The Assessment of heat release rate in Estimation of Critical Velocity in Curved Tunnel fire

Document Type : Research - Paper

Authors

1 Ph.D Student, Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood University of Technology, Shahrood, Iran

2 Professor, Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood University of Technology, Shahrood, Iran

Abstract

In terms of longitudinal ventilation design, critical velocity and its estimation are the two most important parameters in a tunnel fire. Critical velocity must be accurately selected to provide safe conditions in a closed environment such as tunnels. 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. Heat Release Rate (HRR) is considered as one of the key parameters in all numerical studies and physical experiments of the fire. In this study, a numerical study was carried out to evaluate the Heat Release Rate in pool fire Simulation in FDS software and small physical scale experiment. In the first step, grid sensitivity analysis and its impact on HRR estimation were investigated. The critical velocity of the physical model was equal to 0.90m/s and 0.92m/s in the numeric model. After data validation, it was concluded that increasing the HRR increases the critical velocity, so based on the results of the changes, it can be seen that this parameter is very important in estimating the critical velocity. But, this trend only dominates a certain range and the results show that outside of this range, the critical velocity is independent of the amount of HRR. On the other hand, the trend of increasing the critical velocity compared to the heat release rate for the curved tunnel, with a difference of about 10%, is in a higher position than the straight tunnel.

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References

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Journal of Mineral Resources Engineering
Volume 6, Issue 4 - Serial Number 22
December 2021
Pages 55-69

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History

  • Receive Date: 03 July 2020
  • Revise Date: 01 March 2021
  • Accept Date: 02 March 2021

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