Aeroacoustic evaluation of the NASA High-Lift Common Research Model model with standard and DLR Krüger slat configuration

Abstract

This paper presents an aeroacoustic investigation of the 1:5.2 NASA CRM-HL airframe half model with different slat, flap and nacelle configurations from NASA and DLR using beamforming within a closed wind tunnel environment at low Reynolds numbers. The study compares the airframe noise emissions of the configurations in landing and take-off configurations for three angles of attack, each assessed at four Mach numbers. The comparative analysis focuses on identifying and characterizing the prominent aeroacoustic sources and their behaviors under changing flow conditions. Results reveal notable differences in source strength and location between the configurations, with particular emphasis on the effects of flap during landing and take-off scenarios. The assessment highlights the influence of angles of attack and Mach number on the acoustic signature of individual sources, identified via source identification based on spatial normal distribution. The identified source types are individually assessed and compared to the literature, providing insights into the aerodynamic noise generation mechanisms, offering potential for optimizing airframe designs for reduced environmental impact.