System Noise of Tube-and-Wing and Blended-Wing–Body Concept Aircraft

At DLR (German Aerospace Center), future low-noise aircraft designs for a medium-range civil transport aircraft are developed and assessed, i.e., evolutionary tube-and-wing and revolutionary blended-wing–body concepts. Designs from different groups are processed and subject to a comparative assessment in order to judge the acoustic performance. Specific noise goals are defined and assessed. The first goal is to reduce the total aircraft noise by at least 2 EPNdB at each certification location relative to a reference aircraft with an entry into service in 2035. The second goal is an airframe specific noise reduction since airframe noise is not relevant at the certification locations. The third goal is the reduction of approach and departure sound exposure level (SEL) contour areas because they determine long-term noise contours for fleet or airport scenario assessments. However, scenarios are not evaluated within this study, because its focus lies on single-event noise. The fourth goal is to meet the ambitious “Flightpath 2050” goal of a 65% reduction in perceived noise levels. While it is demonstrated that significant noise reductions can be achieved in certification levels, airframe noise contribution, and SEL contour areas, a 65% reduction of perceived noise levels cannot be achieved. Additional technical measures are required to meet this goal.