CFD Projects

Smoke Ventilation System Design
for Kongre Vadisi Tunnel, Istanbul, Turkey

Technical challenege

Selecting appropriate ventilation equipments like supply fans, exhaust fans, and tunnel ventilation fans (TVF). Designing access and ventilation shafts. The ventilation system shall meet internationally accepted guidelines as specified by NFPA, SFPE, ASHRAE or PIARC .
As per these standards, the tenable environment should have:
i) Acceptable visibility levels.
ii) Acceptable temperature levels.
iii) Acceptable concentration of toxic air.

Engineering solutions

Using software tool Fire Dynamics Simulator (FDS):
i) Make a CFD model resembling the real scenario
ii) Analyze the problem with different specifications of the ventilation equipments.
iii) Select the optimum design which satisfies the overall goal.

Contours of smoke from the burning vehicle after 1 minute time after start of fire in 'Kongre Vadisi road tunnel – Istanbul Turkey'

Contour plot of velocity magnitude at 6.5 m (at jet fan center) from ground of 'Kongre Vadisi road tunnel – Istanbul Turkey'

Result and conclusion

CFD results show that the design of the ventilation system is influenced by the following factors
i) Ventilation type (Longitudinal / Transverse)
ii) Tunnel geometry iii) Fire source location.
iv) Fire heat release rate (HRR),
v) Type of dominant burning materials
vi) Operation of the jet fans
Using these CFD results, an economical design of tunnel ventilation system was obtained with the following factors:
i) Achieved visibility levels are under acceptance criteria.
ii) No back flow of smoke near the fire source.
iii) Tunnel ventilation fans are sufficient to push the smoke from the tunnel efficiently & effectively for a given fire intensity.
iv) Improves the safety and security of humans.

Objective

The present work is to design a tunnel ventilation system for venting out smoke in case of an accidental fire in the “Kongre Vadisi Road Tunnel – Istanbul, Turkey” using Computational Fluid Dynamics(CFD) Analysis.

Business challenge

Fire safety in road & rail tunnels is very important, When a fire breaks out in a tunnel, a large amount of smoke is generated at high temperatures leading to poor visibility and difficulty in evacuation. In most cases, the victims are poisoned or starved of oxygen by the smoke. The ventilation system must ensure the quick and safe evacuation of people from the tunnel and provide a smoke free area for fire fighters to control the fire.

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3D model with locations of tunnel portals (red and green) , tunnel ventilation fans(blue arrows with red head) & HGV fire source (truck) in 'Kongre Vadisi road tunnel – Istanbul Turkey'