Fire Safety Journal最新文献_第5页

A novel fire hazard evaluation method for cable sheaths under various ageing conditions 不同老化条件下电缆护套火灾危险性评估新方法

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-05 DOI: 10.1016/j.firesaf.2025.104572

Hui Liu, Wenqiang Wang, Long Yan, Zhisheng Xu

Fire hazard is one of the most serious security threats to the service cable under different environmental conditions, and comprehensive evaluation is critical for fire safety. A novel evaluation method of fire hazard for cable sheaths after various ageing treatment was established based on entropy weight method (EWM), analytic hierarchy process (AHP), grey relational analysis (GRA), and technique for order preference by similarity to an ideal solution (TOPSIS) method. By analyzing factors that leaded to fire accidents, 15 evaluation indicators were determined from three aspects, including ignition, heat and smoke hazards. Combined with the characteristics of each evaluation method, the AHP-EWM method was used to obtain combination weight values, and the comprehensive evaluations for the fire hazards of the sheaths under different ageing conditions were realized by the TOPSIS-GRA method. The results show that the heat hazard of low-smoke halogen-free sheath is higher, while the smoke hazard of PVC sheath is larger. Simultaneously, the negative impact of hygrothermal condition is the most significant, succeeded by the salt spray condition, while the weaken effect of thermal condition is the smallest. In contrast to the traditional evaluation method of fire hazards, the evaluation results from the TOPSIS-GRA method are more accurate and reliable.

火灾是不同环境条件下服务电缆最严重的安全威胁之一，综合评价是保障服务电缆防火安全的关键。基于熵权法（EWM）、层次分析法（AHP）、灰色关联分析法（GRA）和理想解相似性排序偏好法（TOPSIS），建立了不同老化处理后电缆护套火灾危险性评价方法。通过分析导致火灾事故的因素，从着火、热和烟雾危害三个方面确定了15个评价指标。结合各评价方法的特点，采用AHP-EWM法获得组合权重值，采用TOPSIS-GRA法实现对不同老化条件下护套火灾危险性的综合评价。结果表明，低烟无卤护套的热危险性较高，而PVC护套的烟危险性较大。同时，湿热条件的负面影响最为显著，其次是盐雾条件，而热条件的弱化作用最小。与传统的火灾危险性评价方法相比，TOPSIS-GRA方法的评价结果更加准确可靠。

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引用次数: 0

Reappraisal of Jin's visibility through fire smoke experiment: Insights into signage visibility and the impact of ambient light 通过火烟实验重新评价Jin的可见度：对标识可见度和环境光影响的洞察

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-05 DOI: 10.1016/j.firesaf.2025.104573

Wai Kit Cheung , Jakub Bielawski , Lukas Arnold , Xinyan Huang , Wojciech Węgrzyński

Jin's experiments in the 1970s contributed to fire evacuation research, but only examined relatively high ambient light levels. By replicating the Jin's experimental setup and varying ambient light level, we explore the relationship between smoke extinction coefficient, background illumination and signage emitting light intensity under low-light real-world emergency scenarios. Firstly, we confirm Jin's observation of a linear relationship between smoke extinction coefficient (

σ

) and visibility distance (

V

), although our measurements of

σ

are 7–11 % higher under equivalent signage luminance. Our findings on the

σ

versus normalized brightness

π L_{t} / E

at a 15.5 m distance align with Jin's results, while a 20 % discrepancy is observed at 10.5 m and 5.5 m distances. At high ambient light (180 lx), the

K = σ V

is comparable in Jin's experiment (from 5 to 8) and this work (from 4.7 to 9.5). However, at low ambient light (less than 22 lx), the signage remains visible in higher smoke extinction coefficients (with K from 6 to 11). The critical extinction coefficient decreases by nearly 40 % for every 5 m increase in visibility distance. This work deepens the understanding of smoke visibility under a dark fire environment, which may help guide fire signage design and inspire new fire evacuation research.

金在20世纪70年代的实验为火灾疏散研究做出了贡献，但只检查了相对较高的环境光水平。通过复制Jin的实验装置和不同的环境光水平，我们探索了在低光的现实世界紧急情况下，烟雾消光系数、背景照度和标牌发光强度之间的关系。首先，我们证实了Jin对烟雾消光系数（σ）和可见距离(V)之间的线性关系的观察，尽管在等效标识亮度下我们的σ测量值高出7 - 11%。我们在15.5 m距离处的σ与归一化亮度πLt/E的结果与Jin的结果一致，而在10.5 m和5.5 m距离处观察到20%的差异。在高环境光（180 lx）下，K=σV在Jin的实验（从5到8）和本工作（从4.7到9.5）中是相当的。然而，在低环境光（小于22 lx）下，标识在较高的烟雾消光系数（K从6到11）下仍然可见。能见度每增加5 m，临界消光系数降低近40%。本研究加深了对暗火环境下烟雾可见度的认识，有助于指导防火标识设计，启发新的火灾疏散研究。

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引用次数: 0

Impact of high-concentration smoke aerosols on radar electromagnetic wave propagation in building fire 高浓度烟雾气溶胶对建筑火灾中雷达电磁波传播的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-03 DOI: 10.1016/j.firesaf.2025.104568

Song Wang , Jing Geng , Wenguo Weng

This study investigates the impact of high-concentration smoke aerosols on radar electromagnetic wave propagation in building fire scenarios. A computational model based on Mie scattering theory and existing databases was developed to evaluate the influence of smoke aerosols on radar signals. Additionally, a voxel-based Finite-Difference Time-Domain (FDTD) simulation method was designed to model complex random media, and simulations were conducted to validate the computational model. An experimental platform was also constructed to assess the impact of high-concentration smoke on radar electromagnetic waves, utilizing three types of radars: NVA-R641, X4M03, and IWR6843. Data collected under typical smoke conditions revealed attenuation coefficients of approximately 0.03 dB/m at 2.95 GHz, 0.37 dB/m at 8.75 GHz, and 0.76 dB/m at 60 GHz. These results support the theoretical model and demonstrate the feasibility of the simulation approach. This research provides a comprehensive framework for understanding and predicting the effects of high-concentration smoke aerosols on radar systems in building fire scenarios, offering valuable tools for optimizing radar performance and enhancing the reliability of life-saving operations in smoke-filled environments.

研究了建筑火灾场景下高浓度烟雾气溶胶对雷达电磁波传播的影响。基于Mie散射理论和现有数据库，建立了烟雾气溶胶对雷达信号影响的计算模型。此外，设计了一种基于体素的时域有限差分（FDTD）模拟方法来模拟复杂随机介质，并进行了仿真验证。利用NVA-R641、X4M03和IWR6843三种型号的雷达，搭建了一个实验平台来评估高浓度烟雾对雷达电磁波的影响。在典型烟雾条件下收集的数据显示，衰减系数在2.95 GHz时约为0.03 dB/m，在8.75 GHz时约为0.37 dB/m，在60 GHz时约为0.76 dB/m。这些结果支持了理论模型，并证明了仿真方法的可行性。本研究为理解和预测建筑火灾场景中高浓度烟雾气溶胶对雷达系统的影响提供了一个全面的框架，为优化雷达性能和提高烟雾弥漫环境中救生操作的可靠性提供了有价值的工具。

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引用次数: 0

Experimental investigation of cellular steel beams at ambient and elevated temperatures 室温和高温条件下蜂窝钢梁的试验研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-03 DOI: 10.1016/j.firesaf.2025.104574

Luana V. da Silva , Nickolas Giacomitti , Débora Ferreira , Nuno Lopes , Luís M.R. Mesquita

Cellular steel beams, commonly used in modern construction, exhibit complex failure mechanisms that have not been thoroughly explored, especially under fire conditions. This research investigates the structural behaviour of cellular beams under both ambient and elevated temperatures, with a focus on load-bearing capacity and failure modes. Experimental tests were conducted on a solid beam and six cellular beams with varying hole spacings and diameters at different temperatures. All beams were tested under three-point bending, subjecting the openings and the web posts to different combinations of bending moments and shear forces. Experimental maximum loads and failure modes are compared with the design method of EN1993-1-13 and EN1993-1-2. At ambient temperature, failure modes varied with beam design: specimens with smaller opening spacings failed by web-post buckling, while larger openings resulted in a Vierendeel mechanism. While the Eurocode predictions for load capacity were conservative under ambient conditions, the design model did not accurately predict the correct failure mode. Elevated temperatures significantly reduced the load capacity and, in some cases, changed the collapse mechanism. These results highlight that current design rules are unreliable in predicting the failure mode and may not ensure safety at higher temperatures, stressing the need for specific design rules for cellular beams in fire conditions.

在现代建筑中广泛使用的蜂窝钢梁，其复杂的破坏机制尚未得到充分的研究，特别是在火灾条件下。本研究调查了蜂窝梁在环境和高温下的结构行为，重点关注承重能力和破坏模式。在不同温度下，对一根实心梁和6根孔间距和直径不同的蜂窝梁进行了实验测试。所有梁都在三点弯曲下进行了测试，使开口和腹板柱受到不同的弯矩和剪力组合。将试验最大载荷和破坏模式与EN1993-1-13和EN1993-1-2的设计方法进行了比较。在环境温度下，梁的破坏模式因梁的设计而异：开口较小的试件因网柱屈曲而破坏，而开口较大的试件则因Vierendeel机制而破坏。虽然欧洲规范对环境条件下负荷能力的预测是保守的，但设计模型不能准确预测正确的失效模式。高温显著降低了承载能力，在某些情况下，还改变了坍塌机制。这些结果强调，目前的设计规则在预测失效模式方面是不可靠的，并且可能无法确保高温下的安全，强调需要针对火灾条件下的蜂窝梁制定特定的设计规则。

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引用次数: 0

Experimental investigation on mechanical properties of cast steel at elevated temperatures 铸钢高温力学性能的试验研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-01 DOI: 10.1016/j.firesaf.2025.104571

Hongbo Liu , Bingxu Han , Liulu Guo , Zhihua Chen

Cast steel is extensively used in diverse building structures, especially for complex joints and members. To guarantee the safety of cast steel components during fire events, precise characterization of mechanical properties and constitutive behavior of cast steel at elevated temperatures is imperative. This study presents a comprehensive experimental investigation of G20Mn5N and G20Mn5QT cast steels. Key mechanical property indexes of cast steel at elevated temperatures were determined and compared to code-specified values and high-temperature data for conventional structural steels. Results indicate that the cast steels exhibited a blue brittleness phenomenon at 300 °C, characterized by increased ultimate strength and reduced toughness and ductility, ultimately predisposing them to brittle failure. Cast steel exhibited pronounced thermochromic behavior and ductile damage characteristics at elevated temperatures. With increasing temperature, the modulus of elasticity, yield strength, and ultimate strength of cast steel decreased, while elongation initially diminished before increasing. G20Mn5QT demonstrated superior fire resistance compared to G20Mn5N. Highly accurate empirical prediction equations for critical mechanical properties and theoretical stress-strain formulas at elevated temperatures were developed.

铸钢广泛应用于各种建筑结构，特别是复杂的接缝和构件。为了保证铸钢构件在火灾中的安全，精确表征铸钢在高温下的力学性能和本构行为是必不可少的。本文对G20Mn5N和G20Mn5QT铸钢进行了综合试验研究。测定了铸钢在高温下的关键力学性能指标，并与规范规定的数值和常规结构钢的高温数据进行了比较。结果表明，铸钢在300℃时表现出蓝色脆性现象，其特征是极限强度增加，韧性和延展性降低，最终导致脆性破坏。铸钢在高温下表现出明显的热致变色行为和延展性损伤特征。随着温度的升高，铸钢的弹性模量、屈服强度和极限强度下降，伸长率先降低后升高。与G20Mn5N相比，G20Mn5QT表现出更好的耐火性。建立了高精度的临界力学性能经验预测方程和高温下的应力-应变理论公式。

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引用次数: 0

Cooling methods impact on post-fire residual bond properties of bimetallic steel bars in seawater concrete 冷却方式对海水混凝土中双金属钢筋火灾后残余粘结性能的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-30 DOI: 10.1016/j.firesaf.2025.104569

Xuanyi Xue , Fei Wang , Jianmin Hua , Neng Wang , Shuang Yan

The bimetallic steel bar (BSB) is a new type of corrosion-resistant steel bar composed of stainless steel cladding and carbon steel substrate. In ocean engineering, the combination of BSB and seawater concrete can better utilize in-situ resources, and reduce the cost of seawater desalination and material transportation. To evaluate the residual bearing performance of the bimetallic steel bar-seawater concrete (BSBSC) structure post-fire, it is essential to elucidate the bond behavior of BSBSC exposed to elevated temperatures. In this study, the effects of high temperatures and cooling methods on the bond performance of BSBSC were investigated. The results indicated that the elevated temperature significantly weakened the bonding strength of BSBSC. The bonding strength of BSBSC exposed to 400 °C had decreased by a maximum of 63.54 %. As the temperature increased, the difference in bonding strength between air cooling and water cooling decreased from 27.61 % to 3.60 %. The peak-load slip initially declined and subsequently rose as the temperature increased with the transition temperature between 200 °C and 400 °C. A predictive bond stress-slip constitutive model for BSBSC was formulated. The design method for steel bar anchorage length in current design standards has been revised to take into account the fire risk.

双金属棒材（BSB）是一种由不锈钢包层和碳钢基体组成的新型耐腐蚀棒材。在海洋工程中，BSB与海水混凝土的结合可以更好地利用就地资源，降低海水淡化和材料运输的成本。为了评价双金属钢筋-海水混凝土（BSBSC）结构火灾后的残余承载性能，有必要研究高温下BSBSC的粘结行为。在本研究中，研究了高温和冷却方式对BSBSC粘结性能的影响。结果表明，温度升高显著降低了BSBSC的结合强度。BSBSC在400℃下的结合强度最大下降了63.54%。随着温度的升高，风冷与水冷的结合强度差由27.61%减小到3.60%。在200℃~ 400℃之间，随着温度的升高，峰载滑移量呈先下降后上升的趋势。建立了BSBSC的预测粘结应力-滑移本构模型。对现行设计标准中钢筋锚固长度的设计方法进行了修订，以考虑火灾风险。

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引用次数: 0

Surrogate based uncertainty quantification in pyrolysis modeling: A comparative analysis 热解建模中基于代理的不确定性量化：比较分析

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-28 DOI: 10.1016/j.firesaf.2025.104570

Hamza Jamil, Fabian Brännström

In this work we analyze and compare the uncertainty propagation in a comprehensive pyrolysis model that captures an experimental setup using different approaches: namely polynomial chaos expansion (PCE), proper orthogonal decomposition with interpolation (PODI), Gaussian process regression (GPR) and quasi-Monte Carlo simulations. We start with inverse modeling to obtain the nominal parameter values for a set of kinetic and thermal parameters that devise the essential equations of the model. This is followed by a global sensitivity analysis to choose the most critical parameters for which the stochastic uncertainty is studied in the output over time. For the uncertainty, we observe the convergence behavior for mean, standard deviation, skewness and kurtosis. The statistical moments convergence analysis shows PCE to exhibit comparatively poor convergence behavior for standard deviation, and divergence for skewness and kurtosis. On the other hand, the computational effort required for GPR does not scale well in terms of accuracy with increased number of samples. Whereas, PODI is observed to converge faster while being comparatively less computationally intensive than other surrogate approaches. In conclusion, PODI poses as the most prominent approach among the aforementioned for uncertainty quantification in highly resolved pyrolysis and flame spread models.

在这项工作中，我们分析和比较了一个综合热解模型中的不确定性传播，该模型采用了不同的方法，即多项式混沌展开（PCE）、适当的正交插值分解（PODI）、高斯过程回归（GPR）和准蒙特卡罗模拟。我们从逆建模开始，获得一组动力学和热参数的标称参数值，从而设计出模型的基本方程。其次是全局敏感性分析，以选择最关键的参数，研究随时间输出的随机不确定性。对于不确定性，我们观察到均值、标准差、偏度和峰度的收敛性。统计矩收敛分析表明，PCE对标准差表现出较差的收敛性，对偏度和峰度表现出发散性。另一方面，GPR所需的计算工作量随着样本数量的增加而不能很好地扩展精度。然而，与其他代理方法相比，PODI的收敛速度更快，而计算强度相对较低。综上所述，PODI是上述方法中对高分辨热解和火焰蔓延模型的不确定性量化最突出的方法。

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引用次数: 0

Various methods of flame extinguishing by CO2 hydrate 用二氧化碳水合物灭火的各种方法

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-27 DOI: 10.1016/j.firesaf.2025.104567

S.Y. Misyura , V.S. Morozov , P.A. Strizhak

Extinguishing the flame of wooden samples by various means: CO₂ hydrate tablet, CO₂ hydrate powder, sand, NH₄H₂PO₄, water spray, foam spray (water and SDS) was studied experimentally and theoretically. The experiments were performed both outdoors and in a closed chamber. The tablet and the CO₂ hydrate powder have shown the minimum sample weight for complete quenching. The novelty of the research lies in the use of shells with tablets to extinguish a fire in a closed room (chamber). Previous studies were carried out with the CO₂ hydrate powder. The presented work shows the advantages of using CO₂ hydrate tablets. Experiments were performed for different sample masses and in a wide range of closed chamber volumes. After the projectile throw into the chamber, three characteristic modes are realized: heating and dissociation of tablets, rupture of the shell and instantaneous release of CO₂, and longer dissociation of CO₂ hydrate tablet. It is shown that extinguishing in the open air is realized mainly due to the heat of phase transitions. In a closed room, the predominant extinguishing effect is associated with very rapid release of CO₂ gas and rapid suppression of oxygen and oxidation reactions. The dissociation of a gas hydrate tablet, the tablet heating time until the shell break, and the maximum dissociation time of the tablet are simulated. A technique of multi-cycle quenching with a delay in the time of rupture of several shells is proposed.

实验和理论研究了不同灭火方法：CO2水合片、CO2水合粉、沙子、NH4H2PO4、水喷雾、泡沫喷雾（水和SDS）。实验在室外和封闭的室内进行。片剂和CO2水合物粉末显示了完全淬火所需的最小样品重量。这项研究的新颖之处在于使用带有药片的贝壳来扑灭封闭房间（密室）中的火。以前的研究都是用二氧化碳水合物粉末进行的。本文的工作显示了使用二氧化碳水合物片的优点。实验进行了不同的样品质量和广泛的封闭腔体积范围。抛丸入腔后，实现三种特征模式：片剂加热解离、壳体破裂瞬间释放CO2、CO2水合物片剂长时间解离。结果表明，在露天环境中灭火主要是通过相变热来实现的。在一个封闭的房间里，主要的灭火效果与CO2气体的快速释放和氧气和氧化反应的快速抑制有关。模拟了一种气体水合物片剂的解离过程、片剂加热至破壳时间以及片剂的最大解离时间。提出了一种延迟多壳断裂时间的多循环淬火技术。

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引用次数: 0

Critical ignition limits and thermal behaviors of asphalt combustion under varied radiation conditions: Experimental exploration and 2-D Smouldering Kinetics Interpretation 不同辐射条件下沥青燃烧的临界点火极限和热行为：实验探索和二维阴燃动力学解释

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-23 DOI: 10.1016/j.firesaf.2025.104564

Kai Zhu , Dan Zhao , Han Yuan , Qiang Wang , Linghan Zhou , Ke Wu , Zhirong Liang

Asphalt, a carbon-rich and chemically complex material, exhibits intricate combustion behavior under fire conditions. Despite its widespread use in over 90 % of pavements in the United States and China, its ignition dynamics under varying radiative conditions remain poorly understood. This research explored the thermal behaviors of combustible asphalt under various radiation intensities (0–50 kW/m²) and durations (0–60 min) experimentally, with smouldering reaction kinetics interpreted numerically. It is observed that under sufficient radiation duration (60 min), 5 kW/m² is the critical limit of radiation intensity; while under high radiation intensity (50 kW/m²), nearly 1 min is the critical limit of radiation duration. 2-D Smouldering Kinetics Interpretation revealed that critical radiation intensity determines the overcoming of activation energy, and critical radiation duration determines the potential of thermal-storage capacity for ignition to trigger smouldering combustion. Moreover, the reaction kinetics reflected the transition from pyrolysis-dominated to pyrolysis/oxidation-coupled reactions, significantly varying the asphalt/char/ash proportions. The findings establish critical thresholds for asphalt smoldering ignition, which are characterized by dual logarithm correlation between the radiation intensity and ignition time. This is complemented by fundamental analysis of species evolution dynamics and chemical energy distribution, providing insights valuable to fire safety science.

沥青是一种富含碳且化学性质复杂的材料，在火灾条件下表现出复杂的燃烧行为。尽管它在美国和中国90%以上的路面上广泛使用，但其在不同辐射条件下的点火动力学仍然知之甚少。本研究通过实验研究了不同辐射强度（0-50 kW/m2）和持续时间（0-60 min）下可燃沥青的热行为，并对阴燃反应动力学进行了数值解释。在足够的辐射持续时间（60min）下，5kw /m2是辐射强度的临界极限；而在高辐射强度（50 kW/m2）下，近1 min是辐射持续时间的临界极限。二维阴燃动力学解释表明，临界辐射强度决定了活化能的克服，临界辐射持续时间决定了点火蓄热能力触发阴燃的潜力。反应动力学反映了从热解为主反应到热解/氧化耦合反应的转变，沥青/炭/灰分比例发生了显著变化。研究结果建立了沥青阴燃的临界阈值，该阈值与辐射强度和着火时间呈双对数相关关系。这是对物种进化动力学和化学能分布的基本分析的补充，为消防安全科学提供了有价值的见解。

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引用次数: 0

Radiation effects on horizontal flame spread under non-steady airflows 非定常气流下辐射对火焰水平传播的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-23 DOI: 10.1016/j.firesaf.2025.104565

Pablo E. Pinto , Xiuqi Xi , Maria Thomsen , James L. Urban

Thermal radiation from the flame to the unburned fuel plays a key role in horizontal concurrent flame spread by heating the fuel surface and influencing the spread of the flame. This work investigates thermal radiation in horizontal concurrent flame spread under non-steady forced airflow conditions. Experiments are conducted using black cast polymethyl methacrylate (PMMA) sheets with a thickness of 1 mm as fuel. A non-steady airflow with a sinusoidal profile is applied in each experiment, with a baseline of 300 mm/s, amplitudes of 100 and 200 mm/s, and frequencies of 1/32, 1/16, and 1/8 Hz. Radiation emitted by the flame is partially captured through heat flux gauge measurements and interpreted using geometrical data extracted from video footage. View factors between the flame and target surfaces (heat flux gauge and unburned sample) are calculated using a contour integral technique, with contours derived from parametric representations of the flame geometry based on flame height, burnout front, pyrolysis front, and flame tip position. This allows estimation of radiative heat transfer to the heated zone. Results show that the magnitude of flame radiation to the sample does not change significantly under non-steady airflow; however, the size of the heated zone exhibits a strong transient response. This response is attributed to the transient variation in flame extension length over the unburned surface. Additionally, two-dimensional spatial distributions of incident radiative heat flux to the heated zone are calculated and analyzed. The average flame spread rate is estimated by integrating the incident radiative heat flux, neglecting the convective contribution, which resulted in an underestimation of 18%–36% compared with the experimental flame spread rate.

火焰对未燃烧燃料的热辐射通过加热燃料表面，影响火焰的传播，在火焰水平同步传播中起着关键作用。本文研究了非定常强迫气流条件下火焰水平同步传播过程中的热辐射。实验采用厚度为1mm的黑色铸造聚甲基丙烯酸甲酯（PMMA）片材作为燃料。每次实验均采用非稳态正弦气流，基线为300 mm/s，振幅为100和200 mm/s，频率为1/32、1/16和1/8 Hz。火焰发出的辐射通过热通量计测量部分捕获，并使用从视频片段中提取的几何数据进行解释。火焰和目标表面（热通量计和未燃烧样品）之间的视图因子使用轮廓积分技术计算，轮廓源自基于火焰高度、燃尽前沿、热解前沿和火焰尖端位置的火焰几何参数表示。这样就可以估计向受热区传递的辐射热量。结果表明：在非稳态气流下，火焰对试样的辐射强度变化不大；然而，加热区的大小表现出强烈的瞬态响应。这种响应归因于火焰在未燃烧表面上延伸长度的瞬态变化。此外，还计算和分析了加热区的入射辐射热流密度的二维空间分布。平均火焰蔓延率是通过对入射辐射热流的积分来估算的，忽略了对流的贡献，与实验火焰蔓延率相比，低估了18%-36%。

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引用次数: 0