High-Temperature, Flat-Pack Optical Pressure Sensors for Combustion Noise Measurement

The Interdisciplinary Consulting Corporation (IC2) proposes to develop an instrumentation-grade, robust, high-temperature, low-profile, fiber-optic pressure sensor for model-scale ground test and full-scale static engine and in-flight test applications. This work is aimed at addressing the aerospace industryrsquo;s need for technically feasible and economically viable high-temperature, aft-engine measurement capabilities that enable required noise diagnostic capabilities including characterization of fundamental jet noise sources and structures, and robust measurement capability for making combustion noise measurements. The proposed fiber-optic pressure sensor consists of a microfabricated silicon optical pressure sensor with an optical fiber exiting the side of the device. Placed within a low-profile housing, this design represents a robust, surface-mounted, miniature pressure sensor that possesses superior sensor survivability for aft-engine (high-temperature) measurements and immunity to electromagnetic interference (EMI). The flow disturbance for this sensor is minimal because of the surface-mount design and small footprint. Use of fiber optics facilitate the remote placement of all sensor optoelectronics and this extends the upper temperature limit of the measurement capability. A custom-built, ruggedized optoelectronics system that leverages a novel dual-wavelength common-mode signal rejection method for amplitude modulated optical sensors, will be paired with the sensor to provide an output that is suitable for voltage input to dynamic data acquisition systems that are typically used in the test and measurement world for acoustic and dynamic pressure sensor measurements.