Overview of coupling noise prediction for turbofans with engine and aircraft performance

Abstract

In this work, a comparison of the noise levels of different aero-engines is presented. The coupling is based on integrating a gas turbine design and performance model with an aircraft model for long and short hauls and a noise model made of established empirical methods available in the open literature for turbofan noise prediction at design and off-design points. After joining together the performance models with the noise methods, the authors have studied three ultra high bypass ratio engine configurations vis-à-vis their baseline counterpart of equivalent thrust rating. Also, the effect of application of passive noise attenuators (liners) to reduce the noise is explored. The results obtained showed that though there are derivable benefits from the ultra high bypass ratio turbofans, such as reduction in fuel consumption, in jet noise and reduction of broadband noise for the fan, the new engines generate higher noise at lower frequencies in the fan.