Noise and local pollutants of small aircraft: overview of simulation activities and of the first flight test within the DLR project L2INK

Abstract

DLR has established a new project team L2INK in Aachen, i.e., Noise and local pollutants at the Innovation Center for Small Aircraft Technologies (in German: Lärm und Lokale Schadstoffe im Innovationszentrum für Kleinflugzeug-Technologien), that is dedicated to noise and local gaseous pollutant prediction of future small aircraft concepts within the conceptual design phase following recommendations of Rizzi. The focus is set on improving DLR’s simulation capabilities for future small aircraft concepts, including General Aviation (GA) and Advanced Air Mobility (AAM). DLR performed together with partners of the TU Delft flyover measurements with its own research aircraft Dornier 228-101. During the flyover events at Airport Magdeburg - Cochstedt, the noise immission and the local gaseous pollutants were acquired. The measurement setup included different microphone setups (DLR), an acoustic camera (TU Delft), a dummy head recording the binaural noise (DLR), and a gaseous emission measurement system (TU Delft). The focus of this first publication lies on an introduction to the project and to the initial evaluation of the noise immission measured by DLR during the first flight campaign. Results from pollutant measurements will be presented in dedicated publications at a later point. The test flight matrix is comprised of approximately 140 flights including 20 low altitude flights to support the pollutant measurements by the partner TU Delft. Operating conditions along each flight are kept constant in order to capture the aircraft along a predefined and constant flight segment. Flying with the DLR aircraft, all the essential input parameters are recorded in order to enable a feasible correlation of measurements and aircraft operating conditions. The collected data of the flight tests are assembled into a unique data base which can be used for the validation and improvement of simulation methods regarding propeller noise, pollutants, flight effects, and ground attenuation. The experimental setup and the measurement equipment for the acoustic data acquisition with microphones, the test flight matrix, and an initial assessment of the recordings are presented here.