SUMMARY

In aircraft turbine engines, it is desirable to maximize efficiency and minimize size. One of the longest components found in high-performance aircraft turbine engines is the thrust augmentor. Historically, thrust augmentors employ bluff body flameholders. One advanced design concept instead uses a peripheral pilot to stabilize a flame around the outside of a swirling flow with minimal outer expansion. Removal of the bluff body flameholders reduces pressure losses, and previous experiments suggest that the swirling flow creates a shorter flame, allowing for a more compact device. The goal of this thesis is to measure how swirl affects flame length in this combustor configuration. The measurements will be used to elucidate the physical mechanisms that control flame length in this architecture. The proposed work includes development of a highly-instrumented test facility that consists of an optically accessible swirl combustor with outer-diameter stabilization and inlet conditions representative of augmentor operation. The flame length, flame configuration, and flow field will be measured with optical diagnostic techniques such as OH planar laser-induced fluorescence (PLIF) imaging, CH* chemiluminescence imaging, and particle image velocimetry (PIV). The results of this study should provide investigators and engineers with data and understanding of physical processes critical to the development of a more efficient and compact combustor.