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During the past two decades the occurrence of ice accretion within commercial high bypass aircraft turbine engines under certain operating conditions has been reported. Numerous engine anomalies have taken place at high altitudes that were attributed to ice crystal ingestion such as degraded engine performance, engine roll back, compressor surge and stall, and even flameout of the combustor. As ice crystals are ingested into the engine and low pressure compression system, the air temperature increases and a portion of the ice melts allowing the ice-water mixture to stick to the metal surfaces of the engine core. The focus of this paper is on estimating the effects of ice accretion on the low pressure compressor, and quantifying its effects on the engine system throughout a notional flight trajectory. In this paper it was necessary to initially assume a temperature range in which engine icing would occur.

Three-dimensional simulations of the Honeywell ALF502 low pressure compressor (sometimes called a booster) using the NASA Glenn code GlennHT have been carried out. A total of eight operating points were investigated. These operating points are at, or near, points where engine icing has been determined to be likely. The results of this study were used, in a companion paper, for further analysis such as predicting collection efficiency of ice particles and ice growth rates at various locations in the compressor. In an effort to minimize computational effort, inviscid solutions with slip walls are produced. A mixing plane boundary condition is used between each blade row, resulting in convergence to steady state within each blade row. Comparisons of the results are made to other simplified analysis. An additional modification to the simulation process is also presented.