The Fire Dynamics Simulator(FDS)is widely used for fire simulation but faces scalability challenges due to its limited grid partitioning capabilities.To address this issue,we propose Para-FDS,a scalable multilevel par...The Fire Dynamics Simulator(FDS)is widely used for fire simulation but faces scalability challenges due to its limited grid partitioning capabilities.To address this issue,we propose Para-FDS,a scalable multilevel parallel scheme for accelerating FDS targeted at multicore architectures.Para-FDS integrates three key optimizations:(1)an adaptive grid partitioning algorithm to enhance scalability,(2)a communication localization optimization approach to reduce overhead between computing nodes,and(3)a NUMA-aware process mapping strategy to improve core utilization within Non-Uniform Memory Access(NUMA)architecture.Implemented on the Tianhe next-generation supercomputer,Para-FDS achieves a speedup of up to 214×on a practical example.It further reduces communication overhead by up to 38%and execution time by up to 22%,significantly improving FDS scalability and efficiency.展开更多
The paper presents the analysis of a human evacuation from a higher education building located in Iassy,Romania,by means of engineering techniques to approach fire safety.Because in Romania(as in other European countr...The paper presents the analysis of a human evacuation from a higher education building located in Iassy,Romania,by means of engineering techniques to approach fire safety.Because in Romania(as in other European countries)fire safety design of buildings is prescriptive and not performance-based,a fire safety engineering approach arouse great interest in many countries such as the U.S.A.,Australia,New Zealand,England,Sweden,Finland,etc.This paper is based on the assumption of starting a fire in the space of a hall for festivities,located on the ground floor of the building,near two human evacuation routes;We consider two building evacuation scenarios:two exits and,respectively,just one exit(assuming that the second would be accidentally blocked).展开更多
Moving IBM （immersed boundary method） is applied to analyze the relative motion of railway car flow in the single-bore subway tunnel with vertical ventilation. The tested car body is modeled by cylinder type body. T...Moving IBM （immersed boundary method） is applied to analyze the relative motion of railway car flow in the single-bore subway tunnel with vertical ventilation. The tested car body is modeled by cylinder type body. The subway tunnel is assumed to be the single-car-passing straight type （single-bore tunnel）. The modeled car is relatively moved forward. On the other hand, the tunnel and vertical ventilation are fixed. The momentum equations are solved by LES （large eddy simulation） method. The initial condition of fluid in the subway tunnel is stationary. The Reynolds number is 1,500 based on the cylinder radius. The turbulent flow field in the subway tunnel and vertical ventilation shaft are to be qualitatively investigated.展开更多
A comprehensive description of the key factors affecting evacuations at fire scenes is necessary for accurate simulations. An agent-based simulation model which incorporates the fire scene and the building geometry is...A comprehensive description of the key factors affecting evacuations at fire scenes is necessary for accurate simulations. An agent-based simulation model which incorporates the fire scene and the building geometry is developed using a fire dynamics simulator （FDS） based on the computational fluid dynamics and geographic information system （GIS） data to model the occupant response, The building entities are generated for FDS simulation while the spatial analysis on GIS data represents the occupant＇s knowledge of the building. The influence of the fire is based on a hazard assessment of the combustion products. The agent behavior and decisions are affected by environmental features and the fire field. A case study demonstrates that the evacuation model effectively simulates the coexistence and interactions of the major factors including occupants, building geometry, and fire disaster during the evacuation. The results can be used for the assessments of building designs regarding fire safety.展开更多
A numerical simulation study was conducted to analyze flashover in a full-scale aircraft cargo compartment,utilizing FDS(Fire Dynamics Simulator)and PyroSim(visual modeling)software.The study aims to:(i)examine how va...A numerical simulation study was conducted to analyze flashover in a full-scale aircraft cargo compartment,utilizing FDS(Fire Dynamics Simulator)and PyroSim(visual modeling)software.The study aims to:(i)examine how varying heat release rates(HRR),pressures,and vent sizes influence the hot gas layer temperature during flashover in confined spaces,and(ii)establish a semi-empirical model to predict flashover.Experimental results indicate that when the vent size is 1.86 m×1.06 m and the pressure is 101 kPa,the minimum hot gas layer temperature required to trigger flashover is approximately 410℃.When the pressure is reduced to 80 kPa and 60 kPa,the critical temperature increases to approximately 436℃ and 460℃,respectively.These findings provide critical temperature benchmarks for predicting flashover in aircraft cargo fires.Furthermore,a semi-empirical engineering calculation model was developed to predict the hot gas layer temperature under various conditions during flashover.Validation against experimental data from the literature demonstrated good agreement(deviation of≈20%),confirming the model's applicability in diverse scenarios.展开更多
基金supported by the Major Program of Xiangjiang Laboratory(No.22XJ01004)NSFC-FDCT(62361166662)+7 种基金National Key R&D Program of China(2023YFC3503400,2022YFC3400400)The Innovative Research Group Project of Hunan Province(2024JJ1002)Top 10 Technical Key Project in Hunan Province(2023GK1010)Key R&D Program of Hunan Province(2023GK2004,2023SK2059,2023SK2060)Key Technologies R&D Program of Guangdong Province(2023B1111030004)The National Natural Science Foundation of China(41875121,42305170),and the Natural Science Foundation of Hunan Province(2023JJ40678)The Funds of State Key Laboratory of Chemo/Biosensing and Chemometricsthe National Supercomputing Center in Changsha(http://nscc.hnu.edu.cn/),and Peng Cheng Lab.
文摘The Fire Dynamics Simulator(FDS)is widely used for fire simulation but faces scalability challenges due to its limited grid partitioning capabilities.To address this issue,we propose Para-FDS,a scalable multilevel parallel scheme for accelerating FDS targeted at multicore architectures.Para-FDS integrates three key optimizations:(1)an adaptive grid partitioning algorithm to enhance scalability,(2)a communication localization optimization approach to reduce overhead between computing nodes,and(3)a NUMA-aware process mapping strategy to improve core utilization within Non-Uniform Memory Access(NUMA)architecture.Implemented on the Tianhe next-generation supercomputer,Para-FDS achieves a speedup of up to 214×on a practical example.It further reduces communication overhead by up to 38%and execution time by up to 22%,significantly improving FDS scalability and efficiency.
文摘The paper presents the analysis of a human evacuation from a higher education building located in Iassy,Romania,by means of engineering techniques to approach fire safety.Because in Romania(as in other European countries)fire safety design of buildings is prescriptive and not performance-based,a fire safety engineering approach arouse great interest in many countries such as the U.S.A.,Australia,New Zealand,England,Sweden,Finland,etc.This paper is based on the assumption of starting a fire in the space of a hall for festivities,located on the ground floor of the building,near two human evacuation routes;We consider two building evacuation scenarios:two exits and,respectively,just one exit(assuming that the second would be accidentally blocked).
文摘Moving IBM （immersed boundary method） is applied to analyze the relative motion of railway car flow in the single-bore subway tunnel with vertical ventilation. The tested car body is modeled by cylinder type body. The subway tunnel is assumed to be the single-car-passing straight type （single-bore tunnel）. The modeled car is relatively moved forward. On the other hand, the tunnel and vertical ventilation are fixed. The momentum equations are solved by LES （large eddy simulation） method. The initial condition of fluid in the subway tunnel is stationary. The Reynolds number is 1,500 based on the cylinder radius. The turbulent flow field in the subway tunnel and vertical ventilation shaft are to be qualitatively investigated.
基金the key Technologies Research and Development Pro-gram of the Eleventh Five-Year Plan of China (No. 2006BAK01A02)
文摘A comprehensive description of the key factors affecting evacuations at fire scenes is necessary for accurate simulations. An agent-based simulation model which incorporates the fire scene and the building geometry is developed using a fire dynamics simulator （FDS） based on the computational fluid dynamics and geographic information system （GIS） data to model the occupant response, The building entities are generated for FDS simulation while the spatial analysis on GIS data represents the occupant＇s knowledge of the building. The influence of the fire is based on a hazard assessment of the combustion products. The agent behavior and decisions are affected by environmental features and the fire field. A case study demonstrates that the evacuation model effectively simulates the coexistence and interactions of the major factors including occupants, building geometry, and fire disaster during the evacuation. The results can be used for the assessments of building designs regarding fire safety.
文摘A numerical simulation study was conducted to analyze flashover in a full-scale aircraft cargo compartment,utilizing FDS(Fire Dynamics Simulator)and PyroSim(visual modeling)software.The study aims to:(i)examine how varying heat release rates(HRR),pressures,and vent sizes influence the hot gas layer temperature during flashover in confined spaces,and(ii)establish a semi-empirical model to predict flashover.Experimental results indicate that when the vent size is 1.86 m×1.06 m and the pressure is 101 kPa,the minimum hot gas layer temperature required to trigger flashover is approximately 410℃.When the pressure is reduced to 80 kPa and 60 kPa,the critical temperature increases to approximately 436℃ and 460℃,respectively.These findings provide critical temperature benchmarks for predicting flashover in aircraft cargo fires.Furthermore,a semi-empirical engineering calculation model was developed to predict the hot gas layer temperature under various conditions during flashover.Validation against experimental data from the literature demonstrated good agreement(deviation of≈20%),confirming the model's applicability in diverse scenarios.
