Numerical Simulations of Whistle Noise from Air Ventilation Duct 2005-01-2496

Numerical simulations are performed to investigate whistle noise originated from air ventilation ducts in automotive heating, ventilating, and air conditioning (HVAC) system. Whistle noise is caused by periodic vortex shedding from damper tip when damper blocks nearly all of the air passage. In this study, this whistle noise is reproduced using CFD and acoustic analogy. The effects of different damper geometry and different gap width between damper and duct wall are investigated through 2D simulation. Also spanwise and temporal variations of flow/aeroacoustic quantities over the damper are investigated through 3D simulation, too. In this study, unsteady Reynolds averaged Navier-Stokes equations (RANS) are solved with a turbulence model and Ffowcs-Williams and Hawkings equation is used to calculate aeroacoustic pressure.