在遵循雷诺准则的长大隧道模型试验中,保证模型与原形的压力降相等是当前的难题。为此,本文提出在出风口处安装节流口而模拟模型隧道长度延伸。在隧道通风模型上,完成了5组节流口面积比的试验,得到了平均风速、静压和节流口处风速;以此为边界条件,节流口面积比进一步扩展至9组,量化面积比对流场参数的影响,建立了面积比与节流口局部阻力的关系。结果表明:面积比在0.108~0.192时,隧道模型当量长度计算值骤增;小于0.108时,当量长度计算值随通风机频率变化而呈现发散,确定出了计算模型的面积比适用范围;最后,得到了适用于面积比不小于0.108的隧道当量长度计算式。该公式极大放宽了隧道通风模型长度,提供了重要的实验流体力学参考。
Ensuring that the pressure drop between the model and the original shape is equal is currently a challenge in long tunnel model tests that follow the Reynolds criterion. Therefore, this article proposes to install a throttling port at the air outlet to simulate the extension of the model tunnel length. On a tunnel ventilation model, complete 5 sets of experiments on the area ratio of the throttle opening to obtain the average wind speed, static pressure, and wind speed at the throttle opening; Using this as the boundary condition, the area ratio of the throttling port was further expanded to 9 groups, quantifying the influence of the area ratio on the flow field parameters, and establishing the relationship between the area ratio and the local resistance of the throttling port. The results show that when the area ratio is between 0.108 and 0.192, the calculated equivalent length of the tunnel model increases sharply; When it is less than 0.108, the calculated value of equivalent length diverges with the variation of fan frequency, determining the applicable range of area ratio of the calculation model; Finally, a formula for calculating the equivalent length of tunnels with an area ratio of no less than 0.108 was obtained. This formula greatly broadens the length of the tunnel ventilation model and provides important experimental fluid dynamics references.
[1] 洪开荣, 冯欢欢. 中国公路隧道近10年的发展趋势与思考[J]. 中国公路学报, 2020,33(12):62-76.
[2] Jing Z Z. NFPA 502: Standard for road tunnel, bridges, and other limited access highways[J]. Magazine of the SAREK, 2003, 32(2): 12-17.
[3] 高孟理. 中梁山隧道通风的模型试验研究[J]. 公路,1994(10):17-23.
[4] 蒋树屏. 公路隧道竖井送排通风模式及工程应用[J]. 世界隧道,1998(4):43-48.
[5] 刘伟, 涂耘, 易亚滨, 等. 公路隧道营运通风模型实验的相似理论研究[J]. 公路交通技术,1999(1):27-29,40.
[6] Ingason H, Li Z Y. Model scale tunnel fire tests with longitudinal ventilation[J]. Fire Safety Journal, 2010, 45(6): 371-384.
[7] 袁建平, 方正, 唐智, 等. 城市隧道火灾组合式排烟特性研究[J]. 武汉大学学报(工学版), 2010,43(6):738-742.
[8] Tanaka F, Kawabata N, Ura F. Smoke spreading characteristics during a fire in a shallow urban road tunnel with roof openings under a longitudinal external wind blowing[J]. Fire Safety Journal, 2017,90: 156-168.
[9] Seike M, Kawabata N, Hasegawa M, et al. The retarding effect of fixed barriers on smoke propagation in tunnel fires[J]. Tunnelling and Underground Space Technology Incorporating Trenchless Technology Research, 2019,85: 100-113.
[10] 董向阳, 陈世强, 唐文哲, 等. 地铁隧道排烟口无量纲结构参数与局部阻力研究[J]. 中国安全生产科学技术,2022,18(11): 148-154.
[11] 雷震霖, 陈世强, 陈永平, 等. 长大区间隧道抽出式串联通通风机排烟能力实验研究[J]. 中国安全生产科学技术,2023, 19(3):115-120.
[12] 刘敏章. 超长隧道多运动列车活塞风特性及其模型简化研究[D]. 天津:天津大学,2020.
[13] 戴国平, 田沛哲, 夏永旭. 二郎山公路隧道火灾通风对策[J]. 长安大学学报(自然科学版),2002(6):42-45.
[14] 张涛, 郭小红, 周国光. 雪峰山隧道通风竖井设计[J]. 中南公路工程,2006(1):109-112.
[15] 胡彦杰, 龙正聪. 雪峰山隧道通风系统设计[J]. 中南公路工程,2006(1):103-108.
[16] 涂耘. 雪峰山隧道运营通风模型实验研究[J]. 公路交通技术,2005(5):118-120,132.
[17] 王亚琼, 李林峰, 来凯, 等. 隧道通风阻力格栅局部阻力试验[J]. 中国公路学报, 2020,33(3):152-159.
[18] 邓敏, 闵泉, 熊雅, 等. 基于流体力学相似理论的“互补式+排烟竖井”组合通风模型试验研究[J]. 中外公路, 2021,41(1): 190-196.
[19] 袁浩庭, 陈超, 李琼, 等. 城市地下道路分(合)流匝道通风阻力特性[J]. 隧道建设(中英文), 2017,37(11):1409-1416.
