Fast Passive Optical Sensors for Measurement of Augmentor Combustion Dynamics

We propose to develop and optimize a novel system of fast passive optical sensors for in situ monitoring of combustion dynamics in a thrust augmentor system. Passive optical probes inserted into the combustor will provide multiple views of the flow field. A novel high-speed readout will provide statistical metrics of fluid-dynamic parameters for direct comparison to dynamic models. The sensors’ spectral acceptance will be tailored to emphasize measurement of heat release, while rejecting interfering radiance from other sources. In Phase I, we will develop a conceptual design based on forward simulation of optical signals using high-fidelity computational fluid dynamics models and radiation transport calculations. The analysis will enable selection of probe positions and matched wavelength filters to reveal the evolution of transient combustion phenomena in confined regions of the unperturbed flow. The potential data products, which can be compared directly to Large Eddy Simulations, include measures of the intensity and frequency spectrum of dynamic fluctuations along with spatially resolved heat release. The Phase II instrument will provide a sensor readout and probe tip that can be integrated with existing augmentor probe systems.