CARE2 - Coupled Cavity Acoustics and Rossiter Modes

Important results from the project

- Design and analyse a structure that can vibrate by coupling with the previously measured cavity resonances - Design should fit the existing cavity setup - Structural analysis of the design to match critical resonances - Steady and unsteady fluid dynamic analysis of the setup -- Influence of the new design on the acoustic -- Identify the best placement of strain gauges and other sensors for the experimental setup - Build a setup and measure the vibration in terms of amplitude and mechanical strain of the material - Monthly meetings of reference group

Expected long term effects

- Mechanical analyses performed that shows a resonance frequency matching the acoustic resonance frequency of a cavity measured at the cavity opening Trailing edge around 2000-2500 Hz. Representing the resonance frequency around Mach 0.4-0.6 at 80-120mm cavity depth - designs with first bending mode around 2100Hz using Aluminium - Changes in lip length, thickness and chamfer/radius at critical stress point shifting the target frequency - Experiment delayed due to shared wind tunnel infrastructure

Approach and implementation

- Design of a vibrating lip that fits the previously used setup of CARE-1 - Unsteady CFD in reduced domain to check changes in acoustic resonance due to new design with changed cavity trailing edge of cavity opening and additional forced response analyses - Strain gauges are used to measure the mechanical strain during oscillation and laser vibrometer is used to measure the vibration amplitude - Unsteady pressure transducers placed around the cavity measure the acoustic resonance with the cavity