Attenuation of thermal radiation through water mist

2017 ◽  
Vol 37 (1) ◽  
pp. 18-24
Author(s):  
Dalibor Balner ◽  
Karla Barcova
Keyword(s):  
Thermal Radiation ◽  
Water Mist

Effect of soot on thermal radiation shielding performance of water mist

2021 ◽  
Vol 123 ◽  
pp. 103363
Author(s):  
Hiroki Gonome ◽  
Yuto Takagi ◽  
Taichi Nagao ◽  
Mizuho Ono
Keyword(s):  
Thermal Radiation ◽  
Water Mist ◽  
Radiation Shielding

Experimental and numerical study on attenuation of thermal radiation from large-scale pool fires by water mist curtain

2015 ◽  
Vol 33 (4) ◽  
pp. 269-289 ◽  
Author(s):  
Pei Zhu ◽  
Xishi Wang ◽  
Zhigang Wang ◽  
Haiyong Cong ◽  
Xiaomin Ni
Keyword(s):  
Thermal Radiation ◽  
Large Scale ◽  
Numerical Study ◽  
Water Mist ◽  
Pool Fires

scholarly journals Numerical Study on the Attenuation Effect of Water Mist on Thermal Radiation

2020 ◽  
Vol 34 (4) ◽  
pp. 7-12
Author(s):  
Gwon Hyun Ko
Keyword(s):  
Thermal Radiation ◽  
Droplet Size ◽  
Numerical Study ◽  
Water Mist ◽  
Spray Angle ◽  
Fire Dynamics ◽  
Radiation Attenuation ◽  
Attenuation Effect ◽  
Spray Droplets ◽  
Hot Surface

A numerical study was conducted to investigate the effects of the spray characteristics of water mist on the attenuation of thermal radiation. The attenuation process of the thermal radiation, generated from a hot surface panel, passing through the water mist was calculated via Fire Dynamics Simulator (FDS), and the effects of the flow rate, droplet mean diameter, and spray injecting angle of the water mist were analyzed. The results indicated that the increase in flowrate and decrease in droplet size led to an increase in the attenuation of thermal radiation. As the thermal radiation passed through the spray droplets, the effect of the spatial distribution of spray droplets was verified by calculating the thermal radiation attenuation at different spray injecting angles. The results indicated that the radiation attenuation increases as the spray angle increases. This implies that a wider distribution of spray droplets, irrespective of the droplet size and flowrate, increases the attenuation effect on thermal radiation.

scholarly journals Experimental Study on Thermal Radiation Attenuation Using Water Mist of Twin-fluid Atomizer

2021 ◽  
Vol 35 (4) ◽  
pp. 24-32
Author(s):  
Jae Geun Jo ◽  
Chi Young Lee
Keyword(s):  
Thermal Radiation ◽  
Water Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Water Flow Rate ◽  
Water Mist ◽  
Air Flow Rate ◽  
Radiation Attenuation ◽  
Rate Condition ◽  
Flow Rates

In this study, the thermal radiation attenuation performance of water mist was investigated using twin-fluid atomizers. The water and air flow rates of Small atomizer were 36~105 g/min and 10~30 L/min, whereas those of Large atomizer were 37~300 g/min and 20~60 L/min, respectively. In the present experimental range, the thermal radiation attenuation of Small atomizer and Large atomizer were 6.1~11.9% and 5.2~14.6%, respectively. With the increase in water and air flow rates, the thermal radiation attenuation increased, and under similar water and air flow rate conditions, Small atomizer showed higher thermal radiation attenuation than Large atomizer. Based on the present experimental data, it was found that the air (gas) discharge area is a potentially important factor in determining the thermal radiation attenuation performance. Additionally, through the analysis of thermal radiation attenuation per unit water flow rate, it was confirmed that the twin-fluid atomizer can result in higher thermal radiation attenuation than the single-fluid atomizer under the same water flow rate condition.

scholarly journals Examination on Effects of Spray Characteristics of Water Mist on Thermal Radiation Attenuation Using Fire Dynamics Simulator

2021 ◽  
Vol 35 (1) ◽  
pp. 1-10
Author(s):  
Jae Geun Jo ◽  
Chi Young Lee
Keyword(s):  
Numerical Simulation ◽  
Thermal Radiation ◽  
Droplet Size ◽  
Flow Rate ◽  
Water Mist ◽  
Spray Angle ◽  
Fire Dynamics ◽  
Spray Characteristics ◽  
Radiation Attenuation ◽  
Fire Dynamics Simulator

In this study, numerical simulations to investigate the effects of the spray characteristics of water mist on thermal radiation attenuation were performed using fire dynamics simulator (FDS). The droplet size, flow rate, and spray angle of the water mist were 100-300 µm, 1-3 L/min, and 60-180°, respectively. As the droplet size decreased and flow rate increased, the thermal radiation attenuation increased. When the spray angles decreased and increased behind the near nozzle center and behind a certain remote distance from the nozzle center, respectively, the thermal radiation attenuation increased. The peak thermal radiation attenuation increased with decreases in droplet size and spray angle and an increase in flow rate, whereas the average thermal radiation attenuation increased with a decrease in droplet size and increases in flow rate and spray angle. Under the numerical simulation conditions of this study, the peak and average thermal radiation attenuations were significantly altered by the ratios of droplet size and flow rate and by that of flow rate, respectively. However, their variations with the ratio of spray angle were the smallest.

The interaction of thermal radiation and water mist in fire suppression

2004 ◽  
Vol 39 (1) ◽  
pp. 41-66 ◽  
Author(s):  
Wenhua Yang ◽  
Terry Parker ◽  
H.D. Ladouceur ◽  
Robert J. Kee
Keyword(s):  
Thermal Radiation ◽  
Fire Suppression ◽  
Water Mist ◽  
In Fire

Characterizing the convective heat exchange with plastic shading nets under natural arid conditions

2019 ◽  
pp. 11-20
Author(s):  
Ahmed M Abdel-Ghanya ◽  
Ibrahim M Al-Helal
Keyword(s):  
Wind Speed ◽  
Thermal Radiation ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Convective Heat Exchange ◽  
Radiative Properties ◽  
Wooden Frame ◽  
Arid Conditions ◽  
Air Temperatures ◽  
Radiation Fluxes

Plastic nets are extensively used for shading purposes in arid regions such as in the Arabian Peninsula. Quantifying the convection exchange with shading net and understanding the mechanisms (free, mixed and forced) of convection are essential for analyzing energy exchange with shading nets. Unlike solar and thermal radiation, the convective energy, convective heat transfer coefficient and the nature of convection have never been theoretically estimated or experimentally measured for plastic nets under arid conditions. In this study, the convected heat exchanges with different plastic nets were quantified based on an energy balance applied to the nets under outdoor natural conditions. Therefore, each net was tacked onto a wooden frame, fixed horizontally at 1.5-m height over the floor. The downward and upward solar and thermal radiation fluxes were measured below and above each net on sunny days; also the wind speed over the net, and the net and air temperatures were measured, simultaneously. Nets with different porosities, colors and texture structures were used for the study. The short and long wave’s radiative properties of the nets were pre-determined in previous studies to be used. Re and Gr numbers were determined and used to characterize the convection mechanism over each net. The results showed that forced and mixed convection are the dominant modes existing over the nets during most of the day and night times. The nature of convection over nets depends mainly on the wind speed, net-air temperature difference and texture shape of the net rather than its color and its porosity.

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