Sound transmission through an aeroelastic plate into an acoustic cavity.

Abstract

The transmission of turbulent boundary layer (TBL) pressures into acoustic enclosures is very important to the aerospace industry. This topic is particularly important in aircraft interior noise investigations. While many studies have been published concerning TBL transmission through elastic plates into acoustic enclosures, few of these studies have considered the dynamic effects of aerodynamic flow over the plate (i.e., aeroelasticity). This presentation investigates the modeling of an elastic plate subject to full potential flow and TBL loading on one side and coupled to a reverberant acoustic enclosure on the other side. The elastic plate and acoustic enclosure are modeled through a Rayleigh–Ritz approach. The effects of the external fluid flow are modeled through a singular valued decomposition technique which performs a system identification on an approximate numerical solution to the full potential flow equations. This aerodynamic model is then coupled to the elastic plate/cavity model to form the complete system. The primary focus of this investigation is the effects of the external flow on the sound transmission through the elastic plate into the cavity. It is demonstrated that external flow can significantly affect the system dynamics and, hence, the sound transmission.