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

Experimental studies of turbine engine sand, dust, and ash ingestion have shown that certain constituents, typically those containing Calcium, Magnesium, Aluminum, and Silicon (CMAS) compound minerals and/or Chlorides and Sulfates, are particularly detrimental to engine turbine components. These reactive media undergo a phase change from solid to semi-solid as they pass through the combustion section of the engine under certain conditions characterized by size and mass. The phase change allows them to adhere to various turbine components including but not limited to stator vanes, rotor blades and shrouds. Unfortunately, with no on-board sensing technology the only warning signs that the flight crew has to an impeding airborne particle ingestion problem are lagging indicators. Hence, a sensor system that can measure the composition, size and concentration of particles being ingested by a gas turbine while in flight can provide pilots the warning they need to avoid damage mechanisms, both in the military where operational limits are always pushed to the maximum, and in the commercial area where safety is paramount. The current paper reports on the development of an in-situ sensor system that can be integrated at several places within an engine (e.g. aircraft inlet, engine inlet, engine bypass, engine gas path) with minimum modifications and provide measurements of composition, size and concentration for particles ingested by the engine.