Preliminary investigations of jet installation noise influenced by a vortex generating liner at the nozzle inner wall

Kurzfassung

Preliminary investigations on a novel noise reduction technology, the Vortex Generating Liner (VoGeL), are presented. The VoGeL is a bias-flow acoustic liner for the inner wall of flow ducts. Through the vectorization of the face sheet perforate or through the permeability distribution, the VoGeL generates streamwise vorticity that influences the in-duct boundary layer, or, in the nozzle case, the shear layer of a jet. A single realization of a VoGel Nozzle has been tested in isolated configuration and with a simulated jet-wing interaction at the DLR JExTRA small-scale jet facility, validation of the facility is presented by comparing frequency spectra with similar measurements from other jet rigs in the EU.