Experimental and numerical studies of spectral radiation reabsorption on CO2 diluted flames

Xiao Qin, Zheng Chen, Yiguang Ju

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The effects of spectral radiation absorption on the flame speed at normal and elevated pressures were experimentally and numerically investigated using the CO2 diluted outward propagating CH4-O2-He flames. Experimentally, the laminar burning velocities of CH4-O 2-He-CO2 mixtures at both normal and elevated pressures (up to 5 atm) were measured by using a pressure-release type spherical bomb. The results showed that radiation absorption with CO2 addition increases the flame speed and extends the flammability limit. In addition, it was also shown that the increase of pressure augments the effect of radiation absorption. Computationally, a fitted statistical narrow-band correlated-k (FSNB-CK) model was developed and validated for accurate radiation prediction in spherical geometry. This new radiation scheme was integrated to the HLLC Riemann solver for radiation prediction in a compressible reactive flow. The comparison between experiment and computation showed a very good agreement. The results showed that the flame geometry had a significant impact on radiation absorption and that the one-dimensional planar radiation model was not valid for the computation of the flame speed of a spherical flame. It was clearly demonstrated that the effect of radiation absorption increases with the pressure and flame size. An effective Boltzmann number was extracted from numerical simulation. Furthermore, the FSNB-CK model was compared with the grey band SNB model. It was shown that the grey band SNB model over-predicts the radiation absorption. It is concluded that any quantitative prediction of flame speed and flammability limit of CO2 diluted flame requires accurate spectral dependent radiation model.

Original languageEnglish (US)
Title of host publicationCollection of Technical Papers - 44th AIAA Aerospace Sciences Meeting
Pages14119-14127
Number of pages9
StatePublished - Dec 1 2006
Event44th AIAA Aerospace Sciences Meeting 2006 - Reno, NV, United States
Duration: Jan 9 2006Jan 12 2006

Publication series

NameCollection of Technical Papers - 44th AIAA Aerospace Sciences Meeting
Volume19

Other

Other44th AIAA Aerospace Sciences Meeting 2006
CountryUnited States
CityReno, NV
Period1/9/061/12/06

All Science Journal Classification (ASJC) codes

  • Space and Planetary Science
  • Aerospace Engineering

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  • Cite this

    Qin, X., Chen, Z., & Ju, Y. (2006). Experimental and numerical studies of spectral radiation reabsorption on CO2 diluted flames. In Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting (pp. 14119-14127). (Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting; Vol. 19).