Browse > Article
http://dx.doi.org/10.14346/JKOSOS.2015.30.6.18

Effects of Initial Condition and Opening Geometry of a Compartment on the Gravity Current in the Backdraft  

Park, Ji-Woong (Department of Safety Engineering, Pukyong National University)
Oh, Chang Bo (Department of Safety Engineering, Pukyong National University)
Han, Yong Shik (Department of Energy Plant Safety, Korea Institute of Machinery and Materials)
Do, Kyu Hyung (Department of Energy Plant Safety, Korea Institute of Machinery and Materials)
Publication Information
Journal of the Korean Society of Safety / v.30, no.6, 2015 , pp. 18-25 More about this Journal
Abstract
Computational study of a gravity current prior to the backdraft was conducted using fire dynamic simulator (FDS). Various initial conditions of mixture compositions and compartment temperature as well as four opening geometries (Horizontal, Door, Vertical, and Full opening) were considered to figure out their effects on the gravity current. The density difference ratio (${\beta}$) between inside and outside of compartment, the gravity current time ($t_{grav}$) and velocity ($v_{grav}$), and non-dimensional velocity ($v^*$) were introduced to quantify the flow characteristics of the gravity current. Overall fluid structure of the gravity current at the fixed opening geometry showed similar development process for different ${\beta}$ conditions. However, $t_{grav}$ for entering air to reach the opposed wall to the opening geometry increased with ${\beta}$. Door, Vertical, and Horizontal openings where openings are attached on the ground showed similar development process of the gravity current except for Horizontal opening, which located on the middle of the opening wall. The magnitude of $v_{grav}$ at fixed ${\beta}$ was, from largest to smallest, Full > Vertical > Door > Horizontal, but it depended on both the size and location of the opening. On the other hand, $v^*$ was found to be independent to ${\beta}$, and only depended on the geometry of the opening.
Keywords
backdraft; fire dynamics simulator(FDS); gravity current; non-dimensional velocity; compartment fire;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 C. M. Fleiscmann, "Backdraft Phenomena," Ph. D. Thesis, University of California, Berkley, 1993.
2 C. M. Fleischmann and K.B. McGrattan, "Numerical and Experimental Gravity Currents Related to Backdrafts," Fire Safety Journal, Vol. 33, pp. 21-34., 1999.   DOI
3 W. G. Weng, W. C. Fan, J. Qin and L. Z. Yang, "Study on Salt Water Modeling of Gravity Currents Prior to Backdraft using Flow Visualization and Digital Particle Image Velocimetry," Experiments in Fluids, Vol. 33, pp. 398-404, 2002.   DOI
4 W. G. Weng and W. C. Fan, "Critical Condition of Backdraft in Compartment Fires: A Reduced-Scale Experimental Study," Journal of Loss Prevention in the Process Industries, Vol. 16, pp. 19-26, 2003.   DOI
5 W. G. Weng, Y. Hasemi and W. C. Fan, "Study on Effect of Opening Location on The Occurrence of Backdraft," Tenth Interflam Symposium on Fire Science & Engineering, Edinburgh Scotland, Inter-Science Communications, London, pp. 95-103, 2004.
6 W. G. Weng, W. C. Fan and Y. Hasemi, "Prediction of the Formation of Backdraft in a Compartment Based on Large Eddy Simulation," International Journal for Computer-Aided Engineering and Software, Vol. 22, pp. 376-392, 2005.   DOI
7 R. Yang, W. G. Weng, W. C. Fan and Y. S. Wang, "Subgrid Scale Laminar Flamelet Model for Partially Premixed Combustion and Its Application to Backdraft Simulation," Fire Safety Journal, Vol. 40, pp. 81-98, 2005.   DOI
8 S. A. Ferraris, J. X. Wen and S. Dembele, "Large Eddy Simulation of the Backdraft Phenomenon," Fire Safety Journal, Vol. 43, pp. 205-225, 2008.   DOI
9 S. A. Ferraris, I. Madga and J. X. Wen "Large Eddy Simulation of the Backdraft Phenomenon and its Mitigation in Compartment Fires with Different Opening Geometries," Combustion Science and Technology, Vol. 181, pp. 853-876, 2009.   DOI
10 J. -W. Park, C. B. Oh, B. I. Choi and Y. S. Han, "A Study of Numerical Reproducibility for the Backdraft Phenomena in a Compartment using the FDS," Journal of the Korean Society of Safety, Vol. 28, No. 6, pp. 6-10, 2013.   DOI
11 J. -W. Park, "Computational Study of Backdraft Dynamics in the Compartment", Pukyong National University, 2014.
12 J. -W. Park and C. B. Oh, "Investigation of Combustion Model for the Simulation of Backdraft in a Compartment", KIFSE Proceeding of Spring Annual Conference, pp. 60-61, 2013.
13 J. -W. Park, C. B. Oh, B. I. Choi and Y. S. Han, "The Effects of Radiation and Chemical Reaction Mechanism on the Development of Backdraft in a Compartment," KIFSE Proceeding of Fall Annual Conference, pp. 91-92, 2013.
14 J. -W. Park, C. B. Oh, B. I. Choi and Y. S. Han, "Computational Study of the Initial Condition and Development of Backdraft in a Compartment", 47th KOSCO Symposium, pp. 29-32, 2013.
15 J. -W. Park and C. B. Oh, "Effect of Initial Fuel Concentration on the Occurrence of the Backdraft", Spring Conference of the Korean Society of Safety, pp. 41, 2015.
16 J. -W. Park, C. B. Oh, B. I. Choi and Y. S. Han, "Computational Visualization of the Backdraft Development Process in a Compartment," Journal of Visualization, Vol. 18, pp. 25-29, 2015.   DOI
17 J. D. McBryde, "Experimental and Numerical Modelling of Gravity Currents Preceding Backdrafts", Master Dissertation, Canterbury University, Newzealand, 2008.