摘要
网格划分是火灾数值模拟的重要环节,对模拟结果的精度以及模拟时间有很大影响。针对火灾数值模拟中的网格划分问题,提出了一种基于大涡模拟的网格划分优化方法。根据大涡模拟的原理,给出了滤波尺度的计算方法,并根据滤波尺度和网格比系数对火场中不同区域的网格尺寸进行优化处理。将优化方法应用于高层建筑火灾的数值模拟,运用FDS软件分别针对优化前网格、优化后网格以及精细网格进行数值模拟,对不同网格划分下的温度、氧气和二氧化碳体积分数进行比对。结果表明:网格优化后,模拟结果与精细网格之间相关系数的均值为0.987,保证了模拟精度;同时,模拟运行时间降低为精细网格的16%,有效提升了火灾模拟的计算效率。
Mesh division is an important part of fire numerical simulation,which has a great influence on the accuracy of simu-lation results and simulation time.Aiming at mesh division in fire numerical simulation,a mesh optimization method based on Large Eddy Simulation(LES)is proposed.According to the principle of decomposing motion signals in LES,a calculation method of filter scale is proposed,and the grid sizes of different areas in the fire field are optimized and adjusted according to fil-ter scale and grid ratio coefficient.The optimization method is applied to a high-rise building fire simulation,and FDS soft-ware is used to carry out numerical simulations on the pre-opti-mization mesh,post-optimization mesh and fine mesh respec-tively.Temperature,oxygen and carbon dioxide volume frac-tions of different mesh division are compared.The results show that:after mesh optimization,the mean value of the correlation coefficient with the fine grid simulation results is 0.987,which ensures the simulation accuracy.At the same time,the simula-tion running time is reduced to 16%of the fine grid,which ef-fectively improves the computational efficiency of fire simula-tion.
作者
辛海林
魏峥
杨培中
Xin Hailin;Wei Zheng;Yang Peizhong(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《消防科学与技术》
CAS
北大核心
2022年第12期1692-1697,共6页
Fire Science and Technology
基金
国家自然科学基金项目“基于结构塌落的高层建筑火灾事故逆向动力学研究及应用”(11672184)
关键词
网格优化
火灾模拟
大涡模拟
高层建筑
mesh optimization
fire simulation
large eddy simulation
high-rise building
