Acoustic radiation of a simplified jet-flap-thrust gate configuration: numerical and experimental investigation

A comparative study of the acoustic far-field radiation of a subsonic jet near a folded plate with an opening, intended to represent a flapped wing with thrust gate, is presented in this work. Three openings with different widths were used to evaluate experimentally the influence of the gaps in the far-field noise radiation, for two folding angles. Boundary Element Method (BEM) simulations with a wavepacket model to represent the jet acoustic source were both used to calculate the noise far-field for comparison with the patterns found experimentally and for investigating the acoustic field at others points. The BEM simulations showed trends similar to those found experimentally. Through parametric simulations, it was also possible to estimate that openings widths greater than one diameter do not contribute significantly to reducing the far-field noise. The results show that even the smallest tested openings were able to reduce the noise in the far-field for the tested positions.