The performance of modern combustion systems used in propulsion devices (e.g., gas turbine main combustors, augmentors, rockets, etc.) is largely dependent on the mixing of fuel and oxidizer (e.g., compressor air, vitiated air, and oxygen). This mixing process, usually involving a liquid jet emanating into a gaseous flow followed by subsequent breakup and atomization, is critically important to many performance metrics including thrust, efficiency, static stability, dynamic stability, observability, and emissions. Despite the importance of jet breakup and atomization, the process is poorly understood and design approaches are largely based on correlations, yielding mixed results. Our poor understanding of liquid jet dynamics is partly due to the fact that the diagnostic tools currently available to study liquid jet behavior have a limited ability to visualize the dense core region of the jet. In the proposed effort, Creare and Massachusetts Institute of Technology (MIT) will investigate applying a new flow visualization technique to this problem called Light Field Imaging (LFI). In Phase I, we will conduct a proof-of-concept experiment where we will apply LFI to a representative liquid jet-in-cross-flow. We will compare LFI with other techniques. In Phase II, we will optimize the LFI setup and conduct tests at representative flow conditions.
Benefit: Technology derived from this project will be in the form of a new and novel flow visualization technique to study spray atomization. This will provide new insights into the spray breakup and mixing process, ultimately leading to decreased development time and cost for future propulsion system designs while improving performance. This technology will be relevant to a broad range of combustion applications including military and commercial aircraft combustors and internal combustion engines.
Keywords: Synthetic Aperture Refocusing, Synthetic Aperture Refocusing, Light Field Imaging, Liquid Jet-in-Cross-Flow, Emission Reabsorption Fluorescence
