Aircraft system noise prediction: Past, present, and future

Abstract

Aircraft system noise prediction is necessary to estimate the community noise impact of future aircraft and to estimate the noise impacts of changes in propulsion systems, airframes, or operations of current aircraft. Aircraft system noise is the sum of noise generated by various components of the propulsion system and the various components of the airframe including the landing gear. Predicting noise on the ground from an aircraft flyover requires estimating the noise generated by the many contributing sources during the flyover as the flight conditions change, summing these sources as a function of time, and propagating the resultant combined source through the atmosphere to the observer location. NASA introduced the Aircraft Noise Prediction Program (ANOPP) about 30 years ago and continually upgraded and extended the code prediction capability. The history of ANOPP will be reviewed along with current efforts to make it more useful as a design tool. A proposed new systems prediction program, AVATAR, will be less empirical and capable of predicting community noise from unconventional aircraft planforms. Innovative/unconventional aircraft configurations will be required to meet aggressive noise goals in the future.