Airframe noise modeling and prediction

Abstract

With the installation on the most recent aircraft of large engines with a bypass ratio of 10–12, the engine noise contribution to the overall aircraft noise was reduced, and airframe noise has now become one of the most important noise sources during the approach phase. The paper presents a review of airframe noise analytical modeling and prediction. Indeed, aircraft manufacturers need prediction tools for rapid assessment of noise exposure around airports, standards certification noise levels as defined by the International Civil Aviation Organisation and optimized operational procedures at various stage of aircraft design. At present, this kind of noise model can only be based on analytical or semi-empirical modeling. For both slats, flaps and landing gears, main noise mechanisms are presented, as well as the associated noise models used at Airbus for airframe noise prediction. These models were validated with specific noise flight tests on various Airbus aircraft dedicated specifically to airframe noise measurements. Validation cases are presented at the end of the paper for three examples.