Real-Time Optical Sensor for Particle Size and Concentration Monitoring at Aircraft Engine Air Inlets

Engine inlets have been designed with Air Particle Separators (APS) for some military aircraft applications that are subject to severe sand environments. However, these inertial particle separators have limited efficiency on the order of 90% for particles greater than 100 microns, decreasing to 75% removal for particles in the size range of 20-100 microns, with collections efficiencies decreasing rapidly for particles below 20 microns1. Current sensors do not provide sufficient information to adequately characterize the performance of the APS on a continuous basis. Process Metrix proposes development of an optical real time sensor that measures particle size and concentration following the APS, which will provide a means of monitoring both peak and cumulative dust loadings. This sensor information can be transmitted to the aircrews and will alert of imminent system failure in the short term and in the longer term will inform the need for maintenance service and component repair. This information will give the pilot/commander a more accurate assessment of the aircraft's operational capability and margin of safety under adverse dust conditions.