DOI: 10.1615/ICHMT.2013.IntSympRadTransf
ISBN Print: 978-1-56700-280-5
ISSN Online: 2642-5629
ISSN Flash Drive: 2642-5661
RELATIONSHIP BETWEEN THE SPECTRAL LINE BASED WEIGHTED-SUM-OF-GRAY-GASES MODEL AND THE FULL SPECTRUM K-DISTRIBUTION MODEL
RESUMO
The relationship between the spectral line based weighted-sum-of-gray-gases (SLW) model and the full-spectrum k-distribution (FSK) model in isothermal and homogeneous media is investigated in this paper. The SLW transfer equation can be derived from the FSK transfer equation expressed in the k-distribution function without approximation. It confirms that the SLW model is equivalent to the FSK model in the k-distribution form. The numerical implementation of the SLW relies on a discretization of the absorption cross section where as the FSK model finds the spectrally integrated intensity by integration over the smoothly-varying cumulative-k distribution function using a Gaussian quadrature scheme. The latter is therefore in general more efficient as fewer gray gases are required to achieve a prescribed accuracy. Sample numerical calculations were conducted to demonstrate the different efficiency of these two methods. The FSK model is more efficient than the SLW model in radiation transfer in H2O; however, the two models perform similarly in CO2.