Abstract
This paper presents measurements of 10 kHz acetone planar laser induced fluorescence (PLIF) to study the behavior of effusion cooling fluid injected into a non-reacting gas turbine combustor flow at elevated pressure. This study was performed as part of a larger effort to understand potential interactions of the swirling flame with the cooling air. The combustor — which was representative of a rich-burn/quick-quench/lean-burn (RQL) configuration — consisted of a swirl nozzle, quench jets, and a modular liner that could be fitted with various effusion cooling panels and optical access windows. Primary air was seeded with acetone, and passed through the swirl nozzle. Unseeded secondary air was passed on the outside of the liner, entering the combustion chamber through the quench jets and effusion panels. The PLIF laser sheet was arranged parallel to the effusion panel at various offset distances to visualize the mixing between the core flow and effusion jets. The PLIF images were analyzed with a POD-based methodology to de-noise the images and identify patterns in the effusion jet characteristics. The results show that high blowing ratios produce individual effusion jets rather than a single, coalesced film. The effusion jets are highly unsteady, interacting strongly with the turbulent flow from the swirl nozzle and dilution jets. Furthermore, the average trajectories of effusion jets are non-uniform across the panel and are shaped by upstream features in the combustor, namely swirl and dilution jets.
