摘要
建立了灭火泡沫在水平固体表面铺展的数理模型和数值计算方法,分析了灭火泡沫在水平固体表面铺展瞬变过程以及初始边界条件和泡沫流变性对泡沫铺展过程的影响。结果表明,随着泡沫覆盖层向下游铺展,泡沫铺展前沿推进速度发生衰减,衰减幅度逐渐减小。灭火泡沫流变特性直接决定泡沫覆盖层内屈服面的垂直位置及屈服区域剪切率的大小,进而影响泡沫铺展过程。较低的泡沫屈服应力、较高的稠度系数和较大的流动行为指数有利于泡沫铺展,导致给定时间内泡沫覆盖层铺展距离增大,泡沫覆盖层厚度沿水平方向分布梯度变小,泡沫覆盖层内屈服区域增大。
The mathematical model and numerical method of firefighting foam spread over horizontal solid surface were established,and the transient process of firefighting foam spread over horizontal solid surface and the influence of initial boundary conditions and foam rheology on the foam spreading process were analyzed.The results show that,as the foam layer spreads downstream,the advancing speed of the foam front decreases,and the attenuation amplitude decreases gradually.The rheological behavior of firefighting foam directly determine the vertical position of the yield surface in the foam cover and the shear rate in the yield area,which in turn affects the foam spreading process.The lower yield stress,higher consistency coefficient,and larger flow behavior index of firefighting foam are favorable for foam spreading,resulting in an increase in the spreading distance of the foam layer in a given time,a decrease in the distribution gradient of the foam layer thickness along the horizontal direction,and an increase in the yield area within the foam layer.
作者
包有权
王璐
智会强
杜霞
Bao Youquan;Wang Lu;Zhi Huiqiang;Du Xia(Tianjin Fire Science and Technology Research Institute of MEM,Tianjin 300381,China;Key Laboratory of Fire Protection Technology for Industry and Public Building,Ministry of Emergency Management,Tianjin 300381,China;Tianjin Key Laboratory of Fire Safety Technology,Tianjin 300381,China)
出处
《消防科学与技术》
CAS
北大核心
2023年第4期526-531,共6页
Fire Science and Technology
基金
国家自然科学基金青年科学基金项目(12202376)
应急管理部天津消防研究所基科费项目(2021SJ17)。
