The Assessment Of FDS Simulation In Estimation Of Critical Velocity For Pool Fire Based On Model Scale In Curved Tunnel

Document Type : Scientific - Research

Authors

1 -

2 Faculty of Mining, Petroleum & Geophysics Engineering

3 Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood, Iran

Abstract

In terms of longitudinal ventilation design, airflow velocity and the reverse flow of smoke are the two most important parameters in a tunnel fire. Because critical velocity should not be more or less than the actual value, it is difficult to estimate. In fire study, computer simulation is very important. This study is focused on fires in curved tunnels using a small-scale model (in a 1/20 scale) experiments and Computational Fluid Dynamics (CFD) simulations. At first, grid sensitivity analysis and its impact on HRR estimation were investigated. The result of this is a significant effect of gridding dimensions on the correct estimation of HRR and the necessity of accuracy in its selection. Then, the effect of the pool edge was investigated. The absence of the pool edge decreased by about 30 % estimated value. In the third section, the results of HRR for two pool fire were compared and it has been found that the software is able to properly estimate HRR. After construction curved tunnel and using physical equipment, critical velocity in the tunnel was determined. The results of numerical and physical study were compared and the results show good accuracy in the critical velocity estimation. Du to critical velocity in curved tunnel (0.92 m/s) and in straight tunnel (0.82 m/s), it can be understood that if there is a curvature in the tunnel, then critical velocity is higher.

Keywords

References

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History

  • Receive Date: 18 January 2020
  • Revise Date: 09 April 2020
  • Accept Date: 12 April 2020

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