PLR and take-off speed implications on noise contours and local gaseous emissions for SST business jet concept aircraft

Abstract

DLR has established a simulation process to evaluate the landing and take-off of novel civil supersonic transport (SST) aircraft. This process was applied to two business jet concept aircraft in order to assess the certification noise levels according to novel regulations under discussion at ICAO CAEP. It has to be noted, that neither of the two concept aircraft is optimized for low noise nor for low boom. Modifications to the take-off and landing procedures are under discussion at ICAO CAEP to adjust these certification noise regulations and to ultimately meet the defined limits. At DLR, modifications to departure flight procedures are under investigation, i.e., an automated thrust reduction referred to as Programmed Lapse Rate (PLR [%]) and an increased take-off speed (V2 + X [kts]). These measures as proposed by NASA promise to reduce the certification noise levels for the two departure locations. For the two considered concept aircraft, promising procedures with reduced noise at the certification locations have been identified previously. This paper now addresses the impact of these promising departure procedures on noise contour areas and local gaseous emissions. In contrast to this study, the focus of previous work lied on departure certification noise levels only, i.e., the levels at sideline (EPNLsl ), flyover (EPNLf l ), and its cumulative sum (EPNLcum,dep). Impact on EPNL and SEL contours is now specifically evaluated. Furthermore, the differences in fuel flow, CO2, and NOX are assessed along the simulated departure flights. It is demonstrated, that the proposed measures to the departure procedures do not only reduce noise at the certification locations but have an advantageous effect on noise contour areas and gaseous pollutants. The study was performed in context of DLR’s activities in ICAO CAEP in order to support ongoing technical discussions on certification regulations for novel SST aircraft.