In this application, CRUNCH CFD was used to predict unsteady resonant phenomena such as Rossiter modes and unsteady pressure loads (SPLs) in aircraft cavity aeroacoutics. Hybrid LES/RANS models developed at CRAFT Tech were used to get high quality solutions efficiently by tailoring grid sizes to the physics.
Passive control of cavity acoustics via the use of rod and saw tooth spoilers were also investigated. The effectiveness of the passive control devices was a function of the flow Mach number. The acoustic predictions show an excellent match with test data and were able to predict the reduction of noise in the first half of the cavity as well as the reduced mean pressure levels in the cavity.