Real Time Gas Turbine Engine Particulate Ingestion Sensor for Particle Size and Composition

Modern gas turbine engines operating in environments with high particulate concentrations face significant durability, performance, and operability challenges. Ingestion of particulate materials can cause erosion of the flow path components and particles that reaches the combustor and turbine can adhere to these components, adversely impacting the cooling performance. The degree to which ingested particulate is harmful to a gas turbine is dependent on the particle size, concentration, and composition. Unfortunately, no sensors that can be deployed into a fielded engine are currently available to monitor particle size, concentration, or composition. Recently, ISSI has developed an optical measurement technique that can provide particle size, velocity, and acceleration based on direct imaging of particle shadows. Particle shadow measurements are obtained using inline illumination from an LED and imaging the resultant shadows caused by the particles with a digital camera. The size, shape, velocity, and acceleration of the particles can be directly determined from analysis of these images. Particle concentration can be estimated using the number of particles detected per image. Finally, particle density is estimated by monitoring particle acceleration and determining particle relaxation time of the particles This simple measurement approach is based on robust hardware such as LEDs and CMOS cameras.