Numerical simulations of gaseous flames in combustion chamber applications

Abstract

Recent developments and assessments of combustion models, numerical schemes and high-power computing allow simulations to be applied to real industrial thermal oxidizers and burners. In this paper, two type concepts in a complex geometry of a burner and combustion chamber is reviewed by means of measurements data from on-site during operations compared with the numerical simulation’s analysis. The combustion models as Flamelet, Flamelet Generated Manifolds (FGM) and Hybrid BML/Flamelet are performed to assess modeling and fundamental flow aspects of combustion instabilities in a swirl concept in the context of the Reynolds-averaged Navier Stokes (RANS) equations for gaseous flames. Simulations in real thermal oxidizers illustrate the prospective of the approach but the combustion modeling and chemistry sub-grid models are limited cases in terms of validations due to the lack of available advanced set of measurements. Specific issues associated to real thermal oxidizer are presented: on-site measurements during operations, multi-perforation of heat in the combustor walls and flame instabilities. The examples are assigned as mean flow predictions (velocity, temperature and species) and transient phenomena (ignition and flame instabilities). Finally, the conceptual differences of the potential perspectives are discussed in detail from a theoretical and practical point of view.