单跑楼梯井内火灾过程的数值模拟

针对单跑楼梯井内的火灾过程，采用大涡模拟方法，通过改变单跑楼梯井顶层门的面积，探讨了门面积的改变对楼梯井内火灾过程中空气卷吸量、排烟量、楼梯井内平均氧气浓度以及楼梯井内外压差的影响，分析了火灾烟气流动的动力学特征。研究结果表明，随着单跑楼梯井门开口面积的增加，空气卷吸量和排烟量均增加，井内平均氧气浓度增加而井内外压差逐渐降低。计算结果显示，在火灾场景中，当单跑楼梯井顶层门面积较小时，以上物理量对门高度的变化更为敏感。

Numerical simulation of the fire in a single-run stairwell

Using LES method, this paper aims to investigate the impact that the changes in the top gate area of single-run stairwell have on the volumes of entrained air and exhaust smoke, the average oxygen concentration in the stairwell and pressure difference between inside and outside of the stairwell in the fire process, and analyze the characteristics of smoke flow in stairwell fire in accordance with the fire process in the single-run stairwell. The study findings indicate that with the top gate area of single-run stairwell increasing, the volumes of entrained air and exhaust smoke volumes and the average oxygen concentration in the stairwell increase respectively while the pressure difference between the outside and inside of the stairwell gradually decreases. The calculation results show that in a fire scene the above physical quantities are more sensitive to the changes of the gate height.