A Virtual Reality based Fire Training Simulator using Fire Dynamics Data

Moohyun Cha,Jaikyung Lee,Byungil Choi,Seonghwan Park,Hanmin Lee,Soonhung Han (사)한국CDE학회 2010 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

A computer-based fire training simulator using virtual reality technology helps the effectiveness of emergency response training for the firefighter or public users. Trainers navigate and experience the simulated fire environments and perform safe and iterative practice using the simulator. To fulfill their purpose, it must recreate fire phenomena with a high degree of accuracy and express them using realistic graphics. Usually, fire engineers develop and utilize CFD (Computational Fluid Dynamics) solvers to simulate fire and fluid behavior with a guaranteed accuracy range. This could provide the precise physical behavior of fluid to the training simulator system. We developed a virtual reality based fire training simulator using these fire dynamics simulation data in order to provide realistic and accurate graphics of fire phenomena. As a result, we could visualize 3D physical quantities related to fire, such as smoke flow, temperature, carbon monoxide, etc., which are calculated from the virtual fire scenario in a road tunnel. Through this system, a trainee was able to navigate and experience physical quantities of fires and a training supervisor could evaluate the training process in an immersive virtual environment.

터널 내화 안전성 확보를 위한 터널 라이닝의 적정 피복두께 및 한계온도 검토를 위한 해석적 연구

장태진,심재원,김기현,하동수,박철우,김승원 한국도로학회 2023 한국도로학회논문집 Vol.25 No.5

fire event in a tunnel can drastically increase the internal temperature, which can significantly affect its structural safety. METHODS : Numerical simulations that consider various fire conditions are more efficient than experimental tests. The fire dynamic simulator (FDS) software, based on computational fluid dynamics (CFD) and developed by the National Institute of Standards and Technology, was used for the simulations. The variables included single and multiple accidents involving heavy goods vehicles carrying 27,000 liters of diesel fuel. Additionally, the concrete material characteristics of heat conductivity and specific heat were included in the analysis. The temperatures of concrete were investigated at various locations, surfaces, and inside the concrete at different depths. The obtained temperatures were verified to determine whether they reached the limits provided by the Fire Resistance Design for Road Tunnel (MOLIT 2021). RESULTS : For a fire caused by 27,000 liters of diesel, the fire intensity, expressed as the heat release rate, was approximately 160 MW. The increase in the carrying capacity of the fire source did not significantly affect the fire intensity; however, it affected the duration of the fire. The maximum temperature of concrete surface in the tunnel was approximately 1400 ℃ at some distance away in a longitudinal direction from the location of fire (not directly above). The temperature inside the concrete was successfully analyzed using FDS. The temperature inside the concrete decreased as the conductivity decreased and the specific heat increased. According to the Fire Resistance Design for Road Tunnel (MOLIT 2021), the internal temperatures should be within 380 ℃ and 250 ℃ for concrete and reinforcing steel, respectively. The temperatures were found to be approximately 380 ℃ and 100 ℃ in mist cases at depths of 5 cm and 10 cm, respectively, inside the concrete. CONCLUSIONS : The fire simulation studies indicated that the location of the maximum temperature was not directly above the fire, possibly because of fire-frame movements. During the final stage of the fire, the location of the highest temperature was immediately above the fire. During the fire in a tunnel with 27,000 liters of diesel, the maximum fire intensity was approximately 160 MW. The capacity of the fire source did not significantly affect the fire intensity, but affected the duration. Provided the concrete cover about 6 cm and 10 cm, both concrete and reinforcing steel can meet the required temperature limits of the Fire Resistance Design for Road Tunnel (MOLIT 2021). However, the results from this study are based on a few assumptions. Therefore, further studies should be conducted to include more specific numerical simulations and experimental tests that consider other variables, including tunnel shapes, fire sources, and locations.

화재 열 유동을 고려한 구조물의 열응력해석

박홍락,강준원,이진우 한국전산구조공학회 2016 한국전산구조공학회논문집 Vol.29 No.4

이 연구는 화재에 노출된 구조물의 역학적 거동을 평가하기 위한 기반연구로서 화재 유동해석과 열응력해석의 통합 프레 임워크를 확립하고 이를 강재와 콘크리트로 이루어진 대표체적에 적용한 결과를 제시하였다. 먼저 Fire Dynamics Simulator(FDS)를 이용해 임의의 화재곡선으로 모델링되는 화원으로부터 구조물 표면까지 유동해석을 실시하였다. 이를 통 해 구조물 표면에서 시간에 따른 온도 분포를 계산하였고, 이 결과를 비선형 열응력해석에 경계조건으로 적용하였다. 이후의 과정은 화재의 성장 또는 감소에 따라 구조물 표면온도의 변화를 반영하는 열전달해석과 구조해석으로 이루어진다. 제시한 통합 프레임워크에 의해 화재 구조해석을 수행한 결과, 강재와 콘크리트의 대표체적 모두 동일한 하중이 작용할 때 상온 조 건에서는 탄성 거동을 보였지만 화재로 인한 온도 조건을 고려할 경우 소성 거동을 보였다. 이는 구조물이 화재에 노출되는 경우 설계하중보다 작은 하중에서도 한계상태에 이를 수 있다는 것을 의미하며, 따라서 원전구조물이나 교량과 같은 중요 사회기반구조물의 설계 시 구조물의 화재거동 평가가 고려되어야 한다고 할 수 있다. In this study, a numerical analysis framework for investigating the nonlinear behavior of structures under fire conditions is presented. In particular, analysis procedure combining fire-driven flow simulation and thermo-mechanical analysis is discussed to investigate the mechanical behavior of fire-exposed representative volume structures made of steel and concrete, respectively. First of all, fire-driven flow analysis is conducted using Fire Dynamics Simulator(FDS) in a rectangular parallelepiped domain containing the structure. The FDS simulation yields the time history of temperature on the surface of the structure under fire conditions. Second, mechanical responses of the fire-exposed structure with respect to prescribed uniformly distributed loads are calculated by a coupled thermo-mechanical analysis using the time-varying surface temperature as boundary conditions. Material nonlinearities of steel and concrete have been considered in the thermo-mechanical analysis. A series of numerical results are presented to demonstrate the feasibility of the multiphysics structural fire analysis for investigating the structural behavior under fire conditions.

화재시뮬레이션

김상문(Sang Moon Kim),윤상열(Sang Youl Yoon),김경천(Kyung Chun Kim) 한국가시화정보학회 2006 한국가시화정보학회지 Vol.4 No.1

Fire simulation has been developed for decades to analyze fire cases and provide a tool to study fundamental fire dynamics and combustion. There are three way of fire simulation which are a full scale simulation, an experimental simulation and a computational simulation. In case of a full scale simulation, because a higher cost, a higher risk, more efforts are needed, a demand for it has been decreased. But recently a demand for an experimental simulation and a computational simulation has been increased. A computational simulation has several advantages; lower cost, short period, many case studies, more visual results, a quantitative result and etc. FDS(Fire Dynamics Simulator) which has been developed in BFRL (Building and Fire Research Laboratory), NIST(National Institute of Standards and Technology) is a popular world wide code for fire simulation. Lack of accurate predictions by the model could lead to erroneous conclusions with regard to fire safety. All results should be evaluated by the informed judgment of the qualified user.

구획화재에서 환기조건의 변화가 화재특성에 미치는 영향 (Part II: 다차원 화재거동)

김종현,고권현,박충화,황철홍 한국화재소방학회 2010 한국화재소방학회논문지 Vol.24 No.5

Multi-dimensional fire dynamics were studied numerically with the change in ventilation conditions in a full-scale ISO 9705 room. Fire Dynamic Simulator (FDS) was used for the identical conditions conducted in previous experiments. Flow rate and doorway width were changed to create over-ventilated fire (OVF) and under-ventilated fire (UVF). From the numerical simulation, it was found that the internal flow pattern rotated in the opposite direction for the UVF relative to the OVF so that a portion of products recirculated to the inside of compartment. Significant change in flow pattern with ventilation conditions may affect changes in the complex process of CO and soot formation inside the compartment due to increase in the residence time of high-temperature products. The fire behavior in the UVF created complex 3D characteristics of species distribution as well as thermal and flow structures. In particular, additional burning near the side wall inside the compartment significantly affected the flow pattern and CO production. The distribution of CO inside the compartment was explained with 3D O2 distribution and flow patterns. It was observed that gas sampling at local positions in the upper layer were insufficient to completely characterize the internal structure of the compartment fire. 실규모 ISO 9705 표준 화재실에서 환기조건 변화에 따른 다차원 화재거동에 관한 수치해석적 연구가수행되었다. 선행된 실험과 동일한 조건에 대하여 FDS(Fire Dynamic Simulator)가 사용되었다. 과환기화재 및 환기부족화재의 발생을 위하여 연료 유량과 출입구의 폭이 변화되었다. 주요 결과로서, 환기부족화재의 내부 유동패턴은 과환기화재와 비교할 때 반대방향을 갖으며, 그 결과 다량의 고온 생성물이 구획내부에서 재순환되는 매우 중요한 특징을 확인하였다. 환기조건에 따른 유동패턴의 변화는 구획 내부에서고온 생성물의 체류시간을 크게 변화시키며, CO 및 그을음의 복잡한 생성과정에 큰 영향을 미칠 수 있다. 환기부족화재는 구획 내부의 열 및 유동구조 뿐만 아니라 화학종의 분포에 관하여 매우 복잡한 3차원 구조를 생성하였다. 특히, 구획 내부의 측면에서 추가적인 반응은 유동패턴 및 CO 생성에 매우 큰 영향을주고 있다. 복잡한 CO의 분포는 3차원 산소 농도의 분포 및 유동 패턴을 통해 체계적으로 분석되었다. 위 결과로 부터 고온 상층부에서 측정된 국부 화학종 농도는 구획 내부의 화재특성을 규명하는데 많은한계가 있음을 확인할 수 있었다.

효율적인 화재안전설계를 위한 축소화재시험기기 연구

류상훈,최백열,박원희 한국화재감식학회 2014 한국화재감식학회 학회지 Vol.5 No.1

The fire accidents having recently occurred are getting more and more larger and causing lots of damage in terms of property loss and casualties increase, so there is in need of technical fire safety development like comprehensive prevention solution in order to effectively prevent. In this study, we want to present an efficient method of fire safety design through FDS (Fire Dynamics Simulator) modelling techniques without full-scale fire test. So in this time, we should be developing optimization and test process to obtain fire pyrolysis properties for fire FDS firstly. Therefore, we want to find out on this paper how to analysis to predict the fire risk to fully understanding about fire phenomenon, real scale fire test should performed, but , because of cost and reproducibility, fire simulation usage has been increasing, and fire property of construction and living material during pyrolysis procedure is required for assure accuracy of fire simulation. However, those fire properties have difficulty about measurement of necessity data for reliability improvement fire simulation or fire properties during pyrolysis. Testing equipments for each properties occur a lots of cost and time. So to develop for, not the exist testing method, but the advanced fire properties computable All-in-one type testing equipment, reducing cost and reliability should be assured.

건물 내 고체연료 화재에 대한 설계화재곡선 예측성능 평가

백빛나,오창보 한국화재소방학회 2019 한국화재소방학회논문지 Vol.33 No.2

The prediction performance of design fire curves was evaluated using a Fire dynamics simulator (FDS) for a solid fuelfire in a building space by comparing the results with experimental data. EDC 2-step mixing controlled combustion modelwas used in the FDS simulations and the previously suggested 2-stage design fire (TDF), Quadratic and Exponential designfire curves were used as the FDS inputs. The simulation results showed that smoke propagation in the building space wassignificantly affected by the design fire curves. The predictions of simulations using design fire curves for the experimentaltemperatures in the building space were reasonable, but the TDF was found to be the most acceptable for predictingtemperature. The predictions with each design fire curve of species concentrations showed insufficient agreement with theexperiments. This suggests that the combustion model used in this study was not optimized for the simulation of a solidfuel fire, and additional studies will be needed to examine the combustion model on the FDS prediction of solid fires. 건물형태의 공간 내에서 발생한 고체연료 화재에 대해 Fire dynamics simulator (FDS)을 이용하여 설계화재곡선의예측성능을 실험결과와 비교하여 평가하였다. FDS의 연소모델로서는 EDC 2-step mixing controlled를 적용하였으며검토된 설계화재곡선들은 기존 연구들에서 제안한 2-stage design fire (TDF) 곡선, Quadratic 및 Exponential design fire곡선들이다. 시뮬레이션 결과는 건물 내 연기 전파과정이 설계화재곡선에 많은 영향을 받는 것을 확인하였다. 설계화재곡선을 이용한 시뮬레이션은 건물 내 실험온도결과에 대해 합리적으로 예측하고 TDF가 가장 온도를 무난하게예측하는 것을 확인하였다. 그리고 각 설계화재곡선의 화학종 농도에 대한 예측은 실험과 충분히 예측하지 못하는것을 확인하였다. 이점은 본 연구에서 사용한 연소모델은 고체연료 화재에 대한 시뮬레이션에 적합하지 않음을 나타내며 고체연료의 예측에 대한 FDS 연소모델에 대한 연구가 추가적으로 필요해 보인다.

구획실 내 액체 풀화재에 대한 디자인 화재곡선 적용 연구

백빛나,오창보,이의주,남동군 한국화재소방학회 2017 한국화재소방학회논문지 Vol.31 No.4

In this study, new design fire curves were suggested for the utilization in fire simulations. Numerical simulations withthe Fire Dynamics Simulator (FDS) were performed for the n-octane and n-heptane pool fires in the ISO 9705 compartmentto evaluate the prediction performance of the previous quadratic, exponential design fire curves and newly suggested ones. The numerical results were compared with the experimental temperature and concentrations of O2 and CO2. The numericalresults with the previous quadratic and exponential curves showed slow increase and decrease trend than experiments. However, the numerical results with the newly suggested 2 design fire curves showed more similar variation trend intemperature, O2 and CO2 concentrations than the quadratic and exponential curves. It was found that the newly suggesteddesign fire curves can be possibly used in the numerical simulation of fires in a practical respect. 본 연구에서는 화재 수치계산에 사용하기 위한 새로운 디자인 화재곡선을 제안하였다. ISO 9705 구획실 내 형성된 옥탄과 헵탄연료 풀화재에 대해 기존에 제안된 2차곡선과 지수함수 형태의 디자인 화재곡선과 새롭게 제안된 디자인 화재곡선을 적용한 Fire Dynamics Simulator (FDS) 수치계산을 수행하였다. 여기서 얻어진 수치계산 결과와 실험에서 측정한 온도와 O2, CO2 변화와 비교하여 디자인 화재곡선의 예측성능을 평가하였다. FDS 계산과 실험결과의비교를 통해 2차곡선과 지수함수 형태의 디자인 화재곡선을 적용했을 때는 측정된 온도보다도 훨씬 완만하게 증가하고 감소하는 것을 알 수 있었다. 그러나 새로 제안한 2가지 디자인 화재곡선은 기존 디자인 화재곡선보다는 급격히 상승하여 실험결과에 좀 더 유사하게 나타나는 것으로 확인되어 실용적 관점에서 수치계산에 활용될 수 있음을확인하였다.

CFD를 이용한 서문시장 발화지점 분석

오원신 한국화재감식학회 2017 한국화재감식학회 학회지 Vol.8 No.1

It is important to investigate cause and origin of fires to reduce damage and casualties. The difficulty of determining them has occurred because fires often destroy the key evidence. In this study, CFD-based Fire Dynamics Simulator (FDS) was used to reconstruct fire scene and presume origin of the Seomun market fire that occurred on November 30, 2016, in Daegu Metropolitan City. Comparing result of simulation with testimony of first witness and fire-fighters, it was estimated that the fire occurred outside of the market and sprinkler system worked. First-aid fire fighting was unsuccessful because of retardation of smoke detector activation. Fire-spreading into the building was delayed by the sprinkler system operation. And, it was found that tent covered on the stall accelerated fire spread.

화재시뮬레이션(FDS)을 활용한 제천스포츠센터 화재확산경로 추정에 관한 연구

최윤주(Yunju Choi),김윤성(Yunseong Kim),진승현(Seunghyeon Jin),구인혁(Inhyuk Koo),권영진(Youngjin Kwon) 한국방재학회 2023 한국방재학회논문집 Vol.23 No.2

2017년 제천스포츠센터 화재로 인하여 약 80명의 사상자가 발생하였다. 특히 2층과 3층에서 화재피해 형태가 상이하게 발생해 일반적인 화재사례와 차이점이 나타났다. 이후 발간된 화재백서 및 보고서 등에서는 주요 화재확산경로를 화물용 승강기로 추정하고 있다. 그러나 화재로 인한 소손 피해, CCTV 및 재실자 증언 등의 자료에 따르면 화물용 승강기가 2층과 3층에서 상이한 피해를 야기한 화재확산경로가 아닐 수 있다는 것을 시사한다. 따라서 본 연구에서는 화재확산 경로를 명확히 추정하기 위하여 화재사례 및 화재시뮬레이션을 비교하였다. 그 결과 화물용 승강기보다 주 계단이 주요 화재확산경로로서 더욱 신빙성이 있는 것으로 나타났다. In 2017, a fire at the Jecheon Sports Center resulted in approximately 80 casualties. Interestingly, the extent of fire damage on the second and third floors differed from the general type of fire damage. The white papers and reports of the Jecheon Fire Department indicated that the primary spread path of the fire was a freight elevator. However, analysis of the damage caused, CCTV footage, and victim testimonies suggested that the freight elevator may not have been the primary fire spread path on the second and third floors. Therefore, further investigation was needed to identify the cause of the fire. In this study, fire simulations were conducted using a Fire Dynamics Simulator (FDS) and compared with actual fire cases, which enabled us to predict the fire spread path accurately. It was found that the main stairway was more likely to have been the main fire spread path than the freight elevator.