室内火灾烟气流动的三维大涡数值模拟

室内火灾具有较高的危险性,是建筑火灾造成人员伤亡和财产重大损失的灾害之首。利用计算流体动力学(CFD)的方法,建立了室内火灾时期烟气流动的三维大涡数值模型,目的是通过对火灾烟气流动的数值模拟,为多室火灾的控制和人员救助提供理论基础。模拟结果认为,火灾及附近地区温度较高,烟流浓度较大,高温引燃其他易燃物品的可能性加大。通风与火灾的发展状态存在密切关系,通风既能降低室内温度,加快烟流及有毒有害气体的扩散速度,同时也为火灾的进一步发展提供条件。从模拟结果与实验验证可得出结论:火源功率大小及房屋的几何尺寸影响着火灾程度、温度及烟流浓度的分布和变化,数值计算的结果总体上与实测结果存在较好的一致性。

Three-dimensional Large Eddy Simulation of Smoke Flow during Indoor Fire

Indoor fires are quite dangerous,claiming many casualties and resulting in great property loss.Using Computational Fluid Dynamics(CFD),a three-dimensional large eddy simulation model of smoke flow is set up.Through the simulation of smoke flow,the theoretical basis is provided for controlling a fire in multiple rooms,thereby saving people.The results of simulation show that high temperatures and thick smoke exist near the fire,and the probability of combusting other tinder will increase.Moreover,there are close relationships between fire and ventilation.The latter can lower the average temperature and speed up the spread of smoke flow and toxic gases,providing conditions for the further development of indoor fire.Moreover,from both the simulated calculation and physical measurement,it is shown that indoor fires and their temperature distribution and smoke concentration are influenced by the fire power and the room size.The results from calculation and measurement are quite consistent.