On the Analysis of Flame Pulsation and Fire Induced Vent Flow Oscillatory Behaviors in Confined Enclosures with Horizontal Openings

摘要

This paper undertakes a comprehensive analysis of flame pulsation behavior and vent flow oscillatory behavior in a confined enclosure. Experiments are carried out in a small scale confined compartment with a horizontal opening, and several configurations characterized by different pool diameters and ceiling vent sizes are considered. Flame pulsation and horizontal vent flow oscillatory behaviors are investigated during the experiments, and visualization recordings were collected. Results indicate that the flame pulsation frequency can be obtained by way of the Fast Fourier Transform (FFT) method (with recorded RGB images being transformed into pseudo-gray images based on Ostu's method) and the vent flow oscillatory frequency can also be obtained using a similar processing method. The frequencies are found to vary in accordance with variation of the horizontal opening size. Through theoretical analysis, the relationship between the flame pulsation frequency and vent flow oscillatory frequency is investigated. Moreover, it is expected that the comprehensive frequency term would alter in alignment with the parameters of the horizontal opening, and this sufficiently fitted with the experimental data.