CORE ENGINE NOISE CONTROL PROGRAM. VOLUME III. PREDICTION METHODS

Abstract : Prediction methods for core engine noise were reviewed and either updated or new noise evaluation techniques formulated for low velocity coannular jets, combustors ('core' noise), Low pressure turbines, interaction between turbine tones and fan/core jet streams, obstructions in the flow passages and casing radiation. The development was based, to a large extent, on the analytical investigation and the model, component and engine tests evaluated during Phases 2 and 3 of this program. The results were cast in a general form, so as to be applicable to a wide variety of cycles, including present and future turbofan engines. The prediction methods were validated with measured acoustic data wherever possible.