A Numerical Study of the Fire-Extinguishing Performance of Ultrafine Water Mist in Small Scale Tunnel Space

2013 ◽  
Vol 444-445 ◽  
pp. 1555-1558
Author(s):  
Tian Shui Liang ◽  
Jing Jing Yu ◽  
Guan Peng Lu ◽  
Xiang Li ◽  
Wei Zhong ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Study ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Flow Behavior ◽  
Water Mist ◽  
Small Scale ◽  
Dense Gas ◽  
Fire Extinguishing

CFD simulation study on the fire-extinguishing performance of ultra-fine water mist (UFM) and its flow behavior in a small scale tunnel. Numerical simulation using dense gas model were carried outIt is discorvered that simulation shows that the larger size of fire is more difficult to extinguish in tunhenel space; and that the effect of obstruction in extinguishing efficiency depends on the location of obstruction.

Numerical Study of the Pressure Drop in a Flame Arrestor Using a Porous Media Model

2020 ◽  
Author(s):  
Hoden A. Farah ◽  
Frank K. Lu ◽  
Jim L. Griffin
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Small Scale ◽  
Forchheimer Equation ◽  
Flow Equations ◽  
Numerical Studies ◽  
Porous Media Model ◽  
Empirical Coefficients

Abstract A numerical study of the flow characteristics of a crimped flame arrestor element was conducted using a porous media model. The porous zone was modeled using the Forchheimer equation. The Forchheimer equation was incorporated into the governing conservation equations as a momentum sink. A small-scale crimped flame arrestor element was tested to determine the empirical coefficients in the Forchheimer equation. The numerical simulation result using this porous media model was verified using experimental data. The flow characteristics of a four-inch detonation flame arrestor with the same crimp design as the small-scale sample, was simulated using the porous media model. The numerical simulation flow data were compared against experimental values and agreed to within five percent. The method used to determine the Forchheimer coefficients and the experimental test setup are described in detail. The application of the Forchheimer equation into the governing flow equations is presented. The challenges and limitation of numerical studies in flame arrestors applications are discussed. The simplification gained by using the porous media model in flame arrestor numerical studies is presented.

scholarly journals A Numerical study of the Fire-extinguishing Performance of Water Mist in an Opening Machinery Space

2012 ◽  
Vol 31 ◽  
pp. 734-738 ◽  
Author(s):  
Tianshui Liang ◽  
Siuming Lo ◽  
Xishi Wang ◽  
Guangxuan Liao
Keyword(s):  
Numerical Study ◽  
Water Mist ◽  
Fire Extinguishing ◽  
Machinery Space

Experimental and Numerical Study on the Suppression of Pool Fire with Water Mist

2013 ◽  
Vol 790 ◽  
pp. 686-689
Author(s):  
Chen Jian ◽  
Xu Yan Ying ◽  
Wang Yan Sheng
Keyword(s):  
Systems Engineering ◽  
Numerical Study ◽  
Fire Suppression ◽  
Inhibitory Effect ◽  
Water Mist ◽  
Pool Fire ◽  
Optimized Design ◽  
Operating Pressure ◽  
Fire Extinguishing ◽  
Oil Pool

The objective of this work is to investigate the diesel analog pool fire with water mist .For this purpose, a series of water mist fire suppression experiment are carried out by changing the nozzle operating pressure, the source of fire power, opening and closing the exhaust fan to analyze the inhibitory effect of water mist to oil pool fire in the enclosed compartment of 5.0m × 5.0m × 3.0m. The results shows that extinguishing efficiency first increases and then decreases when the nozzle operating pressure increases from 8MPa to 12MPa, reaching the highest efficiency at 10MPa; increasing the power of the source of fire, the burning speed increases and the water mist fire extinguishing efficiency decreases; fresh oxygen coming in when smoke exhaust fan is turned on and water mist fire suppression efficiency decreases. Using FDS to simulate the water mist extinguishing oil pool fire, the predict temperature field and extinguishing time are basically consistent with the experimental results. In the actual applications of water mist fire suppression systems engineering, we can use the FDS field simulation methods to predict the characteristic parameters variation of the fire fighting fire temperature and component concentration, which is significant to the fire extinguishing system optimized design.

Numerical Simulation and Research of Pool Fire Suppressed by Water Mist in the Engineroom of a Ship

2010 ◽  
Vol 29-32 ◽  
pp. 651-657 ◽  
Author(s):  
Jian He Zhao ◽  
Ye Gao ◽  
Hong Mei Wu
Keyword(s):  
Numerical Simulation ◽  
Oxygen Content ◽  
Large Scale ◽  
Cone Angle ◽  
Water Mist ◽  
Fire Fighting ◽  
Pool Fire ◽  
Cooling Effect ◽  
Small Scale ◽  
Spray Cone

Ship engineroom fire is one of the most common and serious disasters in shipwrecks. It has become a hotspot of research to use water mist system to extinguish engineroom fire efficiently in the ship fire fighting field. In this paper, using Fluent to simulate water mist suppressing engineroom fire on the conditions of different fire scales, droplet diameters, spray cone angles and spray pressures. Research indicates that: large scale fires are more easily suppressed than small scale fires by water mist in the enclosure engineroom; the droplets of water mist should be neither too big nor too small, or else it would go against fire fighting. It is pointed out that the droplets should be in the range of 200 μm to 400 μm; the smaller cone angle nozzle can guarantee a high flame cooling effect; the increase of spray pressure can enhance the flame cooling effect, but probably of only marginal help in reducing the oxygen content.

scholarly journals Numerical simulation study of composite solid propellant small scale gap test

AIP Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 015051
Author(s):  
Hong-fu Qiang ◽  
Yu-xiang Liu ◽  
Du-dou Wang ◽  
Xue-ren Wang ◽  
Biao Geng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Study ◽  
Solid Propellant ◽  
Small Scale ◽  
Composite Solid Propellant ◽  
Gap Test ◽  
Composite Solid

Numerical Study of Oil Slug Mobilization in a Capillary Tube

2010 ◽  
Author(s):  
Yihe Zhang ◽  
Liming Dai ◽  
Junya Luo
Keyword(s):  
Numerical Simulation ◽  
Simulation Study ◽  
Pressure Difference ◽  
Capillary Tube ◽  
Numerical Study ◽  
Surface Shape ◽  
Simplified Model ◽  
Residual Oil ◽  
Capillary Tubes ◽  
Inner Surface

This research investigates the effects of pore dimensions and smoothness on the mobilization of residual oil trapped inside pore structures. A model of water-filled uniform capillary tube with an oil slug trapped inside is employed as a simplified model for numerical simulation study. Pressure difference between two ends of the tube is being measured. The influence of the inner surface shape of the tube is mostly considered in this research. Based on the measurements of the capillary tubes used in experiments, a sine curved shape is employed to represent the inner surface of the capillary tube. Series of results have been obtained from the simulation. According to the results, the pressure difference required to mobilize the oil slug is inversely proportional to the smoothness of the tube inner surface shape.

A Numerical Study Onfire Suppression of Water Mist in Microgravity

2014 ◽  
Vol 1016 ◽  
pp. 819-823
Author(s):  
Xue Han ◽  
Jun Qin ◽  
Jun Jun Tao ◽  
Ming Hui Feng
Keyword(s):  
Flow Rate ◽  
Numerical Study ◽  
Fire Suppression ◽  
Water Flow Rate ◽  
Simulation Method ◽  
Critical Value ◽  
Water Mist ◽  
Dominant Mechanism ◽  
Effect Of Water ◽  
Fire Extinguishing

Water mist technology has been developed and regarded as a promising substitute fire-extinguishing agent in spacecraft. In this paper, a numerical simulation method is introduced to investigate the effect of water mist size, velocity and flow rateon the fire suppressionefficiencyin microgravity. The fire extinguishing efficiency is better for the finer water mist in microgravity due to better heat transfer and more rapid vaporization. The evaporation cooling is the dominant mechanism of fire suppression in microgravity.As for the water mist velocity, the performance of fire suppression is affected slightly in microgravity. The results on the effect of water flow rate show that the flow rate should be higher than a critical value to suppress the fire effectively.

NUMERICAL SIMULATION STUDY ON BIONIC MUCUS DRAG REDUCTION OF UNDERWATER VEHICLE

2020 ◽  
Vol 47 (4) ◽  
pp. 371-385
Author(s):  
Kaisheng Zhang ◽  
Chaofan Ma ◽  
Baocheng Zhang ◽  
Bo Zhao ◽  
Qiang Wang
Keyword(s):  
Numerical Simulation ◽  
Drag Reduction ◽  
Simulation Study ◽  
Underwater Vehicle
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