基于阻滞影响的隧道临界风速研究

Study on Critical Velocity Considering the Blockage of Road Tunnel

临界风速的研究对于隧道火灾时的烟气控制、消防救援、人员逃生等有重要意义。临界风速的计算受到火源和洞内车辆阻滞的影响,为了给出考虑上述阻塞的临界风速计算公式,建立了考虑隧道火灾时火源和洞内车辆阻塞数值计算模型,分析了火源处阻塞或上游车辆阻塞单一因素对临界风速的影响;修正了考虑火源处阻塞的临界风速计算公式;提出了一个新的同时考虑火源上游阻塞以及火源断面阻塞的无量纲临界风速计算公式,并与实验结果进行对比验证其准确性。研究表明:本文公式平均误差在10%以内,临界风速随阻塞比增大而减小,火源处阻塞对临界风速的影响显著于上游车辆阻塞。

Critical velocity has a great influence on tunnel fire smoke control,fire prevention,as well as human rescue. Critical velocity is mainly influenced by the fire source blockage and the car blockage. A numerical model considering the factors of the blockage of fire source and upstream car blockage is presented to establish the critical velocity calculating formula. The influence of the single factor on the critical ventilation velocity is analyzed through the numerical results. The formula of the critical velocity with section compression of fire is corrected. A new nondimensionalized formula considering the upstream car block and fire source is proposed. The precision of the formula is confirmed by comparing the results from the calculation and the experiments. The study shows that the average error of the formula is within 10% and the critical decreases with the increase of blockage ratio. The fire source blockage has a more significant influence on critical velocity.