不同隧道坡度下射流风机临界风速研究

为研究隧道坡度对射流风机临界风速的影响，通过理论分析与数值模拟，采用全尺寸隧道模型和5种不同火源功率，考虑0%，±1%，±3%，±5%，±7% 9种不同隧道坡度，研究隧道坡度对射流风机临界风速的影响规律。结果表明:坡度对射流风机临界风速有较大影响。在射流风机与火源纵向间距不小于100 m情况下，即其临界风速与火源纵向间距无关；当上坡时，其临界风速与火源功率的1/3次方成正比，坡度越大，临界风速越小；当下坡时，其临界风速与火源功率的1/3次方成正比，坡度（绝对值）越大，临界风速越大；对数据结果进行拟合，得到上坡与下坡时的射流风机临界风速模型，并与模拟结果取得了较好的一致性。

Study on critical wind velocity of jet fan under different tunnel slopes

In order to study the influence of tunnel slope on the critical wind velocity of jet fan,through the theoretical analysis and numerical simulation,the full scale tunnel model and 5 different heat release rates (HRR) of fire source were adopted s,and the influence of tunnel slope on the critical wind velocity of jet fan was studied considering 9 different tunnel slopes such as 0%,±1%,±3%,±5% and ±7%.The results showed that the slope had great impact on the critical wind velocity of jet fan.The critical wind velocity of jet fan was independent with the longitudinal distance of fire source when the longitudinal distance between the jet fan and the fire source was not less than 100 m.When the slope was positive,the critical wind velocity was proportional to the 1/3 power of the HRR of fire source,and the larger the slope,the smaller the critical wind velocity.When the slope was negative,the critical wind velocity was proportional to the 1/3 power of the HRR of fire source,and the larger the slope (absolute value),the larger the critical wind velocity.The model of critical wind velocity of jet fan when the slope was positive and negative was obtained through the fitting of data results,and results were consistent with the simulation results.