ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
ASSESSMENT OF A HYBRID SOLUTION APPROACH FOR THE SOLUTION OF THE RADIATIVE TRANSFER EQUATION IN COMBUSTION GASES
The Finite Angle Method (FAM) yields accurate solutions of the radiative transfer equation (RTE) when used with sufficient angular resolution, especially when the medium is optically thin. However, this can be computationally expensive. On the other hand, the Spherical Harmonic Method (PN approximation) with its lowest order approximation (P1) yields a single elliptic partial differential equation and is efficient to solve. It is accurate only when the intensity field is more or less isotropic, as in optically thick media. In this study, we attempt to solve the non-gray RTE with a Hybrid approach that utilizes the efficiency of the P1 method in optically thick spectral bands while maintaining its accuracy with FAM in the optically thin bands with a cut-off and filter approach for switching between the two. Using the statistical narrow band (SNB) properties for CO2 and H2O, homogeneous and inhomogeneous mixtures enclosed in a 1D slab and a 2D square cavity are used as test cases to evaluate the Hybrid solver and its benefits. Overall, the Hybrid solver was found to be a good compromise between accuracy and efficiency. Implementation of this Hybrid approach for general multidimensional problems appears viable based on this preliminary study.