Exploring flexible trailing edge properties to reduce installed jet noise in a jet-plate configuration

The increasing size of the aircraft engines is leading to reconsider their conventional underwing installation due to the significant rise of noise emissions associated with the interaction between the jet and the airframe surfaces. Noise reduction devices are explored by manufacturers in order to mitigate the jet installation effects. Motivated by these concerns, we carry out an experimental investigation of the jet-surface interaction phenomena in a simplified configuration consisting of a jet interacting with a parallel flat plate and explore the noise reduction obtained by considering a flexible trailing edge. We show that flexibility modifies the dipole nature of the trailing edge noise source inducing a sound radiation reduction which is function of the streamwise length of the flexible insert and the jet flow velocity.