On final approach an airliner's engines are almost at idle, yet the airframe is about as loud. An A350 flies the real runway 26 approach into Phoenix, and my lattice Boltzmann simulations on NASA's CRM-HL research model show the landing gear, slat cove and flap edge making sound. The simulations are Reynolds-number scaled: they show the mechanisms, not certified levels.
Simulations: lattice Boltzmann (my own runs) on the NASA CRM-HL high-lift research model, Reynolds number scaled. Aircraft: "A350" by Newbie99999993 and "A350-1000 landing gear" by N.S STUDIOS (Sketchfab, CC BY 4.0); slats and flaps added, settings illustrative. Phoenix terrain: USGS 3DEP; imagery: USDA NAIP; skies: Poly Haven (CC0). Sources: Lockard and Lilley, NASA/TM-2004-213013; NASA flight tests, 25 June 2018; Louisville continuous descent test, 2004. Not affiliated with or endorsed by Airbus, NASA or Phoenix Sky Harbor.
