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为深入了解火灾过程的特点,采用大涡模拟方法对火羽流与自然对流引起的典型竖井中的流动进行了数值模拟研究。网格滤波截断的亚格子湍能远小于流场总能量,验证了大涡模拟方法的有效性。竖井内火羽流和自然对流的计算结果与文献给出的实验值总体上符合较好。在此基础上讨论了3种不同开口形式竖井内火灾及加热情况下的内部流场,发现两者在表观上具有一定相似性,但火灾状态下流场湍流更强,卷起的涡团更多,流场温度更高。此外,开口形式亦对竖井内流型产生很大影响。
In order to further understand the characteristics of the fire process, a large eddy simulation method was used to simulate the flow in a typical shaft caused by fire plume and natural convection. The subgrid turbulent energy of the truncated grid filtering is far less than the total energy of the flow field, which verifies the effectiveness of the LES method. The calculated results of fire plume and natural convection in the shaft are in good agreement with the experimental values given in the literature. On the basis of this, we discussed the internal flow field in three kinds of open shafts with fire and heating, and found that the two have apparent similarities in appearance, but the turbulent flow field is more turbulent in the fire state. More, the flow field temperature is higher. In addition, the open form also has a great impact on the flow pattern inside the shaft.