Numerical Prediction of Flow and Combustion Characteristics of a Model Annular Combustor

Abstract

Two instantaneous chemistry descriptions (full chemical equilibrium and laminar flamelet) were applid to the prediction of gaseous reaction in a small-scale combustor. The chemical state relationships were combined with a single conserved scalar/β-function pdf/k-ε turbulence model closure. Encouraging results were obtained for the flowfield and conserved scalar distributions, although only when the jet entry boundary conditions were altered to accord closely with several expected experimental features. These predictions imply that any acceptable approach to combustor modelling must extend calculations to include the outer annulus. Exit temperature levels were predicted fairly well, but the quality of internal distributions deteriorated due to errors in predicted fuel/air mixing. Differences between the two chemistry models were small except for CO and H2 species concentrations where the flamelet model gave better agreement with experiments.