대향류 메탄/공기 확산화염에서 복사모델이 소화한계에 미치는 영향

초록

Effect of radiation models on the suppression limits in counterflow CH4/air diffusion flame was numerically investigated with fundamental experiments for the numerical validation. N2 and CO2 were considered as extinguishing agents. The differences in extinguishing concentration between OTM and SNB radiation models which have different accuracy levels were examined. As a result, there is no considerable difference in extinguishing concentration for the N2 dilution as the radiation models with different accuracy levels were used. As the CO2 having strong radiative effect was diluted in the low strain flames, however, the radiation model with high predictive accuracy such as SNB should be used. In particular, the CO2 dilution in fuel stream leads to the significant difference in extinguishing concentration between OTM and SNB models. Therefore, it is necessary that the radiation model should be reasonably chosen with the consideration of numerical accuracy and computational time for the prediction of extinguishing concentration.