Segmented mixing device having chevrons for exhaust noise reduction in jet engines

A segmented nozzle extension for a jet engine wherein a plan view of said nozzle extension comprises a sinusoidal or “saw toothed” wave shape, said nozzle extension having a semi-round valley root radius and a semi-round tip radius, said semi-round valley root radius larger than said semi-round tip radius, to prevent a rise in high frequency noise and a loss of thrust.

A segmented nozzle extension comprising sinusoidal or “saw toothed” wave shape segments with semi-round intersections with a baseline nozzle and semi-round trailing edges, said semi-round intersections with the baseline nozzle having radii in the order of 15% to 20% of a planform width of the segments at the intersection with the baseline nozzle.

A segmented extension for a jet engine, said nozzle extension having an outer surface curving inward, toward an engine centerline, thereby forcing an outer flow into an inner flow, and, said nozzle extension having a planform shape with differing semi-round valley root an tip radii which creates a stream wise vortex thereby enhancing rapid mixing of the outer flow and the inner flow.

A segmented nozzle extension for a jet engine, said nozzle extension having an outer surface curving outward, away from an engine centerline, thereby forcing an inner flow into the outer flow, and, said nozzle extension having a planform shape with differing semi-round valley root and tip radii which creates a streamwise vortex thereby enhancing rapid mixing of the outer flow and the inner flow.

A method for controlling exhaust flow from a jet engine comprising the steps of:

• providing a segmented extension mixing device incorporating a planform shape with semi-round intersections with a baseline nozzle and semi-round trailing edges, said intersections have a semi-round root radius and said trailing edges have a semi-round tip radius, said semi-round root radius larger than said semi-round tip radius providing rounding of the upstream intersection between extension and baseline nozzle which permits a primary flow to exit the nozzle sooner and in a more radial manner thereby increasing the strength of a streamwise vortex rounding the trailing edge to increase a spanwise average turning angle of a secondary flow resulting in greater penetration of the secondary flow into the primary flow and increased mixing of the two flows;
• and providing the planform shape and trailing edge radius of the mixing device with a turning angle increase of 10% to 30% over a sharp pointed triangular configuration.