Experimental Research on Flame Length when a Fire Source Locates nearby Walls of Corner Configuration and Parallel Configuration

实验研究了两种墙体结构的火焰高度行为，两种墙体结构分别为角部深角开缝和平行墙体结构。这两种配置被用来模拟2010年10月11日在韩国釜山发生的典型双塔配置附近发生的火灾行为。采用1.8m(H)×0.9m(W)厚0.02m的陶瓷板模型墙，并设置0.1m×0.1m(D的典型尺寸)的方形扩散沙气燃烧器(LPG)作为模型火源，给予7.5~30kW的功率，墙与燃烧器之间的间隔(S)为0~0.5m。在两板之间的深角处有0.1m宽的缝隙的转角处，火焰高度在深角附近最高，并随着分离距离的增加而减小。我们还发现，清晰的火焰偏向角落，这一现象导致了火焰高度的降低。转角结构给出了与火焰羽流或火焰流动类似的烟囱效应的对流。当燃烧器位置远离其尺寸D的3倍时，对火焰高度伸长没有明显影响。在平行构型的壁面上，扩散火焰不仅沿壁面水平扩展，而且在垂直方向上比自由边界条件下的火焰长1.5倍，并表现出翻转贴近各壁面的行为。火焰高度随分离度的增加而减小，当燃烧器与壁面的距离为其尺寸D的3倍时，对火焰高度伸长率的影响不明显。火灾安全需要建立有效的物理模型，当火源位于双子楼和/或多个楼房附近时，可以估计火焰高度。

The flame height behavior was studied experimentally with two walls configurations which have setting of a corner having a slit at the deep-corner and a paralleled-walls configuration. These two configurations were adopted to simulate the fire behavior occurred nearby typical twin towers configuration as was occurred in Pusan, Korea, 11th Oct., 2010. Model walls of ceramic boards with 1.8m(H) by 0.9m(W) with 0.02m thick of were used and a square diffusion sand gas burner (LPG) of 0.1m by 0.1m (representative size of D) was also set and used as a model fire source giving 7.5 - 30 kW with the separation (S) between walls to the burner having 0 - 0.5m. In the case of a corner with a slit (0.1m width) at deep corner between two boards, the flame height showed the highest at around the deep corner and which decreased with the increase of separation distance. We found also that the clear flame inclination toward corner and this phenomenon gave the decrease in flame height. The corner configuration gave the convective flow against the fire plume or flame flow as similar as the chimney effect. And no obvious effect on the flame height-elongation when the burner location stood aloof 3 times farther of its size D from the corner. In the case of walls with parallel configuration, the diffusion flame not only expanded horizontally with walls surface but also elongated vertically 1.5 times longer than one in free boundary condition with showing flip-flap snuggling behavior against each wall. The flame height decreased with increase of separation, and no obviouseffect on the flame height-elongation when the burner separated 3 times farther of its size D from walls. It is necessary for fire safety to establish the valid physical model which can estimate the flame height when a fire source locates nearby twin buildings and/or plural buildings.