Propagation of axisymmetric ceiling jet front produced by power law time growing fires

The propagation and flow properties (temperature and velocity) of the ceiling jet front generated by a fire is essential for the prediction of detection response times and also important for the prediction of smoke filling in spaces having large floor area (for example 5000 m(2)) especially if the ceiling height is not large (for example less than 4m). This paper develops a correlation based on experimental data in time-square growing fires to relate with time the distance the ceiling jet front has traveled. The correlation is in a form that can be applied to all growing fires including power law growing fires and is validated by comparison with existing experimental data for the initial development of steady fires and with CFD simulations. Moreover, generalized temperature rise and velocity histories near the front are proposed based on existing experiments in time square growing fires. (C) 2003 Elsevier Science Ltd. All rights,reserved.