Core Engine Noise Program. Volume III. Prediction Methods --Supplement I. -Extension of Prediction Methods.

摘要

The core noise prediction technique described in Volume III was validated using several additional sets of engine data. The data included discernible core noise at high power settings and were derived from both General Electric and external tests, on engines by GE and other manufacturers. The three line power level prediction method was collapsed to single unified line prediction through addition of a turbine work extraction term to account for the low frequency noise attenuation due to turbine blading. Data from combustor component tests were compared to engine noise levels and found to indicate significant attenuation of low frequency noise in propagation through turbine stages. An analytical method for predicting this low frequency noise attenuation is provided. (Author)