Smoke simulation in an underground train station using computational fluid dynamic

Abstract

The design of the ventilation and fire safety systems for the Johor Bahru Sentral, a semi underground train station, part of the Integrated Custom, Immigration and Quarantine Complex (ICIQ) is based on normal Malaysian Standards (MS), British Standards and the local fire department's requirements. However, the large and complex space in the underground station coupled with scheduled diesel-powered locomotives which frequent the station by stopping or passing require detailed simulations. Both ventilation and the fire safety systems employ Computational Fluid Dynamic (CFD) methods to provide realistic balance against the typical calculations based on spread sheets and certain design software. This study compares smoke simulations results performed by the mechanical and fire consultants with the simulations carried out through this project. An assumption of a locomotive catches fire near the main platform is made. The burning locomotive is the source of the smoke while the occupants on platforms and waiting areas are the subjects to escape safely. The process of the simulation includes modelling and meshing processes on the structure of "the railway station imported from Inventor CAD Autodesk software drawing. The CFD simulations are performed using Star-CCM+. The smokes flow around the building with buoyancy forces and extracted via exhaust fans. Through these simulations, we found that when a locomotive catches fire, the passengers could evacuate the building safely before the fire department machinery arrives. Furthermore, we notice that the ventilation fans activation based on detection of hazardous gases may not be efficient way to remove the latter. A schedule clean-up sync with train arrivals effectively removes toxic gas.