Validation of air ventilation in tunnels, using experiments and computational fluid dynamics

T Myrvang, H Khawaja


The study presented in this paper concerns the ventilation system inside tunnels. The ventilation system is responsible for the removal of exhaust gases produced by vehicles and for providing a clear view throughout the tunnels in routine operations and in the event of fire. The ventilation system has several stages, which are equipped with one or more fans and can be activated together or separately. The objective of this study is to find a better correlation between the air velocity and number of ventilation stages inside a tunnel. A small experimental model representing a miniature model of a tunnel was built for the study. In addition, the problem was modelled using computational fluid dynamics (CFD) in ANSYS® Fluent 18.0 for comparison and verification. The results from experiments with the miniature model and simulations from the CFD study were found to be in good agreement and in relation to a real-case scenario. The results also indicated that an increase in the active number of ventilation stages does not result in a linear increase in the air velocity inside the tunnel.

Full Text:



NPRA. Our tasks and roles (Original in Norwegian: Våre oppgaver og roller). 2018 24-07-2018]; Available from: Link.

NPRA, Handbook on Managing Tunnel V500 (Original in Norwegian: Tunnelveiledning Håndbok V500). 2016, Norwegian Public Roads Administration.

Amundsen, F.H., The 5 major tunnel fires in Norway. 2017, Norwegian Public Roads Administration.

Lotsberg, G., NO2/NOx volume ratio in three tunnels in Norway, Observations 2007-2013. 2013, Norwegian Public Roads Administration.

Buvik, H. and R. Brandt, Long and steep tunnels - controlling fire ventilation (Original in Norwegian: Lange og bratte tunneler - styring av brannventilasjon). 2016, Norwegian Public Roads Administration.

NPRA, Handbook on Managing Tunnel V520 (Original in Norwegian: Tunnelveiledning Håndbok V520). 2016, Norwegian Public Roads Administration.

Varhaugvik, O.J., Technical queries about tunnels, T. Myrvang, Editor. 2017, Norwegian Public Roads Administration: Electro Division, NPRA northern region, Norway.

Berg, S., Final documentation / FDV - Tunnel fans E6 Sørkjostunnelen (Original in Norwegian: Sluttdokumentasjon / FDV – Tunnelventilatorer E6 Sørkjostunnelen). 2017, Systemair AS.

Middha, P. and O.R. Hansen, CFD simulation study to investigate the risk from hydrogen vehicles in tunnels. International Journal of Hydrogen Energy, 2009. 34(14): p. 5875-5886. Crossref

Amouzandeh, A., M. Zeiml, and R. Lackner, Real-scale CFD simulations of fire in single- and double-track railway tunnels of arched and rectangular shape under different ventilation conditions. Engineering Structures, 2014. 77: p. 193-206. Crossref

Migoya, E., et al., Determination of the heat release rate inside operational road tunnels by comparison with CFD calculations. Tunnelling and Underground Space Technology, 2011. 26(1): p. 211-222. Crossref

Ang, C.D., et al., Simulating longitudinal ventilation flows in long tunnels: Comparison of full CFD and multi-scale modelling approaches in FDS6. Tunnelling and Underground Space Technology, 2016. 52: p. 119-126. Crossref

Chow, W.K., On smoke control for tunnels by longitudinal ventilation. Tunnelling and Underground Space Technology, 1998. 13(3): p. 271-275. Crossref

Bubbico, R., B. Mazzarotta, and N. Verdone, CFD analysis of the dispersion of toxic materials in road tunnels. Journal of Loss Prevention in the Process Industries, 2014. 28: p. 47-59. Crossref

Fluent, A., Academic Research. release 18.0.


Copyright (c) 2018 T Myrvang, H Khawaja

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.