Understanding large fires in urban high-rise buildings

(27-04-2022) In his doctorate, Xiepeng Sun investigated the mechanisms behind fires with spreading flames in high-rise buildings. So that in the future, safety measures can be taken and fires in high-rise buildings are less likely to spread.

Due to the rapid development of urbanization, high-rise buildings in cities have increased significantly. As a result, fire incidents in high-rise buildings are also more frequent. Openings (e.g., open windows) between the rooms in a flat and the facade of a building can, in the event of a fire, lead to large-scale and disastrous fire spread via the facade. Therefore, the fire safety of the facade has become a major challenge.

"In my doctorate, I mainly investigated the evolution of fires in a compartment (e.g., a room) and the behaviour of the associated flame spread on the facade under different ventilation conditions. I conducted five experiments at different scales," says Xiepeng.

"Specifically, I developed a similarity analysis - based on the classical theoretical models - for the fire dynamics in the compartment, the length scale of the opening and the characteristic parameters of the ejected flame. I performed numerical simulations to visualize and analyze the structure of the flow field using the Fire Dynamics Simulator software," explains Xiepeng.

Furthermore, the mechanisms influencing the development of the fire in the compartment and the associated outbreak of the fire on the facade were revealed: the height of the fire in relation to the floor in the compartment; the shape of the opening (window in a compartment with limited ventilation); external environmental wind (sideways, from behind over the roof), giving rise to different ventilation conditions.

"Thanks to my research, safety measures can be taken so that fires in high-rise buildings are less likely to spread in the future," concludes Xiepeng.

Read a more detailed summary or the entire PhD


PhD Title: Experimental and Theoretical Study on the Ejected Facade Flame Behavior from Compartment Fires under Different Ventilation Conditions


Contact: Xiepeng Sun, Bart Merci 

Xiepeng Sun has been awarded the state-sponsored PhD Joint Training Program, and studied at  Gent University from 10.2019 to 10.2020. He has been awarded the National Scholarship for Graduate Students of the University of Science and Technology of China, First-class Award of the Science and Technology Award of China Occupational Safety and Health Association, and Outstanding doctor graduate of University of Science and Technology of China during the Ph. D period. He has received funding supported by the “The fellowship of China National Postdoctoral Program for Innovative Talents (China). He has accumulated rich experience through participating in the key project of National Natural Science Foundation of China, Excellent Youth Science Foundation of the National Natural Science Foundation of China, and so on.

During his doctoral studies, Xiepeng Sun focuses on the enclosure fire dynamics and the ejected facade flame behaviour from compartment fires, mainly including three key scientific problems of compartment-facade fire: (1) combustion behaviour inside the compartment, (2) flame ejection behaviour as well as (3) the evolution and profile of the facade flame characteristic parameter.The influence mechanism on the fire development inside the compartment and the associated ejected facade flame behaviour has been demonstrated by: the fire source elevation (above the floor) inside the compartment; the opening characteristics (casement window, reduced ventilation compartment); and external environment wind (external sideward wind and back-roof wind), forming various ventilation conditions.

He has now published 9 international peer-reviewed journal papers as the first author on Combustion and Flame, Proceedings of the Combustion Institute, Fuel, Journal of Hazardous Materials, International Journal of Thermal Sciences. He has participated in writing “Fundamental theory and mechanism of compartment-facade fire”, which is the first academic book on the topic of the ejected facade flame in China. He has been invited to make two oral presentations at 37th and 38th International Symposium on Combustion, respectively, while having acquired the Combustion Institute Travel Grant.


Editor: Jeroen Ongenae - Final editing: Ilse Vercruysse - Illustrator: Roger Van Hecke