450 Numerical Simulation of Fire Smoke in a Small Cross Sectional Tunnel

2005 ◽  
Vol 2005.2 (0) ◽  
pp. 365-366
Author(s):  
Tomoki KIKUMOTO ◽  
Nobuyoshi KAWABATA ◽  
Masahisa YAMADA
2018 ◽  
Vol 82 ◽  
pp. 82-98 ◽  
Author(s):  
Xinxin Guo ◽  
Xuhai Pan ◽  
Zhilei Wang ◽  
Juan Yang ◽  
Min Hua ◽  
...  

2012 ◽  
Vol 58 (5) ◽  
pp. 57-67 ◽  
Author(s):  
Hua QIU ◽  
Yoshiyuki IEMOTO ◽  
Shuichi TANOUE ◽  
Hideyuki UEMATSU

2020 ◽  
Vol 29 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Jamal Zaini ◽  
Agus Dwi Susanto ◽  
Erlang Samoedro ◽  
Vonni Christiana Bionika ◽  
Budhi Antariksa

BACKGROUND Indonesia forest fire in 2015 emitted a huge amount of pollutants into the air. This study was aimed to assess the health consequences of forest fire smoke in healthy residents in Riau during forest fire disaster in 2015. METHODS This cross-sectional study was performed in healthy residents who lived in Pekanbaru, Riau Province, Sumatera, for at least 6 months during forest fire disaster in 2015, and data were taken in October 2015. Questionnaires consisting of respiratory and non-respiratory symptoms were collected. Lung function was assessed by spirometry (MIR II Spirolab™ spirometer, Medical International Research, Italy) and exhaled carbon monoxide (CO) was assessed using piCO+ Smokerlyzer®. Heart rate at rest and oxygen saturation in the room air were measured using Onyx 9591 Pulse Oximeter®. RESULTS A total of 89 subjects were mostly female (75.3%), housewife (37.7%), nonsmoker (86.5%) with mean age of 38.9 years old. The non-respiratory and respiratory symptoms were reported in 84.7% and 71.4% subjects, respectively. Lung function was impaired in 72.6% subjects, mostly with mild obstruction and mild restriction. Exhaled CO was highly detected over normal values (mean [standard deviation] = 32.6 [9.97] ppm) with predicted carboxyhemoglobin (COHb) of 5.74 (1.56). CONCLUSIONS Forest fire smoke exposure increased the respiratory and nonrespiratory symptoms among healthy individuals, which showed impairment in lung function, exhaled CO, and predicted COHb. Long term health effects on healthy individuals exposed to forest fire smoke warrant further evaluation.


2019 ◽  
Vol 6 (1) ◽  
pp. 19-30
Author(s):  
Dong-Ho Kim ◽  
Yong-Muk Kim ◽  
Kyu-Nam Hwang ◽  
Su-Hyun Yang

Author(s):  
Shiva P Pudasaini ◽  
Yongqi Wang ◽  
Kolumban Hutter

This paper presents a new model and discussions about the motion of avalanches from initiation to run-out over moderately curved and twisted channels of complicated topography and its numerical simulations. The model is a generalization of a well established and widely used depth-averaged avalanche model of Savage & Hutter and is published with all its details in Pudasaini & Hutter (Pudasaini & Hutter 2003 J. Fluid Mech. 495 , 193–208). The intention was to be able to describe the flow of a finite mass of snow, gravel, debris or mud, down a curved and twisted corrie of nearly arbitrary cross-sectional profile. The governing equations for the distribution of the avalanche thickness and the topography-parallel depth-averaged velocity components are a set of hyperbolic partial differential equations. They are solved for different topographic configurations, from simple to complex, by applying a high-resolution non-oscillatory central differencing scheme with total variation diminishing limiter. Here we apply the model to a channel with circular cross-section and helical talweg that merges into a horizontal channel which may or may not become flat in cross-section. We show that run-out position and geometry depend strongly on the curvature and twist of the talweg and cross-sectional geometry of the channel, and how the topography is shaped close to run-out zones.


2012 ◽  
Vol 256-259 ◽  
pp. 1396-1401
Author(s):  
Da Hui Sun ◽  
Hui Yang ◽  
Yan Jun Xing

When highway tunnel is on fire, obstruction of vehicles in the tunnel have certain effects on the spread of fire smoke and critical velocity. This paper made CFD studies on the critical velocities when the blockage is located in the upstream flow of the fire smoke. The effect of the distance between fire source and blockage as well as the dimension ratio was analyzed. The numerical simulation results show that the critical velocity in upstream obstructed tunnel is smaller than that in empty tunnel and the critical velocity increases with the distance between the blockage and the fire source. The critical velocity increases with the heat release rate and decreases with the dimension ratio. The calculating model for critical velocity of empty tunnel was modified to adapt to obstructed tunnel.


Mechanik ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 412-414
Author(s):  
Jan Burek ◽  
Rafał Flejszar ◽  
Barbara Jamuła

The analytical and numerical model of the cross-section of the machined layer in the process of milling of concave rounding is presented. Simulation tests were carried out to determine the cross-sectional area of the cutting layer. A strategy has been developed that allows to increase the stability of the cross-section area of the cutting layer when the mill enters the inner corner area.


2021 ◽  
Vol 303 ◽  
pp. 01042
Author(s):  
Min Xu ◽  
Pengyi Bu ◽  
Lin Xin ◽  
Chao Li ◽  
Limin Han ◽  
...  

With the rapid development of economy, the number of buses and bus fire increases. This paper takes bus as the research object and uses software FDS to explore the fire smoke spread under different fire power conditions. The results show that: with the increase in fire power, the smoke in the compartment rapidly accumulates, and the heating rate is also accelerated. The visibility decreases with the diffusion of smoke in the compartment. The CO concentration increases with time. The greater the fire power, the higher the temperature which will eventually stabilize. Only the concentration of smoke near the entrance will be slightly reduced. This is also conducive to the escape of people inside the car.


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