Thermal Science and Engineering Progress最新文献

{"title":"Solar-assisted mist cooling system for energy-efficient indoor climate control using hybrid machine learning optimisation","authors":"Osama Khan ,&nbsp;Rashid Khan ,&nbsp;Zeinebou Yahya ,&nbsp;Sabbah Ataya ,&nbsp;Aiyeshah Alhodaib ,&nbsp;Ashok Kumar Yadav ,&nbsp;Taufique Ahamad","doi":"10.1016/j.tsep.2025.104171","DOIUrl":"10.1016/j.tsep.2025.104171","url":null,"abstract":"<div><div>Amid escalating global temperatures and rising energy demands, this study investigates a solar-assisted mist-based renewable cooling system, optimized through advanced data-driven analysis for sustainable indoor climate control. The system utilizes a low-power RO pressure pump, mist nozzles, and a compact PVC duct integrated with a solar photovoltaic (PV) setup for energy autonomy. Ambient water is atomized and introduced into the airstream, enabling evaporative cooling with negligible carbon footprint. A hybrid priority-based machine learning clustering model (k-means) is applied to optimize key operating parameters such as flow rate, pump pressure, and pipe length. The analysis reveals strong correlations between cooling effect and mist rate (r = 0.981) and flow rate (r = 0.731), while power consumption moderately correlates with flow rate (r = 0.598) and pump pressure (r = 0.662). Cooling effect holds the highest priority (0.52), followed by room temperature and mist rate (0.20 each), with power consumption rated lowest (0.08). Cluster 1 stands out with 59.73 % cooling effect, 59.88 mist rate, and 25.2 °C room temperature, despite a 1.29 % power increase. Trial 24 is optimal with 5.05 °C cooling, 133.52  W power, 23.22 °C room temperature, and 58.4  ml/min mist. Validation analysis is supported by highly significant ANOVA F-values: cooling effect (24.04), mist rate (144.45), and power (31.75), all with Prob &gt; F &lt; 0.0001. The proposed device enables low-cost, sustainable passive cooling, supporting building decarbonisation.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104171"},"PeriodicalIF":5.4,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 24 kW metal halide Lamp-Based High-Flux solar simulator","authors":"Dilip Kumar ,&nbsp;Vaibhav Kumar Arghode","doi":"10.1016/j.tsep.2025.104169","DOIUrl":"10.1016/j.tsep.2025.104169","url":null,"abstract":"<div><div>A 24 kW high-flux solar simulator (HFSS) was designed, developed, and characterized to replicate concentrated solar radiation for high-temperature solar thermal applications. The HFSS consists of four 6 kW metal halide lamps, each coupled with ellipsoidal reflectors to achieve focused radiant heat flux at its secondary focal plane. To optimize the HFSS’s optical performance, a Monte Carlo ray tracing simulation was conducted to analyze light propagation within the lamp-reflector system and determine the plane of maximum heat flux. The accuracy of this simulation heavily depends on the arc source geometry, which plays a critical role in modeling the lamp-reflector configuration. The present work evaluates three different arc geometries viz. elliptical, cylindrical, and spherical. The elliptical arc source model, with a minor diameter of 10 mm and a major diameter of 23 mm, exhibited the closest agreement with experimental data. Notably, experimental results revealed that the plane of maximum heat flux did not coincide with the actual secondary focus of the reflector but rather occurred at a virtual secondary focus (VSF) located slightly above it. Experimental measurements recorded peak heat flux of 263 kW/m² for a single-lamp configuration and 647 kW/m² for the four-lamp module, while simulations based on the elliptical arc model predicted corresponding values of 275 kW/m² and 830 kW/m². A total radiant power output of 6.81  kW, corresponding to an energy transfer efficiency of 28.37 %, was recorded on a target area with a diameter of 170  mm at the virtual secondary focus (VSF) plane. These findings contribute to the advancement of HFSS technology, offering improved design methodologies for applications requiring intense and controlled solar irradiation.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104169"},"PeriodicalIF":5.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of thermal performance through improved heat transfer uniformity in a vertical latent heat thermal energy storage unit via the combination of annular and snowflake fins","authors":"Mengxi Luo ,&nbsp;Yongxue Zhang ,&nbsp;Yangbin Nie ,&nbsp;Bohui Lu ,&nbsp;Shuzhen Liu ,&nbsp;Jianxiong Luo","doi":"10.1016/j.tsep.2025.104170","DOIUrl":"10.1016/j.tsep.2025.104170","url":null,"abstract":"<div><div>In the vertical latent heat thermal energy storage (LHTES) units, natural convection can cause non-uniform temperature distribution and variability in liquid phase distribution of the phase change materials (PCMs), adversely affecting charging and discharging rates. To mitigate this impact, a novel annular-snowflake fin is proposed in this study. After validating the numerical model, this study compares the 3D transient heat transfer behavior of annular fins, snowflake fins, and four arrangements of combined annular–snowflake fins during charging and discharging processes. Key aspects analyzed include liquid fraction evolution, liquid phase and temperature distributions contours, uniformity indices, and other thermal performance metrics. The results indicate that integrating snowflake fins and annular fins significantly enhances the consistency of the thermal behavior of PCMs. Specifically, in Case E with the annular–snowflake structure, the complete melting and solidification times are reduced by 47.52% and 27.94%, respectively, compared to annular fins. Relative to snowflake fins, the reductions are 15.81% and 24.32%. Additionally, the average powers for heat storage and release increase by 71.56% and 30.84%, respectively, relative to annular fins, while the improvements over snowflake fins are 14.80% and 37.17%.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104170"},"PeriodicalIF":5.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation on the performance of solar air heater having staggered semi-frustum roughness on the absorber plate","authors":"Ramit Choudhury ,&nbsp;Apurba Layek ,&nbsp;Siddhita Yadav ,&nbsp;Abhimannyu Sharma","doi":"10.1016/j.tsep.2025.104167","DOIUrl":"10.1016/j.tsep.2025.104167","url":null,"abstract":"<div><div>Solar air heater is widely employed in applications such as space heating and agricultural drying, due to their simplicity and cost-effectiveness. In this study, a three-dimensional numerical investigation is conducted to evaluate the thermal and hydraulic performance of a solar air heater featuring an absorber plate modified with semi-frustum-shaped roughness elements. The simulations are performed using ANSYS FLUENT, incorporating the RNG k-ε turbulence model to capture the complex flow characteristics. The SIMPLE algorithm is applied for pressure–velocity coupling, and the finite volume method is used to discretize the governing equations. Two key geometric parameters, the relative exit radius and the relative roughness pitch<em>,</em> are varied within the ranges of 0.156–0.781 and 0.0078–0.0156, respectively. The analysis is conducted over a Reynolds number range of 4,000 to 24,000. Results indicate a considerable improvement in maximum heat transfer enhancement of 2.47 times compared to a smooth duct. The maximum value of the thermo-hydraulic performance parameter is found to be 1.70 at a relative exit radius of 0.0156 and a relative roughness pitch of 0.312.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104167"},"PeriodicalIF":5.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal behavior of Eyring-Powell liquids through porous compliant peristaltic walls under modified Darcy law and thermopherotic velocity","authors":"Shahid Farooq ,&nbsp;Husan Ara ,&nbsp;Maria Imtiaz ,&nbsp;Mohamed H. Helal","doi":"10.1016/j.tsep.2025.104168","DOIUrl":"10.1016/j.tsep.2025.104168","url":null,"abstract":"<div><div>Optimizing a variety of industrial and biological processes requires an understanding of peristalsis’s mass and heat transmission. The importance of Eyring-Powel liquid flow in a compliant curved channel with peristalsis is examined in this work, particularly in relation to mass and heat transfer, which is crucial for creating effective systems in chemical and biological engineering applications. The flow of a Powell-Eyring liquid across compliant curved channel walls is investigated using a modified Darcy resistance model that accounts for channel porosity, peristalsis, heat generation/absorption, chemical reaction, and mixed convection. The flow formulation is made simpler by assuming large wavelengths and low Reynolds numbers and the solution is found via a built-in numerical procedure. The findings indicate that while temperature rises as thermal slip values vary from 0 to 0.06, velocity decreases when the velocity slip parameter is increased from 0 to 0.03, and concentration reduces with an increasing solutal slip parameter from 0 to 0.09. Furthermore, the rate of mass and heat transmission decreases as the Darcy parameter increases. Understanding the peristaltic flow of fluids via porous and compliant channels can aid in the design of more effective medication delivery systems by optimizing the distribution of medicinal drugs.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104168"},"PeriodicalIF":5.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation on heat transfer characteristics of a two-phase closed thermosyphon with low filling ratios","authors":"Wandong Min ,&nbsp;Wei Zhong ,&nbsp;Yanping Yuan ,&nbsp;Dan Zhao ,&nbsp;Xiaoling Cao","doi":"10.1016/j.tsep.2025.104165","DOIUrl":"10.1016/j.tsep.2025.104165","url":null,"abstract":"<div><div>The two-phase closed thermosyphon (TPCT), an efficient heat transfer device, relies on the phase change of the working fluid. The distribution of the working fluid, which significantly affects the heat transfer mechanism, is influenced by the filling ratio (FR) along with other factors such as input power and geometry. Under certain conditions, the liquid pool height when the TPCT operates stably can typically be categorized into three scenarios: the liquid pool below the evaporator (often at low FRs), exceeding the evaporator (regular FRs), or reaching the condenser (high FRs). Previous research has shown that under low FRs, heat transfer deterioration occurs in the evaporator wall of TPCT. However, the existing literature has not fully elucidated the boiling mechanism underlying this phenomenon. In this paper, an improved CFD model of the TPCT was established to effectively simulate the flow and boiling process of liquid film in the evaporator section. The calculated data exhibited good consistency with experimental results, with a maximum relative error of 1.43 %. It was observed that the liquid film displays a wave-like pattern, which is attributed to the balance of gravity, surface tension, shear force, and buoyancy force when the TPCT is stable. As wall height decreases, there is an increase in amplitude for liquid film fluctuation above the evaporator wall height. Bubbles generated on the evaporator wall leads to an increase in the frequency of liquid film fluctuation and causes the liquid film to rupture. At low FRs, the distribution of liquid films in the evaporator generally can be distinguished into three scenarios: continuous liquid film, discontinuous liquid film, and dry-out areas. When the heating input is 232.89 W, the overall thermal resistance of methanol-TPCT with a 35 % FR decreased by 33.2 % compared to a 15 % FR, and only increased by 0.4 % compared to a 70 % FR. According to the findings in this paper, a proper FR of the TPCT can be employed for a given heating input, ensuring exceptional heat transfer performance and reducing the quantity of working fluid utilized.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104165"},"PeriodicalIF":5.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation on heat transfer characteristics of tungsten microwires","authors":"Zan Wang ,&nbsp;Haokang Liang ,&nbsp;Qixiang Zhang ,&nbsp;Mingyue Ruan ,&nbsp;Shuaikang Li","doi":"10.1016/j.tsep.2025.104163","DOIUrl":"10.1016/j.tsep.2025.104163","url":null,"abstract":"<div><div>The thermal conductivity(<span><math><mi>λ</mi></math></span>) and Lorenz number (<em>L</em>) of tungsten (W) microwires at varying temperatures were investigated using the 3<em>ω</em> method. The results show that the electrical conductivity of W microwires decreases significantly with rising temperature. However, an anomalous phenomenon was observed: <span><math><mi>λ</mi></math></span> exhibits a slight increase as temperature rises. X-ray Diffraction(XRD) analysis reveals that reduced lattice constants diminish phonon scattering mechanisms while enhancing phonon group velocity, leading to higher thermal conductivity. Grain refinement increases grain boundary scattering, which suppresses phonon thermal transport, thereby weakening the contribution of phonon thermal conductivity(<span><math><msub><mi>λ</mi><mrow><mi>ph</mi></mrow></msub></math></span>). Calculated phonon spectra demonstrate that smaller lattice constants result in higher phonon group velocities, positively contributing to phonon heat conduction. In microwires dominated by electronic heat capacity, electronic thermal conductivity(<span><math><msub><mi>λ</mi><mi>e</mi></msub></math></span>) displays a weak upward trend with temperature. Consequently, under the combined effects of these factors, the <span><math><mi>λ</mi></math></span> of the microwires slightly increases with temperature. Additionally, the <em>L</em> of metallic W is approximately 30 % higher than the Sommerfeld value, exhibiting unique thermal properties, and it shows a minor increase with temperature, gradually converging to 3.29 V²/K².</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104163"},"PeriodicalIF":5.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-objective constructal designs for fork-shaped cavities with minimizing maximum-temperature-difference and entropy-generation-rate","authors":"Hongwei Zhu ,&nbsp;Lingen Chen ,&nbsp;Huijun Feng ,&nbsp;Yanlin Ge","doi":"10.1016/j.tsep.2025.104161","DOIUrl":"10.1016/j.tsep.2025.104161","url":null,"abstract":"<div><div>Constructal design for a fork-shaped cavity model with maximum-temperature-difference (MTD) minimization was performed previously. Herein, it is studied furtherly. Firstly, constructal designs considering entropy-generation-rate (EGR) minimization are performed under cases of rectangular solid wall with heat-generation and heated externally, and are compared with results considering MTD minimization. Aspect ratio (<span><math><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>/</mo><msub><mi>L</mi><mn>0</mn></msub></mrow></math></span>) of fork-shaped cavity is taken as design variable, and influences of aspect ratio (<span><math><mrow><mi>H</mi><mo>/</mo><mi>L</mi></mrow></math></span>) of rectangular solid wall, porosity (<span><math><mrow><mi>Φ</mi></mrow></math></span>) of fork-shaped cavity and number (<span><math><mrow><mi>N</mi></mrow></math></span>) of branches of fork-shaped cavity on constructal designs are studied. Secondly, constructal designs are performed by minimizing a composite-function of linear weighting-sum of EGR and MTD. Thirdly, multi-objective constructal designs are performed based on NSGA-II, and deviation indexes with three decision-making methods are compared to determine design schemes. When <span><math><mrow><mi>Φ</mi><mo>=</mo><mn>0.6</mn></mrow></math></span>, <span><math><mrow><mi>H</mi><mo>/</mo><mi>L</mi><mo>=</mo><mn>1</mn></mrow></math></span> and <span><math><mrow><mi>N</mi><mo>=</mo><mn>1</mn></mrow></math></span>, under two cases, optimal <span><math><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>/</mo><msub><mi>L</mi><mn>0</mn></msub></mrow></math></span> considering EGR minimization are 0.79 and 0.61 respectively, while optimal <span><math><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>/</mo><msub><mi>L</mi><mn>0</mn></msub></mrow></math></span> considering MTD minimization are 0.7 and 0.664 respectively; composite functions are decreased by 21.06% and 1.29% compared to their initial designs respectively; optimal <span><math><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>/</mo><msub><mi>L</mi><mn>0</mn></msub></mrow></math></span> gained in Pareto frontiers are located between 0.7–0.79 and 0.61–0.664 respectively, and results of TOPSIS decision-making method have the smallest deviation indexes, and are selected as the best compromise design schemes. The major contribution herein are introducing EGR minimization objective into constructal-design for fork-shaped cavities with different conditions, and realizing MOOs for cavities with weighting-sum function, NSGA-II and three decision-making methods.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104161"},"PeriodicalIF":5.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal carbonization of waste Rosa roxburghii Tratt pomace into solid fuel: mechanisms, combustion characteristics and thermodynamic studies","authors":"Pengpeng Chen ,&nbsp;Peng Xia ,&nbsp;Lingyun Zhao ,&nbsp;Ke Wang ,&nbsp;Yuanzhu Yao ,&nbsp;Cong Yang ,&nbsp;Yun Ling","doi":"10.1016/j.tsep.2025.104157","DOIUrl":"10.1016/j.tsep.2025.104157","url":null,"abstract":"<div><div><em>Rosa roxburghii Tratt</em> (RRT) pomace, a major byproduct of juice processing, exhibits a high specific surface area and roughness, demonstrating significant potential for biomass energy production. Improper disposal may lead to environmental pollution and resource waste; thus, high-value utilization offers both economic and environmental benefits. This study employed hydrothermal carbonization (HTC) to convert RRT pomace into highly stable biomass fuel, aiming to elucidate the reaction mechanism and identify the optimal process conditions. Proximate and ultimate analyses revealed that, with increasing temperature and duration, the hydrochar yield and volatile matter content decreased, while the fixed carbon content and calorific value significantly increased, exhibiting coal-like characteristics. Structural evolution analysis revealed that deoxygenation and aromatization played dominant roles, with an increase in tetra-substituted aromatic rings and a decrease in oxygen-containing functional groups, confirming the transformation of the carbon skeleton into a highly stable bituminous coal-like structure. Under the optimal condition of 225 ℃ for 6 h, the resulting hydrochar exhibited an elevated ignition temperature of 323.14 ℃, significantly improved storage safety, a 25.24 % reduction in average activation energy, and a negative entropy change, indicating enhanced system ordering and reduced reaction energy barriers. Mechanistic studies indicated that the HTC process involved three stages: hydrolysis-dehydration, condensation-aromatization, and carbonization, with 225 ℃ identified as the threshold temperature that balances carbon enrichment and ash suppression. This study offers a theoretical foundation for high-value utilization of RRT pomace, thereby contributing to the resource recovery of agricultural waste and the development of clean energy.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104157"},"PeriodicalIF":5.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on longitudinal ventilation smoke control in tunnel emergency lay-by fires under different ambient pressures","authors":"Chenhao Ran ,&nbsp;Le Wu ,&nbsp;Feng Li ,&nbsp;Dong Yuan ,&nbsp;Guoqing Li ,&nbsp;Maohua Zhong","doi":"10.1016/j.tsep.2025.104158","DOIUrl":"10.1016/j.tsep.2025.104158","url":null,"abstract":"<div><div>This study investigates the effectiveness of longitudinal ventilation in controlling fire-induced smoke within tunnel emergency lay-bys under varying ambient pressures through full-scale experiments and numerical simulations. The results indicate that the cross-sectional variation in emergency lay-by areas leads to energy losses in the flow field and uneven velocity distribution, which hinder smoke control. When the upper-layer smoke spreads to the edge of the lay-by and impacts the side wall, energy is dissipated. However, the resulting backflow isolates the upper-layer smoke from the surrounding air, reducing heat loss. The side wall at the edge of the emergency lay-by can block only a limited thickness of smoke. Since lower ambient pressure results in a thicker smoke layer, altitude significantly affects smoke control performance in emergency lay-by areas. Although the emergency lay-by structure is generally disadvantageous for smoke control, it is easier to contain smoke within the lay-by than to control it downstream of the fire source. A dimensionless confinement velocity model is proposed, providing a reference for smoke control system design and emergency response in highway tunnel emergency lay-bys at various altitudes.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104158"},"PeriodicalIF":5.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}