Questioning the Linear Relationship Between Doorway Width and Achievable Flow Rate.
Questioning the Linear Relationship Between Doorway
Width and Achievable Flow Rate.
Gwynne, S. M. V.; Kuligowski, E. D.; Kratchman, J.;
Milke, J. A.
Fire Safety Journal, Vol. 44, No. 1, 80-87, January
doors; doorways; egress; flow rate; simulation; fire
protection engineering; data analysis; people movement;
computation; evacuation time; evacuation; codes;
regulations; impact; design applications
This paper challenges the currently assumed linear
relationship between doorway width and achievable flow.
The current view is seen as a simplification that may
lead to an overly optimistic view of the achievable flow
rates. Analyzed data are presented in order to
demonstrate the impact that the actual use of the
doorway and its design can have upon the flow rate
generated. These data are then supported by the use of
numerical simulations to demonstrate the impact that
this overestimation can have upon the design process. It
is contended that the specific flow rate assumed for a
doorway should take into consideration not only its
width, but also the design of the doorway (i.e., the
opening and closing mechanism) and how evacuees behave
in response to it. The issues raised have implications
for the governing codes/regulations, engineering
guidance and on the development of future computational