共查询到19条相似文献,搜索用时 164 毫秒
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《消防技术与产品信息》2016,(2)
火灾场景重构对于消防人员调查火灾事故发生发展过程具有重要的参考价值,而基于FDS的数值模拟方法是重构火灾场景的主要手段。本文通过数值模拟过程,对一起酒店纵火案进行调查分析,用计算结果在关键点上与实际火灾情况进行对比分析,从而验证计算结果的合理性,然后通过模拟结果确定整个火灾发生发展的细节。 相似文献
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古建筑大悲阁火灾蔓延数值模拟 总被引:3,自引:4,他引:3
以大悲阁作为研究对象,利用FDS软件对大悲阁木结构阁楼式古建筑进行数学建模,计算不同火灾场景下火灾蔓延过程,得到初期火灾烟气蔓延及温度场分布。通过对火灾数值模拟的分析研究,提出了合理的火灾防治对策,以最大限度地减小火灾损失。 相似文献
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摘 要:网格划分是火灾数值模拟的重要环节,对模拟结果的精度以及模拟时间有很大影响。针对火灾数值模拟中的网格划分问题,提出了一种基于大涡模拟的网格划分优化方法。根据大涡模拟的原理,给出了滤波尺度的计算方法,并根据滤波尺度和网格比系数对火场中不同区域的网格尺寸进行优化处理。将优化方法应用于高层建筑火灾的数值模拟,运用FDS软件分别针对优化前网格、优化后网格以及精细网格进行数值模拟,对不同网格划分下的温度、氧气和二氧化碳体积分数进行比对。结果表明:网格优化后,模拟结果与精细网格之间相关系数的均值为0.987,保证了模拟精度;同时,模拟运行时间降低为精细网格的16%,有效提升了火灾模拟的计算效率。 相似文献
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介绍地质统计学基本原理,利用火灾动力学模拟软件FDS对某一火灾场景进行模拟计算,以火场烟气中一氧化碳的体积分数为例,在FDS计算结果基础上进行克立格估值计算,并以三维立体图直观显示其空间分布特征。将克立格估值结果与FDS计算结果进行对比,验证该估值方法的可靠性,并展望地质统计学在消防领域内的应用前景。 相似文献
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《消防技术与产品信息》2016,(7)
分析了地下机械车库的火灾特点,参考汽车火灾试验,确定了火灾分析的基础数据,从火灾增长速率、火灾蔓延、被引燃临界热释放速率、自动喷水灭火系统的动作时间及不同的火灾场景FDS数值模拟等几方面,对地下机械车库火灾危险性进行了探讨。 相似文献
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FDS场模拟计算中的网格分析 总被引:8,自引:0,他引:8
基于场模拟的火灾动力学模型(FDS)中网格的划分直接影响到计算结果的误差,甚至关系到计算结果的正确性。运用FDS对相同计算区域内的4种不同网格划分情况分别进行数值模拟,比较不同网格尺寸对计算结果的影响,从而对FDS的网格划分问题得到进一步的认识。 相似文献
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将数值模拟中的大涡模拟方法应用于某汽车配件城仓库火灾场景重构,对火灾原因和过程进行分析。根据现场人员证词和燃烧现场取证,对火灾的发生进行场景重构模拟,确定火灾是由电气短路造成。将模拟结果中关键部位的温度、有毒气体和烟气浓度等数据与火灾现场专家勘察结果对比,排除了人为纵火的可能性。采用并行运算方法,较好的预测了火灾发展和有毒烟气的运动。为实际火灾场景的调查提供了数值模拟的科学方法。 相似文献
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The carbon black trace is an important characteristic in a building fire accident and becomes crucial evidence in fire investigation. Based on the particle deposition theory, the mathematical model is established for the carbon black trace in a building fire. The numerical model of the carbon black trace is implemented into the Fire Dynamics Simulator (FDS) software. The total mass of the carbon black particle deposited on the wall surface can be calculated quantitatively and be simulated visually. The proposed model is applied into a fire accident as a validation. A numerical model is used to simulate the fire accident. In numerical simulations, the grid size resolution is analyzed. The accident reconnaissance data, accident interview record and accident scene photo/video are compared with the results of numerical simulations. It shows that the simulation results have a good agreement with those in the fire accident, which validates the mathematical model in this study. The proposed method can provide useful data for fire reconstruction and fire investigation. 相似文献
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对贵州一起"三合一"场所火灾进行建模重构,依据真实火灾数据,利用FDS软件设置相关参数重现火灾的发展过程,得到温度、烟气蔓延数据,并与实际火灾现场相应部位的痕迹特征进行对照,验证了起火部位和火灾蔓延发展过程.通过温度、CO体积分数切片以及相对有效暴露剂量(FED)的综合分析,对最终人员在高温与烟气的共同作用下死亡做出了... 相似文献
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采用FDS建立弧形隧道火灾模型,对模型进行模拟计算,结合Wu&Bakar的临界风速预测模型和计算观测数据,应用MATLAB拟合工具箱建立弧形隧道的临界风速模型。利用该模型预测重庆市某公路隧道在发生火灾情况下的临界风速,将预测结果与Wu&Bakar模型和FDS的预测结果进行对比,结果表明,该模型比Wu&Bakar模型更加接近数值模拟的结果。 相似文献
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Full-scale experiment and numerical simulations are carried out on a shelf fire in a storehouse to study the ignition manner, the fire spread and the combustion characteristics. A computational fluid dynamics (CFD) model of fire-driven fluid flow, FDS (Fire Dynamics Simulator), is used to solve numerically a form of the Navier–Stokes equations for fire. Ignition manner experiments with both cigarette ends and lighter are conducted first. Then a full-scale experiment on a shelf fire is performed. The temperatures are measured and the fire growth and spread process is analyzed. A numerical model is used to simulate the experiment; the temperatures, fire growth and heat release rate are studied. In numerical simulations, the grid size resolution is analyzed. The experimental results of temperatures and the fire growth and spread process are compared with the results of numerical simulations. It shows that the numerical results are in good agreement with the experimental results. The chimney effect is also observed in both the experiment and the simulation. These useful data can be helpful in the numerical reconstruction of the whole storehouse fire accident. 相似文献
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利用FDS 建立17 层高层办公楼数值模型,考虑狭缝的小开口流动,耦合了基于开口流动理论的HVAC 模型,研究高层建筑内烟气通过电梯竖井的蔓延过程,得到了高层建筑内烟囱效应诱导的火灾烟气蔓延规律。高层建筑内较低层发生的火灾会显著加热电梯竖井中的气体,形成烟囱效应,高层建筑内部会形成中性面。通过将HVAC 模型与基于标准流量系数的模型进行比较,可以发现这两种方法计算的质量流量相差约1.5 倍。这是由于采用的HVAC 模型并没有考虑狭缝处的开口流动损失。通过进一步修正,取开口损失系数K 值为3.56 能得到较好的模拟结果。 相似文献
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Comparison of FDS Prediction of Smoke Movement in a 10-Storey Building with Experimental Data 总被引:3,自引:0,他引:3
In this study, the Fire Dynamics Simulator (FDS), a computational fluid dynamics (CFD) model developed by National Institute
of Standards and Technology (NIST) is used to simulate fire tests conducted at the National Research Council of Canada (CNRC).
These tests were conducted in an experimental 10-storey tower to generate realistic smoke movement data. A full size FDS model
of the tower was developed to predict smoke movement from fires that originate on the second floor. Three propane fire tests
were modelled, and predictions of O2, CO2 concentrations and temperature on each floor are compared with the experimental data. This paper provides details of the
tests, and the numerical modelling, and discusses the comparisons between the model results and the experiments. The 10-storey
experimental tower was designed to simulate the centre core of high-rise buildings. It includes a compartment and corridor
on each floor, a stair shaft, elevator shaft and service shafts. Three propane fire tests were conducted in 2006 and 2007
to study smoke movement through the stair shaft to the upper floors of the building. The fire was set in the compartment of
the 2nd floor. Thermocouples and gas analyzers were placed on each floor to measure temperature and O2, CO2 and CO concentrations. Comparisons in the fire compartment and floor of fire show that the FDS model gives a good prediction
of temperature and O2 and CO2 concentrations. In the stair shaft and upper floors there are some small differences which are due to the effect of heat
transfer to the stairs that was not considered in the model. Overall the study demonstrates that FDS is capable of modelling
fire development and smoke movement in a high rise building for well ventilated fires. 相似文献