Improvement of noise calculation method considering aerodynamic noise condition during aircraft landing

Recently, while aircraft engine noise has become quieter, aerodynamic noise such as airframe noise, gear, and flaps have become relatively louder. In addition, the WHO environmental noise guidelines for the European region require consideration of small noise effects, and it has become necessary to increase the validity of calculations at distant airports, where aerodynamic noise fluctuations are large. Therefore, Nakazawa et al. reported a method to improve the validity of noise prediction for distant airports by correcting the existing noise calculation method to take aerodynamic noise into account. However, the predicted results deviated to a smaller extent than the measured results, indicating that the correction method needs to be improved. This method was improved, and using the results of highly accurate microphone array measurements with 195 microphones, NPD data for correction was prepared from aircraft noise by component using J-FRAIN, taking aerodynamic noise