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针对火灾场气流与焰域温度空间耦合变化时的结构响应,通过考虑气流流速及焰围空间和结构物高度的相互作用效应,建立了焰流场环境火灾模型。采用时间增量迭代的方法计算了焰流场温度,研究了复合边界控制方程和对流换热与流速之间的相互关系。分析了流场中结构迎流面和侧流面温度分布状态,研究了混凝土空心薄壁墩的环境火灾场景,建立了焰流场结构耦合模型,揭示了焰流效应下混凝土空心薄壁墩三维空间火温时变分布规律。研究结果表明:火延时间为120min,流速为3m·s-1时,近火点温度比其他流速下温度约高100℃,流速对火源温度呈非线性影响状态;500℃以上的高温层在混凝土空心薄壁墩迎火面分布深度仅为7cm,在竖向荷载作用下空心薄壁墩外层迎火面混凝土易产生层剥现象;迎流面温度远高于侧流面温度,背火面温度无变化;稳态低流速场中流速的变化可改变不同温度区域的分布,并扩大迎火面高温区面积。
Aiming at the structural response of the coupling between the fire field and the flame temperature field, a flame model of the flame field was established by considering the interaction between the flow velocity of the flame and the height of the flame space and the height of the structure. The temperature field of the flame flow field was calculated by the method of time incremental iteration. The relationship between the complex boundary governing equation and the convection heat transfer and the flow velocity was studied. The temperature distribution of the flow field and the side flow surface in the flow field was analyzed. The scene fire scene of hollow concrete thin-walled pier was studied, the coupling model of flame field structure was established, and the three-dimensional Spatial variation of fire time and temperature. The results show that when the fire delay time is 120min and the flow rate is 3m · s-1, the near-fire point temperature is about 100 ℃ higher than other flow rates, and the flow rate has a non-linear effect on the ignition source temperature. The over 500 ℃ high- In the concrete hollow thin-walled pier fire face distribution depth of only 7cm, vertical thin-walled pier under the outer wall of the fire-resistant concrete prone to layer peel phenomenon; Ying Ying surface temperature is much higher than the lateral surface temperature, back No change in the temperature of the fire surface; steady flow velocity changes in low velocity field can change the distribution of different temperature zones, and expand the area of high temperature fire area.