室火轰燃的大涡模拟

采用一套修正的适用于低马赫数浮力流的N-S方程组来描述火灾场,运用Smagorinsky亚格子模型的大涡模拟方法对室内池火的轰燃发展过程进行了数值模拟,把模拟与实验结果进行了对比和分析。结果表明,该方法能较好地预测轰燃。同时模拟结果显示火焰区向房间后部偏转稍大,近壁处温度预测的误差大一些,随着亚格子模型的不断完善和计算能力的提高,用该技术来预测轰燃现象会更加准确。

Large eddy simulation of a compartment flashover fire

Large eddy simulation(LES) with Smagorinsky subgrid-scale model was performed to investigate the flashover fire in a three-dimensional compartment.An approximate form of the Navier-Stokes equations for the low Mach number,buoyancy driven flow,mixture fraction-based combustion model and finite volume radiation model were solved with sufficient temporal and spatial resolution.The computed temperature profiles were compared with experimental data,and a relatively good agreement was obtained.In addition,the results could give some idea of the overall flow pattern.Agreement was not as good near the ceiling,and flame deflected more from central line of the room;the results will be improved with increasing of computer power and applying of more complicated SGS model.This study provides useful information that LES technique can simulate flashover fires in a compartment.