Numerical Study of a Fire in a Shopping Mall Café and the Associated Evacuation Processes

Nowadays people tend to spend much more time in cafés and shopping malls than they used to before. This leads to overcrowding of the places at weekends/holidays. Therefore, a study on fire in a café and the subsequent evacuation from a shopping mall is of high importance. In this paper, such study is conducted to simulate the fire scenario and evacuation procedure from a shopping mall in Astana, Kazakhstan. The study uses Large Eddy Simulation to investigate flame and smoke propagations under full and under no operation of air diffusers. The results suggest a significant change in propagation pattern of toxic gases, as well as a noticeable shift in the amount of carbon dioxide for the cases of zero relative pressure and negative pressure. This study further investigates the effects
of air diffusers on toxic gas concentrations. Furthermore, evacuation planning is considered based on the worst case scenario (rush hour) using agent-based computer simulation. The results of the evacuation simulation showed that the total time required to evacuate the first floor of the shopping mall slightly exceed 3.5 minutes which approximates the real case and gives reasonable estimate. There were several assumptions made regarding the density of occupants in any given space, maximum speed of occupants and their respective reaction time. It was observed at a particular segment of time some evacuation routes experience congestion due to large number of people evacuating and the width of the escape doors. Increase in the width of doors lead to reduction in the evacuation time. The effectiveness of such alteration should be subject of another study.