한국전산유체공학회지 (Journal of computational fluids engineering)

한국전산유체공학회 (Korean Society of Computational Fluids Engineering)
권호 표지
DOI QR코드

DOI QR Code

수직벽 화재 자연대류에 의한 난류 경계층 열유동 특성 해석

ANALYSIS OF TURBULENT BOUNDARY LAYER OF NATURAL CONVECTION CAUSED BY FIRE ALONG VERTICAL WALL

  • 장용준 (한국철도기술연구원, 시험품질분석팀) ;
  • 김진호 (한국철도기술연구원, 스마트역사연구팀) ;
  • 류지민 (한국철도기술연구원, 시험품질분석팀)
  • Jang, Yong-Jun (Railroad Safety and Certification Center, Korea Railroad Research Institute) ;
  • Kim, Jin-Ho (Smart Station Research Team, Korea Railroad Research Institute) ;
  • Ryu, Ji-Min (Railroad Safety and Certification Center, Korea Railroad Research Institute)
  • 투고 : 2016.06.22
  • 심사 : 2016.10.04
  • 발행 : 2016.12.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

The analysis of characteristics of turbulent flow and thermal boundary layer for natural convection caused by fire along vertical wall is performed. The 4m-high vertical copper plate is heated and kept at a uniform surface temperature of $60^{\circ}C$ and the surrounding fluid (air) is kept at $16.5^{\circ}C$. The flow and temperature is solved by large eddy simulation(LES) of FDS code(Ver.6), in which the viscous-sublayer flow is calculated by Werner-Wengle wall function. The whole analyzed domain is assumed as turbulent region to apply wall function even through the laminar flow is transient to the turbulent flow between $10^9$<$Gr_z$<$10^{10}$ in experiments. The various grids from $7{\times}7{\times}128$ to $18{\times}18{\times}128$ are applied to investigate the sensitivity of wall function to $x^+$ value in LES simulation. The mean velocity and temperature profiles in the turbulent boundary layer are compared with experimental data by Tsuji & Nagano and the results from other LES simulation in which the viscous-sublayer flow is directly solved with many grids. The relationship between heat transfer rate($Nu_z$) and $Gr_zPr$ is investigated and calculated heat transfer rates are compared with theoretical equation and experimental data.

키워드

참고문헌

  1. 2014, "Technical Specifications for Urban Railway Vehicles," KRTS-VE-Part51-2014(R1)
  2. 2005, Hong, W.-H., "2.18 Lesson and Record for Disastrous Accident of Daegu-Subway Fire," 119 Magazine.
  3. 2015, Kim, J.-H., "The study for validity and basic-plan of train, disaster measures, aerodynamic characteristics for GTX," KRRI-STUDY 2015-G-08-01(Korea Railroad Research Institute).
  4. 1994, Fletcher, D.-F., Kent, J.-H. and Apte, V.-B., "Numerical Simulations of Smoke Movement from a Pool Fire in a Ventilated Tunnel," Fire Safety Journal, Vol.23, pp.305-325. https://doi.org/10.1016/0379-7112(94)90033-7
  5. 2011, Wang, B., "Comparative Research on Fluent and FDS's Numerical Simulation of Smoke Spread in Subway Platform Fire," Procedia Engineering, Vol.26, pp.1065-1075. https://doi.org/10.1016/j.proeng.2011.11.2275
  6. 2010, Huang, Y.-D. and Gao, W., "A Numerical Study of The Train-Induced Unsteady Airflow in a Subway Tunnel with Natural Ventilation Ducts Using The Dynamic Layering Method," Journal of Hydrodynamics, Vol.22, No.2, pp.164-172. https://doi.org/10.1016/S1001-6058(09)60042-1
  7. 2013, McGrattan, K., McDermontt, R., Weinschnk, C. and Overholt, K. "Fire Dynamics Simulator(Version 6) User's Guide," NIST.
  8. 2004, Gao, P.-Z., Liu, S.-L., Chow, W.-K. and Fong, N.-K., "Large Eddy Simulation for Studying Tunnel Smoke Ventilation," Tunneling and Underground Space Technology, Vol.19, pp.577-586. https://doi.org/10.1016/j.tust.2004.01.005
  9. 2009, Jang, Y.-J., Lee, C.-H., Kim, H.-B. and Jung, W.-S., "The Examination of Accuracy of Fire-Driven Flow Simulation in Tunnel Equipped with Ventilation," Journal of Computational Fluids Engineering, Vol.14 No.3, pp.109-116.
  10. 2008, Park, W.-C. and Trouve, A., "Numerical Simulation of Vertical Wall Fires," Journal of Korean Institute Fire Science & Engineering, Vol.22, No.3, pp.181-187.
  11. 2015, Jang, Y.-J., Ryu, J.-M., Ko. H.-S., Park, S.-H. and Koo, D.-H., "Turbulent Flow Characteristics of Channel Flow Using Large Eddy Simulation with Wall-Function(FDS Code)," Journal of Computational Fluids Engineering, Vol.20 No.3, pp.94-103. https://doi.org/10.6112/kscfe.2015.20.3.94
  12. 1988, Tsuji, T. and Nagano, Y., "Characteristic of a turbulent natural convection boundary layer along a vertical flat plate," International Journal of Heat Mass Transfer, Vol.31 No.8, pp.1723-1734. https://doi.org/10.1016/0017-9310(88)90284-0
  13. 2003, Temmerman, L., Leschziner, M.A., Mellon, C.P. and Frohlich, J, "Investigation of wall-function approximation and subgrid-scale models in large eddy simulation of separated flow in a channel with streamwise periodic constrictions," International Journal of Heat and Fluid Flow, Vol.24, pp.157-180. https://doi.org/10.1016/S0142-727X(02)00222-9
  14. 1991, Werner, H. and Wengle, H., "Large-eddy simulation of turbulent flow over and around a cube in a plate channel," 8th Symposium on Turbulent Shear Flows, pp.155-168.
  15. 1993, Kays, W.M. and Crawford, M.E., "Convective Heat and Mass Transfer, Third edition," McGraw Hill.