The vibroacoustic loads that form during the startup of both rigid and compliant wall
high area ratio nozzles is investigated. The rigid wall nozzle is fabricated from 6061 aluminum while the compliant wall nozzles are formed from urethane-based elastomers in order
to invoke aeroelastic coupling between the nozzle wall and the internal flow. Single point
measurements of the nozzle lip displacement are synchronized with a pressure field microphone located behind the nozzle where the base of a vehicle would reside. Particular
attention is drawn to the sound field during transition from free-shock separated flow to
restricted shock separated flow, as well as the end-effects regime loads. The findings reveal
the sensitivity of the vibroacoustic loads to the aeroelasticity of the nozzle wall during
critical stages in the startup process.