辐射特性模型对机舱火灾模拟的影响

分别用灰体和窄带两种不同的介质辐射特性模型,模拟了封闭机舱内火灾的发生过程,并对其中的温度、气体浓度、辐射热流等的分布进行了比较和分析。结果表明在火灾发生的前50 s之内,两种模型差别不大。在50 s之后,由于机舱内的烟气产量和CO2,H2O等多原子气体的迅速增加,两种模型的模拟结果差别增大。灰体模型对辐射换热量的预测大于窄带模型。由于辐射参与介质本身是非灰的,所以窄带模型对辐射的预测更准确。这一结论也通过气体成份分布和烟气浓度分布的结果得到了证实。研究可为机舱火灾的准确模拟研究提供参考。

Radiation Characteristics Models Impact on Engine Room Fire Simulation

Abstract: Gray and narrow-band models are used to simulate the occurrence of the fire process within a closed cabin respectively. The temperature distribution, gas concentration, radiation heat flux are calculated, compared and analyzed. Results show that within 50s of the fire process, the two models have few differences. But after 50s, due to the rapid increase of the smoke production and CO2, H2O and other polyatomic gases inside the cabin, there are more differences between the two models. Radiation heat transfer and temperature distribution calculated from gray-body model are greater than the narrow-band model. Because radiation participating media itself is non-gray, narrow-band model is more accurate. This conclusion is also confirmed by the results of gas composition distribution and smoke concentration distribution. The discuss and results of this paper can provide a reference for the simulation study of the cabin fire.