Operation of Gas Turbine Engines in Dust-Laden Environments,

Abstract : Results are reported for a measurement program designed to investigate the performance deterioration of gas turbine engines and the associated auxiliary equipment difficulties when operating in dust-laden environments. Three TF33 turbofan engines and one J57 turbojet engine have been tested with two different dust blends. The predominant damage mechanism in all of the engines was compressor blade erosion. The length of dust exposure time required to cause engine damage was dependent upon power setting and dust concentration. The turbine inlet temperature for these engines was too low to realize deposition of glassy material on the hot section components. The Environmental Control System (ECS) was monitored to ascertain the relative amount of ingested material and the size distribution of that makes its way to the ECS. A significant fraction of the dust is not centrifuged out of the flow and does end up in the control system air. These particles have a mean size on the order of 6 um. The engine parameters most indicative of degradation have been identified and are discussed. Even with an eroded compressor significant thrust can be generated by unconventional operation of available compressor bleeds.