Acoustic septum cap honeycomb

An acoustic structure that is adapted to be located near a source of noise, said structure comprising:

• a honeycomb comprising a first edge to be located nearest said source of noise and a second edge, said honeycomb further comprising a plurality of walls that extend between said first and second edges, said walls defining a plurality of cells wherein each of said cells has a cross-sectional area measured perpendicular to said walls and a depth defined by the distance between said first and second edges;
• a septum cap located within at least one of said cells, said septum cap comprising a sheet of acoustic material that has a thickness and a perimeter, said sheet of acoustic material being folded to form said septum cap comprising a resonator portion that extends in the same plane transversely across said cell and which has an outer edge located at said walls and a flange portion that extends between the entire outer edge of said resonator portion and the entire perimeter of said sheet of acoustic material, said flange portion extending parallel to said walls and comprising an anchoring surface which is attached to said walls, said anchoring surface having a width wherein the width of said anchoring surface is substantially greater than the thickness of said sheet of acoustic material and wherein said acoustic material comprises an open mesh fabric that comprises monofilament fibers;
• and
• an adhesive that bonds said anchoring surface to said wall, said adhesive covering substantially all of said anchoring surface but not entering said resonator portion.