Theoretical and Experimental Study of Critical Velocity for Smoke Control in a Tunnel Cross-Passage

• Theoretical analyses and model-scale experiments have been conducted to investigate the critical velocity in a tunnel cross-passage which is defined as the minimum ventilation velocity through the fireproof door to prevent smoke from flowing into a cross-passage. The effect of the fireproof door geometry, heat release rate, ventilation velocity and fire source location were taken into account. The critical velocity in a tunnel cross-passage varies approximately as three-second power of the fireproof door height, as one-third power of the heat release rate and as exponential law of the ventilation velocity, almost independent of the fireproof door width. The critical Froude Number range varies mainly between 5 to 10 and consequently as it is not a constant value it is not very suitable to predict the critical velocity in a tunnel cross-passage. A dimensionless correlation that can correlate well with the experimental data was proposed

Keyword

tunnel fire; cross-passage; smoke control; critical velocity

TECHNOLOGY

TEKNIKVETENSKAP

Energy- and Environmental Engineering

energi- och miljöteknik

Publication and Content Type

ref (subject category)

art (subject category)