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COBEM 2021
26th International Congress of Mechanical Engineering
EVALUATION OF SPECTRAL MODELS FOR DIFFERENT LEVELS OF TURBULENCE INTENSITY IN A THREE-DIMENSIONAL DOMAIN
Submission Author:
Bruno de Luca Zimmer Gomes , RS
Co-Authors:
Bruno de Luca Zimmer Gomes, Guilherme Crivelli Fraga, Francis França
Presenter: Bruno de Luca Zimmer Gomes
doi://10.26678/ABCM.COBEM2021.COB2021-0423
Abstract
Turbulence-radiation interaction (TRI) is a complex phenomenon, where turbulent fluctuations affect the mean radiation field due to the highly non-linear nature of radiation, leading to what can be large errors in the predicted mean radiative quantities. The objective of the present paper is to study the effect of turbulent fluctuations on the accuracy of spectral models. The accuracy of the weighted-sum-of-gray-gases (WSGG) model are evaluated by comparison with a benchmark provided by line-by-line (LBL) integration. Turbulence is introduced in the analyses through a semi-empirical correction to the mean emission, while absorption-TRI is altogether neglected. The test cases consist of three-dimensional, non-coupled calculations, based on predefined temperature and species concentrations representative of realistic combustion scenarios for different levels of turbulence intensity. The participating medium is composed of typical combustion products, carbon dioxide and water vapor (the effect of soot is neglected). The results show that the presence of turbulent fluctuations substantially increases the radiative source term and the radiative heat flux. The average errors associated with the WSGG model are approximately 6 % and 2 % respectively. The present study contributes to the investigation of turbulence effects in reactive flows for a three-dimensional domain.
Keywords
Turbulence-radiation interaction, thermal radiation, Spectral models, temperature fluctuations, turbulent intensity
