Abstract
Numerical predictions were applied to a gas-turbine combustor model flow where dilutions jets were injected radially inwards into a swirling flow, leading to a very strong interaction between the two streams. Effects of different inlet swirl level to the interior flow field were investigated numerically and the predicted mean and turbulence results were also contrasted with measurements. The present study demonstrates that the characteristics of the combustor flow are closely linked to the representation of the interaction between the swirl field and the jets. Diffusive transport was found to be highly influential, and this also increases the importance of turbulence representation. Comparisons with experimental measurements indicated that the stress model with an anisotropy modified (-source combined with quadratic approximation of convection fluxes represents the flow field reasonably well, in contrast to the k-ε model whose diffusive nature leads to an intense vortex core near the centreline region. Reduction of strength of the centreline recirculation zone due to the elevated level of swirl momentum transport from the swirl, was also well reproduced by the stress model variant.