- Author
- Watanabe, Y. | Miyazaki, S. | Sekizawa, A. | Yamada, T. | Yanai, E. | Saito, N.
- Title
- Experimental Study on Thermal Environment of a Relatively Large Fire in a Reduced Scale Model of a Horizontal Tunnel Under Ventilation Condition: Relation Between Ceiling Temperature and Ventilation Air Velocity.
- Journal
- Report of Fire Research Institute of Japan, No. 78, 22-32, September 1994
- Keywords
- tunnels | scale models | ventilation | temperature | air velocity | experiments | ceilings
- Abstract
- [ABSTRACT IN ENGLISH] Through large fire experiments using a n-heptane fire source in a reduced scale model which was 21.6 m long and 0.3 m x 0.3 m for an inside dimension, we investigated relations between the ceiling temperature and the ventilation air velocity. As the results the following were found. (1) The position of the ceiling, where the highest temperature was observed, moved from fire sources to the leeward area as the heat release rate and the ventilation air velocity were larger. When the ventilation air velocity was 0.43 m/s and the heat heat release rate was 97 kW, the ceiling temperature reached 1200 deg C and a red heat wall was observed in the leeward area in the range of 12 times of a ceiling height. (2) The ceiling temperature decreased exponentially as the ventilation air velocity increased. The decrease rate of the ceiling temperature by the ventilation air velocity was larger as the heat release rate was smaller. (3) When the ventilation air velocity was small, the ceiling temperature increased in proportion to two thirds power of Q[Q2/3] like fires with no ventilation wind. But as the ventilation air velocity became larger, the ceiling temperature did not increase in proportion to Q2/3.