Fire safety assessment of semi-open car parks based on validated CFD simulations

Guidelines for the safe design of semi-open car parks require a minimum amount of open facade in order to ensure an effective removal of heat and smoke during a car fire. In this study the fire safety level of semi-open car parks is assessed by the use of validated computational fluid dynamics (CFD) simulations for seven different variants. The validation of these simulations consisted of two analyses namely a comparison with measured data of a case study and secondly a comparison with the Alpert's correlations. The dimensions of the seven variants in the assessment are based on a survey of 75 semi-open car parks in the Netherlands, out of which a typical geometry could be determined. The reached fire safety of the car park variants which comply with the guideline NEN2443 are assessed using temperature and sight length criteria for safe deployment of the fire department. Results show that three out of seven studied variants did not meet these criteria, for one variant the safety level was questionable. It is therefore concluded that it is possible to design semi-open car parks which comply with the commonly used Dutch guideline, yet when assessed with criteria for safe deployment of the fire brigade have an insufficient fire safety level.