The jet fan ventilation system is one of various ventilation systems available for the purpose of carbon monoxide extraction in underground car parks. Such a system is dependent not only on the rules applied during the design, but also the architecture of the underground car park. This paper describes a numerical model used to analyse air stagnation areas, airflow and streamline patterns and the influence of partition walls on the jet fan ventilation system. Additional focus is on the validity of the choice of the jet fan ventilation system for the underground car parks with partition walls. Results show that jet fan ventilation system is not suitable for all underground car park architecture layouts.

Fire accidents in underground car parks have a significant impact on the building structure and lives of people and firefighters. Different methods are used to obtain a reliable estimation of fire and hot smoke influence on the building structure. Numerical modelling is crucial in the fire design and is a useful tool to determine smoke stratification and clear layers for safe human evacuation and firefighter access. Smoke stratification can be checked separately for any time interval in any section of an underground car park, regardless of the underground car park architecture complexity. This paper describes numerical modelling of smoke stratification and movement in an underground car park. The results show smoke movement and smoke layer thickness during the evacuation time, and how they can help reduce the harmful influence of fire on the underground car park structure.