Fire Safety Science Digital Archive

Particle image velocimetry (PIV) was applied to measure detailed flow structures both at the gas and liquid phases created by a pulsating flame spread over 1-propanol, placed in a narrow wide long tray. The PIV measurements revealed small flow circulations in both gas and liquid phases just ahead of the spreading flame. Similar measurements were done earlier by Laser Sheet Particle Tracking (LSPT) technique, but LSPT data were rather qualitative and limited numbers of particles were tracked due to its manual count system. The current PIV can compensate these shortcomings with its automated particle tracking and data processing system. With PIV systems that were focused on two critical steps, just before and after flame jumping, we obtained more detailed 2-D flow fields than the LSPT and successfully obtained quantified flow vector fields. As a result, this study confirmed the earlier LSPT result that the existence of two opposite vortices in both liquid and gas phases just before the flame jumping. In the stage just after the flame jumping, however, PIV found a small circulation in the liquid phase and a weak circulation in the gas phase, both of which were not reported in our earlier study.