scholarly journals Experimental and Numerical Study of the Discharge Performance of Particle-Laden Turbulent Flow

2022 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Hongbo Shi ◽  
Xikun Wang ◽  
Qingjiang Xiang ◽  
Gonghe Zhang ◽  
Lin Xue

In the marine fire suppression system, continuous delivery of dry chemical powder to the fire source with long powder discharge range and high dispersion concentration is essential. The work is devoted to experimental and numerical studies of the flow characteristics of the dry chemical powder jet from a horizontal injector with a wide range of Stokes numbers between 6 to 30 and Reynolds numbers between 4792 to 23,960 by considering the effect of gravitational acceleration. A CFD-based Eulerian–Eulerian multiphase model combined with Standard k-ω turbulence model was used to predict flow characteristics of particle-laden jet using dimensionless numbers, including the solid volume fraction, the normalized velocity magnitude, and the turbulent viscosity ratio. Experimental studies have been carried out for three different inflow velocities (2.06, 2.45, and 2.81 m/s). The results indicate that the particle density plays a significant role in the dispersion of the particles in the radial and axial directions. The transition from U-shaped to V-shaped solid dispersion structure on the ground can be captured with the increase of particle density. Moreover, the higher level turbulence intensity enhances the solid dispersion concentration. Finally, it was found that the Portland cement powder exhibits better discharge performance in terms of solid discharge range and dispersion concentration in comparison with other dry powders. These results have implications in the design of powder-based fire suppression system. Further studies should aim to the in-depth research on the fire extinguishing mechanism of the Portland cement powder, especially the fire suppression effectiveness and thermal decomposition process.

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Wira Setiawan ◽  
Distyan Kotanjungan

Based on statistical data in recent years, there are still quite a number of ship accidents due to fires, including on passenger ships. The water mist system is a fire suppression system that allows it to be used in the engine room with the advantage that it can keep the heat production rate low during the extinguishing process and can be operated earlier than the CO2 system. The research is conducted by using fire dynamic simulator in the engine room of a 300 GT ferry ro-ro passenger to compare the heat release rate of fire without an extinguishing system, an existing CO2 system, and a water mist system. The result shows that the CO2 fire suppression system reduces the heat release rate more rapidly to the decay phase at 375 seconds while the water mist takes more than 900 seconds. However, the fully developed phase of the water mist suppression system occurs more quickly than CO2 because the sprinklers are activated shortly after a fire occurs. Unlike water mist, the CO2 system is activated at 60 seconds so that the pre-combustion, growth, flashover, and fully developed phases are at the same HRR and time as the natural one.


2015 ◽  
Vol 22 (6) ◽  
pp. 10-18 ◽  
Author(s):  
David A. Miller ◽  
Lyric M. Rossati ◽  
Nathan K. Fritz ◽  
Michael E. Cournoyer ◽  
Howard N. Granzow

2004 ◽  
Vol 2004 (0) ◽  
pp. 307 ◽  
Author(s):  
Futoshi Tanaka ◽  
Yoshifumi Ohmiya ◽  
Shinichi Sugawara ◽  
Masahiro Morita ◽  
ken Matsuyama ◽  
...  

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Danardono A. Sumarsono ◽  
Yulianto S. Nugroho ◽  
Mariance , ◽  
I Gede Wahyu W. Ariasa

Sign in / Sign up

Export Citation Format

Share Document