Numerical Study of the Characteristics of the Ejected Flame Depending on the Opening Shape in Compartment Fires

In this study, numerical analysis using FDS was conducted to analyze the effect of the opening configuration of the compartment on the formation of the ejected flame and thermal radiation characteristics outside the compartment. After validating the analysis by comparisons with previous experimental results for the 2/5 scaled ISO 9705 standard compartment, numerical calculations were performed by altering the aspect ratio of the opening and the position from the bottom surface. At a fire heat release rate of 341 kW, the flame ejected from the standard-sized opening generated a heat flux that exceeded the critical value of general combustibles on a wall 1 m away. When the width of the opening was reduced to 1/4, the flow of the ejected flame bent toward the upper wall, generating a maximum heat flux that was more than three times higher than that of the standard opening.