 78.43%. This work provides an effective material strategy for developing high-performance, leakage-resistant PCMs for enhanced battery safety and longevity.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130112"},"PeriodicalIF":6.9,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Energy and exergy analysis of gas-solid heat transfer in double-stage cooling device for sinter waste heat recovery 烧结余热回收双级冷却装置气固传热能量及火用分析

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-04 DOI: 10.1016/j.applthermaleng.2026.130119

Yuming Jiao , Junsheng Feng , Liang Zhao , Hui Dong , Wenhao Jiang

To overcome the intrinsic limitations of conventional sinter waste heat recovery (WHR) systems, the present study proposes a novel double stage cooling device (DSCD) integrating vertical cooling with annular re-cooling. Based on porous media theory and non-equilibrium dual-energy equations, comprehensive models describing the flow and heat transfer processes within the DSCD were developed. And then, the effects of inlet air flow rate and temperature, as well as the height and length of cooling section on the key performance indicators in the DSCD were studied. Furthermore, a dual-objective optimization model was applied to determine the optimal structural and operational parameters of the DSCD. The results demonstrate that the WHR rate shows a gradual reducing trend with the rise of inlet air temperature, and the larger the inlet air flow rate, the height and length of cooling section are, the greater the WHR rate is. The exergy destruction of heat carrier in the DSCD presents a gradual increase with the rise of inlet air flow rate and cooling section height, and gradually reduces as the inlet air temperature and cooling section length rise. Under the optimal condition, the suitable parameter combination in the DSCD is the inlet air flow rate of 170 kg/s, the inlet air temperature of 333 K, the cooling section height of 7.5 m, and the cooling section length of 10 m. Based on the above optimal parameters, the WHR efficiency of DSCD can reach 77.3%, showing a better WHR effect.

{"title":"Energy and exergy analysis of gas-solid heat transfer in double-stage cooling device for sinter waste heat recovery","authors":"Yuming Jiao , Junsheng Feng , Liang Zhao , Hui Dong , Wenhao Jiang","doi":"10.1016/j.applthermaleng.2026.130119","DOIUrl":"10.1016/j.applthermaleng.2026.130119","url":null,"abstract":"<div><div>To overcome the intrinsic limitations of conventional sinter waste heat recovery (WHR) systems, the present study proposes a novel double stage cooling device (DSCD) integrating vertical cooling with annular re-cooling. Based on porous media theory and non-equilibrium dual-energy equations, comprehensive models describing the flow and heat transfer processes within the DSCD were developed. And then, the effects of inlet air flow rate and temperature, as well as the height and length of cooling section on the key performance indicators in the DSCD were studied. Furthermore, a dual-objective optimization model was applied to determine the optimal structural and operational parameters of the DSCD. The results demonstrate that the WHR rate shows a gradual reducing trend with the rise of inlet air temperature, and the larger the inlet air flow rate, the height and length of cooling section are, the greater the WHR rate is. The exergy destruction of heat carrier in the DSCD presents a gradual increase with the rise of inlet air flow rate and cooling section height, and gradually reduces as the inlet air temperature and cooling section length rise. Under the optimal condition, the suitable parameter combination in the DSCD is the inlet air flow rate of 170 kg/s, the inlet air temperature of 333 K, the cooling section height of 7.5 m, and the cooling section length of 10 m. Based on the above optimal parameters, the WHR efficiency of DSCD can reach 77.3%, showing a better WHR effect.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130119"},"PeriodicalIF":6.9,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A numerical model for AP/HTPB premixed combustion AP/HTPB预混燃烧数值模型

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-04 DOI: 10.1016/j.applthermaleng.2026.130106

Neeraj Kumar Pradhan , Arindrajit Chowdhury , Debasis Chakraborty , Neeraj Kumbhakarna

A simulation model is developed for the premixed combustion of Ammonium Perchlorate (AP) and Hydroxyl-terminated Polybutadiene (HTPB) using a detailed chemical mechanism in gas and semiglobal kinetics in condensed phases. The suggested model considers the burning of the premixed propellant in three distinct phases: a solid phase, a condensed phase region consisting of liquid, and a premixed gas phase flame. This model uses the full chemical mechanism for the gas phase, with 37 species, 127 reactions, and six reactions in the condensed phase. Energy, species, and mass conservation are considered in condensed phases, while gas phase dynamics are simulated using the ChemKin premix code. The model's validation includes comparing experimental burn rates of propellant configurations with 80% and 82% AP, and major and minor species mole fraction data available in the literature. The model precisely characterises the relationship between burn rate and pressure data within the range of low to moderate pressures. The computed species mole fractions agree well with experimental data and equilibrium values. Insights into flame dynamics are obtained by analysing the nature of combustion, surface temperature, melt temperature and heat flux. Promising results led to further parametric investigations into various AP weight fractions for premix combustion cases. A preliminary model discussed in this paper is essential before developing a more comprehensive model that considers multi-modal composite propellants with larger AP grains and the related diffusion flame.

{"title":"A numerical model for AP/HTPB premixed combustion","authors":"Neeraj Kumar Pradhan , Arindrajit Chowdhury , Debasis Chakraborty , Neeraj Kumbhakarna","doi":"10.1016/j.applthermaleng.2026.130106","DOIUrl":"10.1016/j.applthermaleng.2026.130106","url":null,"abstract":"<div><div>A simulation model is developed for the premixed combustion of Ammonium Perchlorate (AP) and Hydroxyl-terminated Polybutadiene (HTPB) using a detailed chemical mechanism in gas and semiglobal kinetics in condensed phases. The suggested model considers the burning of the premixed propellant in three distinct phases: a solid phase, a condensed phase region consisting of liquid, and a premixed gas phase flame. This model uses the full chemical mechanism for the gas phase, with 37 species, 127 reactions, and six reactions in the condensed phase. Energy, species, and mass conservation are considered in condensed phases, while gas phase dynamics are simulated using the ChemKin premix code. The model's validation includes comparing experimental burn rates of propellant configurations with 80% and 82% AP, and major and minor species mole fraction data available in the literature. The model precisely characterises the relationship between burn rate and pressure data within the range of low to moderate pressures. The computed species mole fractions agree well with experimental data and equilibrium values. Insights into flame dynamics are obtained by analysing the nature of combustion, surface temperature, melt temperature and heat flux. Promising results led to further parametric investigations into various AP weight fractions for premix combustion cases. A preliminary model discussed in this paper is essential before developing a more comprehensive model that considers multi-modal composite propellants with larger AP grains and the related diffusion flame.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130106"},"PeriodicalIF":6.9,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Programmable interfacial Nanofluids for high-heat-flux Chip cooling via heat networks 高热流通量芯片通过热网冷却的可编程界面纳米流体

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-04 DOI: 10.1016/j.applthermaleng.2026.130142

Chenghang Li , Zhumei Luo , Shan Qing , Xiaohui Zhang , Zichang Shi , Guili He , Shuai Feng , Haoming Huang , Xiaoyu Huang , Jing Zhang

To overcome thermal bottlenecks in high–heat-flux chip cooling, we develop a programmable interfacial nanofluid (CuO@APTES/L-cysteine/SSA) through surface molecular engineering integrated with a multiscale framework spanning material synthesis, density functional theory (DFT), molecular dynamics (MD), microchannel experiments, and computational fluid dynamics (CFD) validation. DFT calculations confirm robust interfacial stability enabled by Si–O–Cu anchoring, yielding a total binding energy of −33.48 eV. Spectroscopic and microscopic characterizations verify ordered multilayer functionalization, defining a grafting maximum load (GML) of 174.97% and excellent dispersion stability (zeta potential up to +59 mV).

At 358.15 K and 2.5 vol%, the nanofluid achieves a thermal conductivity of 1.517 W/m·K (138.5% enhancement over water), significantly exceeding Maxwell predictions, with the optimized S30.4 formulation reaching 1.79 W/m·K. Molecular-level analysis reveals a transition from passive to programmable interfacial heat transport, characterized by enhanced CuO radial distribution functions, increased coordination numbers, and strengthened SiO and OS heat-transfer pathways.

Microchannel experiments demonstrate a 14.7% reduction in junction temperature and a 17.3% improvement in temperature uniformity at 10 W/cm², accompanied by reduced thermal resistance and improved convective heat transfer. CFD predictions agree well with experiments (deviation <1.5%) and confirm superior cooling performance up to 10,000 W/cm² with only a modest pressure-drop penalty. Thereby establishing a validated multiscale framework that provides predictive insight into interfacial heat transport and guides the design of advanced nanofluids for high–heat-flux electronic cooling.

{"title":"Programmable interfacial Nanofluids for high-heat-flux Chip cooling via heat networks","authors":"Chenghang Li , Zhumei Luo , Shan Qing , Xiaohui Zhang , Zichang Shi , Guili He , Shuai Feng , Haoming Huang , Xiaoyu Huang , Jing Zhang","doi":"10.1016/j.applthermaleng.2026.130142","DOIUrl":"10.1016/j.applthermaleng.2026.130142","url":null,"abstract":"<div><div>To overcome thermal bottlenecks in high–heat-flux chip cooling, we develop a programmable interfacial nanofluid (CuO@APTES/L-cysteine/SSA) through surface molecular engineering integrated with a multiscale framework spanning material synthesis, density functional theory (DFT), molecular dynamics (MD), microchannel experiments, and computational fluid dynamics (CFD) validation. DFT calculations confirm robust interfacial stability enabled by Si–O–Cu anchoring, yielding a total binding energy of −33.48 eV. Spectroscopic and microscopic characterizations verify ordered multilayer functionalization, defining a grafting maximum load (GML) of 174.97% and excellent dispersion stability (zeta potential up to +59 mV).</div><div>At 358.15 K and 2.5 vol%, the nanofluid achieves a thermal conductivity of 1.517 W/m·K (138.5% enhancement over water), significantly exceeding Maxwell predictions, with the optimized S30.4 formulation reaching 1.79 W/m·K. Molecular-level analysis reveals a transition from passive to programmable interfacial heat transport, characterized by enhanced Cu<img>O radial distribution functions, increased coordination numbers, and strengthened Si<img>O and O<img>S heat-transfer pathways.</div><div>Microchannel experiments demonstrate a 14.7% reduction in junction temperature and a 17.3% improvement in temperature uniformity at 10 W/cm<sup>2</sup>, accompanied by reduced thermal resistance and improved convective heat transfer. CFD predictions agree well with experiments (deviation <1.5%) and confirm superior cooling performance up to 10,000 W/cm<sup>2</sup> with only a modest pressure-drop penalty. Thereby establishing a validated multiscale framework that provides predictive insight into interfacial heat transport and guides the design of advanced nanofluids for high–heat-flux electronic cooling.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130142"},"PeriodicalIF":6.9,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Three-dimensional layer-level model of cylindrical lithium-ion batteries 圆柱形锂离子电池的三维层级模型

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-03 DOI: 10.1016/j.applthermaleng.2026.130124

Junghyun Nam, Seunghun Jung

The shift toward large-format cylindrical lithium-ion batteries necessitates precise modeling of electro-thermal non-uniformity. However, conventional distributed equivalent circuit models (Distributed ECMs) oversimplify the spiral-wound structure as a homogeneous layer, neglecting the critical coupling between through-plane ionic transport and in-plane electronic conduction. To address this, we propose a three-dimensional layer-level overlapped potential-pair network (OPPN) framework. This electro-thermal model, implemented using the finite volume method, physically reconstructs the bipolar connectivity through the jellyroll thickness. Validation against Panasonic NCR18650B experiments confirmed high predictive accuracy. Crucially, comparative analysis reveals that the Distributed ECM fundamentally miscalculates internal current distribution. Specifically, while the Distributed ECM predicted negligible variations across tab configurations (potential drop <0.001 V, temperature difference < 0.4 °C), the layer-level OPPN model captured significant structure-induced gradients, revealing potential drops and temperature deviations up to 0.04 V and 1.7 °C, respectively. This confirms that Distributed ECMs predict unrealistic uniformity in State-of-Charge (SOC) and temperature fields. Since overlooking these gradients poses severe risks for thermal design and lifetime estimation, this study establishes the OPPN framework as an essential engineering tool for the robust design of modern, scaling cylindrical batteries.

{"title":"Three-dimensional layer-level model of cylindrical lithium-ion batteries","authors":"Junghyun Nam, Seunghun Jung","doi":"10.1016/j.applthermaleng.2026.130124","DOIUrl":"10.1016/j.applthermaleng.2026.130124","url":null,"abstract":"<div><div>The shift toward large-format cylindrical lithium-ion batteries necessitates precise modeling of electro-thermal non-uniformity. However, conventional distributed equivalent circuit models (Distributed ECMs) oversimplify the spiral-wound structure as a homogeneous layer, neglecting the critical coupling between through-plane ionic transport and in-plane electronic conduction. To address this, we propose a three-dimensional layer-level overlapped potential-pair network (OPPN) framework. This electro-thermal model, implemented using the finite volume method, physically reconstructs the bipolar connectivity through the jellyroll thickness. Validation against Panasonic NCR18650B experiments confirmed high predictive accuracy. Crucially, comparative analysis reveals that the Distributed ECM fundamentally miscalculates internal current distribution. Specifically, while the Distributed ECM predicted negligible variations across tab configurations (potential drop <0.001 V, temperature difference < 0.4 °C), the layer-level OPPN model captured significant structure-induced gradients, revealing potential drops and temperature deviations up to 0.04 V and 1.7 °C, respectively. This confirms that Distributed ECMs predict unrealistic uniformity in State-of-Charge (SOC) and temperature fields. Since overlooking these gradients poses severe risks for thermal design and lifetime estimation, this study establishes the OPPN framework as an essential engineering tool for the robust design of modern, scaling cylindrical batteries.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130124"},"PeriodicalIF":6.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal analysis of a solar-assisted pyrolysis drop tube reactor with radiation heat transfer 太阳辅助热解落管反应器辐射传热的热分析

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-03 DOI: 10.1016/j.applthermaleng.2026.130033

Amir Hossein Bashiri , Shervin Karimkashi , Vignesvar Krish Subramani , Sylvain Rodat , Stéphane Abanades , Mika Järvinen , Ville Vuorinen

Fast pyrolysis of biomass is recognized as a promising method for bio-oil production which can be further utilized in the production of sustainable fuels. Numerical simulations are carried out in order to verify the discrete ordinate method (DOM) implementation in OpenFOAM open-source software. 1D and 3D test problems are investigated including conjugate and radiative heat transfer in addition to a 2D test case. The main application of interest is a 3D solar-assisted drop tube reactor, which is studied from the viewpoint of heat distribution within the reactor. The main results of the research are as follows: (1) 1D modeling indicates that the heat fluxes are correctly implemented for transient and steady state configurations. (2) 2D rectangular enclosure study indicate correct heat flux implementation in OpenFOAM for the viewFactor and fvDOM methods. (3) 3D reactor studies in OpenFOAM and STAR-CCM+ indicate that the heat distributions are highly similar within 2% deviation in peak temperature values. The final 3D results are noted to be grid independent and independent on the angular discretization number when

N_{ϕ} \geq 16

. As a conclusion, the validated/verified numerical approach offers a general open-source framework for coupled CHT-radiation problems with applicability beyond the studied drop tube reactor.

{"title":"Thermal analysis of a solar-assisted pyrolysis drop tube reactor with radiation heat transfer","authors":"Amir Hossein Bashiri , Shervin Karimkashi , Vignesvar Krish Subramani , Sylvain Rodat , Stéphane Abanades , Mika Järvinen , Ville Vuorinen","doi":"10.1016/j.applthermaleng.2026.130033","DOIUrl":"10.1016/j.applthermaleng.2026.130033","url":null,"abstract":"<div><div>Fast pyrolysis of biomass is recognized as a promising method for bio-oil production which can be further utilized in the production of sustainable fuels. Numerical simulations are carried out in order to verify the discrete ordinate method (DOM) implementation in OpenFOAM open-source software. 1D and 3D test problems are investigated including conjugate and radiative heat transfer in addition to a 2D test case. The main application of interest is a 3D solar-assisted drop tube reactor, which is studied from the viewpoint of heat distribution within the reactor. The main results of the research are as follows: (1) 1D modeling indicates that the heat fluxes are correctly implemented for transient and steady state configurations. (2) 2D rectangular enclosure study indicate correct heat flux implementation in OpenFOAM for the <span>viewFactor</span> and <span>fvDOM</span> methods. (3) 3D reactor studies in OpenFOAM and STAR-CCM+ indicate that the heat distributions are highly similar within 2% deviation in peak temperature values. The final 3D results are noted to be grid independent and independent on the angular discretization number when <span><math><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>ϕ</mi></mrow></msub><mo>≥</mo><mn>16</mn></mrow></math></span>. As a conclusion, the validated/verified numerical approach offers a general open-source framework for coupled CHT-radiation problems with applicability beyond the studied drop tube reactor.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130033"},"PeriodicalIF":6.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advanced exergy analysis of Rankine-based pumped thermal energy storage systems: Methodology and theoretical analysis 基于朗肯抽水蓄能系统的先进火用分析：方法和理论分析

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-02 DOI: 10.1016/j.applthermaleng.2026.129892

Sergio Tomasinelli , Mathias Hofmann , Francesco Witte , George Tsatsaronis

Large-scale electricity storage is crucial for balancing renewable energy supply and demand. Pumped thermal energy storage (PTES) systems present a promising solution by converting electrical energy to thermal energy for storage and subsequent reconversion to electricity. This study contributes to the advancement of PTES technology through two primary contributions. Firstly, it presents a novel methodology for advanced exergy analysis that integrates the rigor of the decomposition method with cycle-based simulation approaches. Secondly, it employs this methodology to analyze different PTES configurations, facilitating a comparative analysis of systems with pressurized and atmospheric thermal energy storage across varying temperature levels. The methodology is implemented in a dedicated Python code that solves all real, ideal, and hybrid cases within a unified Newton–Raphson framework. This code is distributed together with the PTES models and input data. The findings indicate that, while heat exchangers exhibit the highest exergy destruction rates, turbomachinery components offer greater potential for optimization. The high-temperature PTES configuration achieves superior round-trip efficiency (up to 43.2%) in comparison to the low-temperature design (below 40%). The results of this study indicate that open-source frameworks can support the conduction of comprehensive exergy analyses, thereby establishing a foundation for future research endeavors aimed at incorporating economic considerations and more complex process designs.

{"title":"Advanced exergy analysis of Rankine-based pumped thermal energy storage systems: Methodology and theoretical analysis","authors":"Sergio Tomasinelli , Mathias Hofmann , Francesco Witte , George Tsatsaronis","doi":"10.1016/j.applthermaleng.2026.129892","DOIUrl":"10.1016/j.applthermaleng.2026.129892","url":null,"abstract":"<div><div>Large-scale electricity storage is crucial for balancing renewable energy supply and demand. Pumped thermal energy storage (PTES) systems present a promising solution by converting electrical energy to thermal energy for storage and subsequent reconversion to electricity. This study contributes to the advancement of PTES technology through two primary contributions. Firstly, it presents a novel methodology for advanced exergy analysis that integrates the rigor of the decomposition method with cycle-based simulation approaches. Secondly, it employs this methodology to analyze different PTES configurations, facilitating a comparative analysis of systems with pressurized and atmospheric thermal energy storage across varying temperature levels. The methodology is implemented in a dedicated Python code that solves all real, ideal, and hybrid cases within a unified Newton–Raphson framework. This code is distributed together with the PTES models and input data. The findings indicate that, while heat exchangers exhibit the highest exergy destruction rates, turbomachinery components offer greater potential for optimization. The high-temperature PTES configuration achieves superior round-trip efficiency (up to 43.2%) in comparison to the low-temperature design (below 40%). The results of this study indicate that open-source frameworks can support the conduction of comprehensive exergy analyses, thereby establishing a foundation for future research endeavors aimed at incorporating economic considerations and more complex process designs.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 129892"},"PeriodicalIF":6.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on multi-cylinder pre-ignition characteristics and pre-ignition induced super knock mechanism of direct injected hydrogen engines 直喷氢发动机多缸预燃特性及预燃诱发超爆震机理研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-02-02 DOI: 10.1016/j.applthermaleng.2026.130092

Yong-hui Duan , Qing-he Luo , Shi-wei Zhang , Bai-gang Sun , Ling-zhi Bao , Shan-feng Li , Jia-xian Zhang , Yu Bu

Hydrogen internal combustion engines (HICEs) are a promising near-term route to low-carbon energy propulsion; however, abnormal combustion continues to constrain their reliable operation. Among these anomalous phenomena, pre-ignition (PI) represents a major barrier to the performance and durability of direct-injection HICEs (DI-HICEs), while its multi-cylinder behavior under high-load and high-speed conditions remains insufficiently understood. In this study, PI characteristics are experimentally investigated on a 1.5 L turbocharged DI-HICE operated at a high load corresponding to a brake mean effective pressure (BMEP) of 1.4 MPa and engine speeds of 2500 and 5500 rpm, with injection timings of 120 °CA and 160 °CA before top dead center, respectively. A robust identification method based on the median method of the 5% mass fraction burnt is employed. Seven distinct PI occurrence modes are identified, capturing both cylinder-specific behavior and cross-cylinder interactions. At 2500 rpm, obvious PI takes up 84.7% of total 62 PI cycles, while the maximum amplitude of pressure oscillations (MAPO) remains below 0.16 MPa. In contrast, at 5500 rpm, a limited number of PI cycles are associated with high-intensity knock, with a MAPO exceeding 4 MPa. Furthermore, a dimensionless mechanistic analysis shows that low-speed (2500 rpm) PI, characterized by strong energy dissipation relative to chemical energy release, remains confined to non-knock and conventional-knock regions within the detonation peninsula, accompanied by sub-supersonic pressure development. Contrary to the gasoline engines, where the dwell time for PI to occur is reduced with higher engine speed, this effect is insufficient to offset the extremely short ignition delay of hydrogen at high speeds. As a result, at 5500 rpm, elevated hot-spot reactivity combined with rapid hydrogen chemistry is associated with a shift of PI events toward high-intensity knock regimes. These findings systematize PI occurrence modes, speed-dependent characteristics under high load, and provide a phenomenological interpretation of PI–knock coupling in DI-HICEs, offering practical insights for improving the efficiency and reliability of hydrogen engine operation.

{"title":"Study on multi-cylinder pre-ignition characteristics and pre-ignition induced super knock mechanism of direct injected hydrogen engines","authors":"Yong-hui Duan , Qing-he Luo , Shi-wei Zhang , Bai-gang Sun , Ling-zhi Bao , Shan-feng Li , Jia-xian Zhang , Yu Bu","doi":"10.1016/j.applthermaleng.2026.130092","DOIUrl":"10.1016/j.applthermaleng.2026.130092","url":null,"abstract":"<div><div>Hydrogen internal combustion engines (HICEs) are a promising near-term route to low-carbon energy propulsion; however, abnormal combustion continues to constrain their reliable operation. Among these anomalous phenomena, pre-ignition (PI) represents a major barrier to the performance and durability of direct-injection HICEs (DI-HICEs), while its multi-cylinder behavior under high-load and high-speed conditions remains insufficiently understood. In this study, PI characteristics are experimentally investigated on a 1.5 L turbocharged DI-HICE operated at a high load corresponding to a brake mean effective pressure (BMEP) of 1.4 MPa and engine speeds of 2500 and 5500 rpm, with injection timings of 120 °CA and 160 °CA before top dead center, respectively. A robust identification method based on the median method of the 5% mass fraction burnt is employed. Seven distinct PI occurrence modes are identified, capturing both cylinder-specific behavior and cross-cylinder interactions. At 2500 rpm, obvious PI takes up 84.7% of total 62 PI cycles, while the maximum amplitude of pressure oscillations (MAPO) remains below 0.16 MPa. In contrast, at 5500 rpm, a limited number of PI cycles are associated with high-intensity knock, with a MAPO exceeding 4 MPa. Furthermore, a dimensionless mechanistic analysis shows that low-speed (2500 rpm) PI, characterized by strong energy dissipation relative to chemical energy release, remains confined to non-knock and conventional-knock regions within the detonation peninsula, accompanied by sub-supersonic pressure development. Contrary to the gasoline engines, where the dwell time for PI to occur is reduced with higher engine speed, this effect is insufficient to offset the extremely short ignition delay of hydrogen at high speeds. As a result, at 5500 rpm, elevated hot-spot reactivity combined with rapid hydrogen chemistry is associated with a shift of PI events toward high-intensity knock regimes. These findings systematize PI occurrence modes, speed-dependent characteristics under high load, and provide a phenomenological interpretation of PI–knock coupling in DI-HICEs, offering practical insights for improving the efficiency and reliability of hydrogen engine operation.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 130092"},"PeriodicalIF":6.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development and optimization of a 100 Hz lightweight pulse tube cryocooler achieving 9.76 W at 60 K for space applications 开发和优化100 Hz轻型脉冲管制冷机，在60 K时实现9.76 W的空间应用

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-01-31 DOI: 10.1016/j.applthermaleng.2026.129977

Enchun Xing , Xuelian Sun , Hongyan Wei , Zhi Zhang , Huaqiang Zhong , Jinghui Cai

To meet the pressing need for lightweight and efficient cryogenic cooling in space-based long-wave infrared detection, this study addresses the performance degradation of the cold finger in 60 K pulse tube cryocoolers (PTCs) under high-frequency operation for system mass reduction. Using a combined approach of numerical simulation and experimental validation, the geometry of the regenerator—a key component of the cold finger—and its graded stainless-steel wire-mesh packing strategy were systematically optimized, while the influence of operating parameters on cryocooler performance was analyzed. An integrated high-frequency prototype was subsequently developed.Experimental results demonstrate that with an input power of 250 W, a charging pressure of 6 MPa, and an operating frequency of 100 Hz, the 4.4 kg cryocooler achieves a no-load temperature of 29.75 K and delivers a cooling capacity of 9.76 W at 60 K, corresponding to a relative Carnot efficiency of 15.6%. When the input power is increased to 300 W, the system provides 3.8 W of cooling capacity at 40 K and 11.5 W at 60 K.The study further reveals the shift in the optimal operating frequency across different temperature zones and confirms the coupled governing mechanism of system efficiency, which is jointly determined by compressor efficiency and cold-finger efficiency.

为了满足天基长波红外探测对轻量化、高效低温冷却的迫切需求，本研究针对60k脉冲管制冷机（ptc）中冷手指在高频工作下的性能退化问题进行了研究，以减少系统质量。采用数值模拟与实验验证相结合的方法，系统优化了冷指关键部件蓄热器的几何形状及其分级不锈钢丝网填料策略，分析了操作参数对制冷机性能的影响。随后开发了集成高频样机。实验结果表明，在输入功率为250 W、充注压力为6 MPa、工作频率为100 Hz的条件下，4.4 kg的制冷机空载温度为29.75 K，在60 K时制冷量为9.76 W，相对卡诺效率为15.6%。当输入功率增加到300w时，系统在40k时可提供3.8 W的制冷量，在60k时可提供11.5 W的制冷量。研究进一步揭示了最佳工作频率在不同温区之间的变化，并确定了由压缩机效率和冷指效率共同决定的系统效率耦合调控机制。

{"title":"Development and optimization of a 100 Hz lightweight pulse tube cryocooler achieving 9.76 W at 60 K for space applications","authors":"Enchun Xing , Xuelian Sun , Hongyan Wei , Zhi Zhang , Huaqiang Zhong , Jinghui Cai","doi":"10.1016/j.applthermaleng.2026.129977","DOIUrl":"10.1016/j.applthermaleng.2026.129977","url":null,"abstract":"<div><div>To meet the pressing need for lightweight and efficient cryogenic cooling in space-based long-wave infrared detection, this study addresses the performance degradation of the cold finger in 60 K pulse tube cryocoolers (PTCs) under high-frequency operation for system mass reduction. Using a combined approach of numerical simulation and experimental validation, the geometry of the regenerator—a key component of the cold finger—and its graded stainless-steel wire-mesh packing strategy were systematically optimized, while the influence of operating parameters on cryocooler performance was analyzed. An integrated high-frequency prototype was subsequently developed.Experimental results demonstrate that with an input power of 250 W, a charging pressure of 6 MPa, and an operating frequency of 100 Hz, the 4.4 kg cryocooler achieves a no-load temperature of 29.75 K and delivers a cooling capacity of 9.76 W at 60 K, corresponding to a relative Carnot efficiency of 15.6%. When the input power is increased to 300 W, the system provides 3.8 W of cooling capacity at 40 K and 11.5 W at 60 K.The study further reveals the shift in the optimal operating frequency across different temperature zones and confirms the coupled governing mechanism of system efficiency, which is jointly determined by compressor efficiency and cold-finger efficiency.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"290 ","pages":"Article 129977"},"PeriodicalIF":6.9,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0