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.

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.

Numerical Analysis of Evacuation from Taiwan Hsuehshan Tunnel Fire

2014 ◽  
Vol 955-959 ◽  
pp. 1840-1849
Author(s):  
Cherng Shing Lin ◽  
Kuo Da Chou
Keyword(s):  
Numerical Simulation ◽  
Fire Protection ◽  
Quantitative Data ◽  
Relevant Information ◽  
Simulation Software ◽  
Escape Time ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Tunnel Fire ◽  
Protection Engineering

Taiwan is an island nation with numerous mountains and few plains. Consequently, the number of tunnel projects has gradually increased and tunnels are becoming longer. Because the number of large tunnels that exceed 1000 meters in length has increased, the effective escape and evacuation of people during a fire and the minimization of injury are crucial to fire protection engineers. For this study, an actual example of a fire that occurred in Hsuehshan Tunnel (12.9 kilometers and the longest tunnel in Southeast Asia) was used. A fire dynamics simulator (FDS) including numerical simulation software was applied to analyze this fire and the relevant information that was collected was compared and verified. The fire site simulation showed the escape and evacuation of people during the fire. Simulations of the original fire site and the possible escape time for people with various attributes were discussed to provide quantitative data and recommendations based on the analysis results, which can serve as a reference for fire protection engineering.

Assessment of the Fire Dynamics Simulator for Modeling Fire Suppression in Engine Rooms of Ships with Low-Pressure Water Mist

2019 ◽  
Vol 56 (3) ◽  
pp. 1315-1352 ◽  
Author(s):  
Roberto Bellas ◽  
Miguel A. Gómez ◽  
Arturo González-Gil ◽  
Jacobo Porteiro ◽  
José L. Míguez
Keyword(s):  
Fire Suppression ◽  
Low Pressure ◽  
Water Mist ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Pressure Water

Assessment of Numerical Simulation Capabilities of the Fire Dynamics Simulator (FDS 6) for Planar Air Curtain Flows

2018 ◽  
Vol 54 (3) ◽  
pp. 583-612 ◽  
Author(s):  
Long-Xing Yu ◽  
Tarek Beji ◽  
Georgios Maragkos ◽  
Fang Liu ◽  
Miao-Cheng Weng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fire Dynamics ◽  
Air Curtain ◽  
Fire Dynamics Simulator

Spray Characterization of Aerosol Delivery Systems for Use in Stored Product Facilities

2020 ◽  
Vol 63 (6) ◽  
pp. 1925-1937
Author(s):  
Fei Xyza B. Asuncion ◽  
Daniel L. Brabec ◽  
Mark E. Casada ◽  
Ronaldo G. Maghirang ◽  
Frank H. Arthur ◽  
...  
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Droplet Size Distribution ◽  
Delivery Systems ◽  
Spray Angle ◽  
Insect Control ◽  
List Type ◽  
Aerosol Delivery ◽  
Spray Characteristics ◽  
Compressed Gas

HighlightsHandheld sprayers generated larger droplets and wider droplet size distributions than compressed gas sprayers.Sprayers with higher pressure and nozzles with wider spray angle produced smaller droplets.Droplet size distribution influenced spray coverage, mass concentration, deposition, and sprayer efficacy.The handheld sprayers had less spray coverage and efficiency than the compressed gas sprayers.The deposition at different locations was influenced by the volume of the space, aerosol dosage, and spray time.Abstract. Aerosol insecticides, including pyrethrins, can be used as methyl bromide replacements to control stored product insects inside flour mills and rice mills. The effectiveness of aerosol application for insect control requires knowing the spray characteristics of the equipment to be used and understanding factors that influence the effectiveness of insecticide application. The objectives of this study, as part of efforts to optimize aerosol applications, were to evaluate the characteristics of six aerosol delivery systems (two handheld sprayers and compressed gas sprayer systems fitted with two types of manifolds and two types of nozzles), estimate the dispersion and deposition of aerosol in a simulated stored product facility, and determine how the dispersion and deposition are affected by the characteristics of the sprayers. Results showed that the spray systems differed significantly in spray characteristics. The compressed gas sprayers generated significantly smaller droplets, more uniform droplet size distribution, and better spray coverage than the handheld sprayers. The ellipsoidal nozzle produced significantly smaller droplets than the circular nozzle. While the type of manifold had no significant effect on deposition, higher aerosol dosage and spray time resulted in significantly higher deposition. Results of this study will be used to improve spray techniques for stored product insect control, to validate computational fluid dynamics modeling of aerosol application, and to improve testing methods in large-scale spray testing inside commercial facilities. Keywords: APS spectrometer, Droplet size distribution, HELOS KR-Vario, Mass deposition, Spray characteristics, Spray nozzles.

Full-Scale Experimental and Numerical Simulation of Fire in a High-Rise Residential Building

2012 ◽  
Vol 594-597 ◽  
pp. 2251-2256
Author(s):  
Jun Tao Yang ◽  
Yun Yang ◽  
Jing Liang
Keyword(s):  
Numerical Simulation ◽  
Residential Building ◽  
Full Scale ◽  
Fire Dynamics ◽  
High Rise ◽  
Fire Dynamics Simulator ◽  
Smoke Spread

Fires in high-rise residential building were studied experimentally by using an actual building with similar inner structure. The temperatures in the building interior corridors, elevators and staircases exit were measured. At the same time the fires in this construction were simulated by using FDS (Fire Dynamics Simulator) software, the variance trends of the temperatures in different positions within high-rise residential building were studied and compared with the experiment results, and the results of this simulation are proved to be valid. The results can be used to support the study of effectively controlling of the smoke spread and evacuation in high-rise residential building.

scholarly journals The Two-Phase Conical Swirl Atomizers: Spray Characteristics

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3416 ◽  
Author(s):  
Marek Ochowiak ◽  
Andżelika Krupińska ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
Małgorzata Markowska ◽  
...  
Keyword(s):  
Flow Rate ◽  
Discharge Coefficient ◽  
Experimental Studies ◽  
Central Area ◽  
Spray Angle ◽  
Sauter Mean Diameter ◽  
Spray Characteristics ◽  
Two Phase ◽  
Mean Diameter ◽  
The Impact

This paper presents the results of experimental studies on two-phase conical swirl atomizers. The impact of various atomizer geometries and different operational parameters of the atomization process on the spray characteristics was investigated. The influence of the mixing chamber height HS to diameter DS ratio and the volumetric flow rates of liquid and gas on the discharge coefficient values, spray angle, droplet size expressed by Sauter mean diameter D32, volumetric and radial distributions of droplet diameters in the spray stream were determined. The analysis of results showed that the discharge coefficient values depend on the Reynolds number for liquid and gas and the atomizer geometry. The spray angle increases as the flow rate of liquid and gas increases depending on the applied atomizer construction. The Sauter mean diameter value is correlated with the geometric dimensions of the atomizer swirl chamber. The rapid increase in D32 occurs after exceeding the value HS/DS ≈ 3. The Sauter mean diameter also depends on the operating parameters. A central area of stream is filled with smaller sized droplets as the gas flow rate increases.

Study on Fire Prevention Performance-Based Design of a Large Underground Banquet Hall

2011 ◽  
Vol 94-96 ◽  
pp. 2065-2069 ◽  
Author(s):  
Yan Qing Bao
Keyword(s):  
Numerical Simulation ◽  
Fire Spread ◽  
Performance Based Design ◽  
Fire Prevention ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Large Fires ◽  
Simulation Results ◽  
Evacuation Safety ◽  
Set Up

There is large fires risk and difficult evacuation in underground buildings, so it is necessary to study the development of fire and evacuation procedure in underground building. In this paper, a large underground banquet hall was chosen as an example, evacuation safety in the hall was analyzed by numerical simulation. First of all, fire model and two fire scenes were set up by using the software Fire Dynamics Simulator. Then the process of fire spread was reappeared by numerical simulation, and evacuation process was simulated by using the software PathFinderTM. By comparison with both result, it was proved that there is safe personnel evacuation in the case of effective fire-fighting facilities. According to the simulation results, reasonable recommendations about fire safety of the large banquet hall was proposed. The research will contribute to fire prevention and architecture design.

Sign in / Sign up

Export Citation Format

Share Document