TITLE: TRAIN FIRE IN A TUNNEL - EFFECT OF TUNNEL VENTILATION
BY: D R Glynn, FLOWSOLVE, London. Tel: +44 181 944 0940
FOR: CROSSRAIL
DETAILS :
- Fire on lower side of train causes heat and smoke which are a hazard
for passengers escaping along walkway to safety passage.
- Heat and smoke controlled by ventilation air flow along tunnel.
- Object of CFD study was to investigate effectiveness of ventilation
in ensuring safety.
- Solution domain covered part of train downstream of fire, and length
of tunnel beyond.
- Model features - 3D steady, BFC grid, buoyancy, k-epsilon model.
continued ...
The plots show the following:
- Velocity vectors in a plane just downstream of the fire.
The fire plume passes through this plane towards the top.
Having risen, flow turns out of the plane of the plot, and
along the roof of the tunnel.
- Temperature contours on the same plane (deg K).
- Temperature contours at a plane towards the end of the train.
Note the stratification. Temperatures above the walkway would
need to be lower to ensure safe escape for passengers.
- Velocity contours at a plane behind the train. Flow is faster
near to the tunnel roof. Note the "banana" shaped contours, due
to a balance between thermal stratification and wall friction
effects.
Velocity vectors in a plane just downstream of the fire.
Temperature contours on the same plane (deg K).
Temperature contours at a plane towards the end of the train.
Velocity contours at a plane behind the train.
wbs
