细水雾衰减目标热辐射的谱带-灰体模型

Spectral Bands-Grey Assumption Model for Radiative Heat Shielding with Fine Water Sprays

在火灾防护中为提高热辐射传输计算的效率,建立了多分散细水雾0.8~20μm辐射特性参数数据库,并提出了两种谱带一灰体模型。本文中,辐射特性参数采用数据库调用的方法获取,而细水雾非灰特性采用谱带一灰体模型处理。通过所建三种模型的相对误差和计算效率分析,发现灰体假设模型的相对误差较大,且随水雾光学厚度的增大而增大;而谱带一灰体模型具有很好的精度。总体讲,谱带模型具有最好的精度,但效率最差;灰体假设模型效率最高,但精度最差;只有谱带一灰体模型既兼顾了效率又兼顾了精度。

For the purpose of improving the calculation efficiency of shielding and attenuating thermal radiation in fire protection with polydisperse fine water sprays,a database of radiative properties of sprays covering the wavelength range of 0.8~20 μm and droplets radius range of 1~300 μm is constructed.Also a method of combining database calls for radiative properties acquisition and spectral bands-grey assumption model for processing the non-grey characteristics of sprays is proposed.By the contrast analysis relative errors of three models constructed,it's found that the grey assumption model has larger relative errors,and the relative error increases along with the increasing of optical depth of water sprays,however,the Spectral bands-grey assumption model has fine accuracy.In a word,the spectral bands model has the best accuracy but the worst calculation efficiency,the grey assumption model has the best efficiency but the worst accuracy,only the spectral bands-grey assumption model gives consideration to both the efficiency and accuracy.