Jet-noise investigations in a small scale facility

Kurzfassung

Experiments with single stream jets in an isolated configuration and with a simulated jet-wing interaction have been performed in a small-scale jet facility. The experimental validation of the facility is presented by comparing measured acoustic-noise frequency spectra with similar measurements from other jet rigs. The motivation for this work is to assess the results from the small, easily accessible and flexible facility, which is intended to be used for preliminary experiments to test and select prototypes of noise reducing nozzles, prior to tests in a larger, but more expensive to operate, jet-noise facility. Also, aerodynamic and acoustical measurements with nozzles that feature vortex generating liners in isolated configuration and with a simulated wing installation are presented. These nozzles offer a novel method to inject streamline vorticity in the jet flow, with the aim to manipulate the mixing process with the surrounding ambience. They can alter the shape of the jet convective field and affect the acoustic noise emission of the jet, especially in installed configurations.