纵向通风隧道内车厢溢出火羽流的卷吸行为与烟气层特征参数演化研究

Under the condition of ejected fire plume from vehicle carriage in a longitudinal ventilated tunnel, due to the constraint effect of vehicle itself on the entrainment behavior of ejected fire plume, and the complex flow field caused by vehicle blocking effect, the entrainment behavior of ejected fire plume from vehicle carriage and characteristic parameters evolution of smoke layer will be significantly changed. A classic model of tunnel fire based on the free fire plume theory cannot be applied to the conditions of ejected fire plume from vehicle carriage in a longitudinal ventilated tunnel. Theoretical analysis, experimental research and numerical simulation method will be carried out to investigate the entrainment behavior of ejected fire plume from carriage and characteristic parameters evolution of smoke layer:.(1) Description model will be built to characteristic flame shape, temperature distribution, and highest ceiling temperature distribution of ejected fire plume from carriage in a longitudinal ventilated tunnel. .(2) The entrainment characteristic of ejected fire plume from carriage in a longitudinal ventilated tunnel will be discovered, and its dimensionless mathematical model of temperature profile will be proposed; .(3) Dimensionless mathematical model will be built to describe thermal smoke back-layering flow length and critical velocity of ejected fire plume from carriage in a longitudinal ventilated tunnel. .The studies of this project is an important complement to the classical theory of tunnel fires and have important scientific significance; Meanwhile, it is also important reference value for the smoke exhaust design of tunnel fire.

在纵向通风隧道内车厢内火灾溢出火羽流条件下，由于车厢自身对溢出火羽流卷吸的限制作用，再加上车厢阻塞效应形成的复杂流场，必将导致溢出火羽流的卷吸行为及其烟气层特征参数演化与分布发生明显改变，原有基于自由火羽流建立的隧道火灾经典模型不再适用。本项目拟通过理论分析、实验研究和数值模拟分析，揭示纵向通风隧道内车厢溢出火羽流的卷吸行为与烟气层特征参数演化规律：.（1）建立纵向通风隧道内车厢溢出火羽流火焰形态、溢出火羽流温度分布和顶棚最高温度分布理论表征模型；.（2）揭示纵向通风隧道内车厢溢出火羽流的烟气层卷吸特性与温度分布规律；.（3）建立纵向通风隧道内车厢溢出火羽流的烟气逆流长度与临界纵向风速模型。.研究纵向通风隧道内车厢溢出火羽流卷吸行为与烟气层特征参数演化规律，将对现有隧道火灾基础理论形成重要补充，具有重要科学意义；同时对于指导建筑隧道火灾防排烟设计，具有参考价值。

针对纵向通风隧道内车厢内火灾溢出火羽流，由于车厢自身和隧道侧壁对溢出火羽流卷吸限制作用，再加上车厢阻塞效应形成的复杂流场，必将导致隧道内车厢溢出火羽流的卷吸行为及其动力学特征参数演化与分布发生明显改变，原有基于自由火羽流建立的隧道火灾经典模型不再适用。本项目主要通过实验研究和理论分析，揭示了纵向通风隧道内车厢溢出火羽流的卷吸行为与烟气层特征参数演化规律：. （1）揭示了纵向通风隧道内车厢溢出火羽流的卷吸受限影响，建立纵向通风隧道内车厢溢出火羽流火焰尺寸的无量纲表征模型，分析了受限火羽流的温度分布特征。提出了耦合多种物理参数的隧道内车厢开口火溢流情况下隧道顶棚最高温升的无量纲模型。. （2）量化分析了隧道内不同车厢和侧壁间距影响下车厢溢出火羽流的物理卷吸差异，揭示了隧道火灾烟气层卷吸空气特征。同时建立了纵向通风隧道内车厢溢出火羽流的烟气层失稳判据。. （3）分析了纵向通风隧道中车厢溢出火羽流情况下的烟气层临界控制参数（如临界控制风速）和烟气逆流长度特征，建立了纵向通风隧道中车厢溢流火羽流情况下的烟气逆流长度、临界纵向风速与限制风速的无量纲表征模型。. 项目圆满完成了预定的研究目标和成果指标：已在国内外重要学术期刊上发表学术论文42篇SCI期刊论文，2篇EI检索论文；授权中国发明专利12项。培养硕士毕业研究生6名。项目注重学术交流合作，累计参加国内外学术会议32人次，其中线上和线下参加国际学术会议12人次。项目负责人获得首届公共安全科学技术奖（青年科技奖）、中国职业安全健康协会科学技术奖一等奖等荣誉称号，担任隧道和地下空间领域权威期刊Tunnelling and Underground Space Technology火灾安全专刊Guest Editor。