Patent ID: 6082635
Filing Date: 2000-07-04
Classification: B64D,F02K,F05D

Abstract:
A supersonic nozzle for enhancing exit area mixing, wherein such mixing improves noise suppression and aeroperformance, comprising:a nozzle structure, the nozzle structure comprising an exit end, an exit edge, an entrance end, an entrance edge, and a surface comprising an inner surface and an outer surface, the inner surface forming a flow passageway for a primary flow through the center of the nozzle structure, the exit edge connecting both the inner and outer surfaces, the entrance edge connecting both the inner and outer surfaces, the entrance edge encircling the entrance end and the exit edge encircling the exit end, and the exit edge having a perimeter;undulating surface means for introducing counter-rotating vorticity into the primary flow so that when the primary flow passes through the flow passageway, entering at the entrance end and exiting at the exit end, counter-rotating vorticity is introduced into the primary flow without requiring an ejector;wherein the undulating surface means is the inner surface having one or more corrugations, where an axisymmetric line through each corrugation is coincident with an axisymmetric line through the center of the flow passageway, and where the counter-rotating vorticity is introduced into the primary flow adjacent to the inner surface at each corrugation;wherein the corrugations extend from a beginning point downstream of the nozzle throat at which the axial flow velocity exceeds the local sound velocity, with the Mach number at the beginning point approximately within the range 1.01 to 1.03;wherein the corrugations are defined along the nozzle's axial axis such that the variation amplitude of the corrugations increase along the nozzle's axial axis from zero at the corrugations' beginning point to a maximum at the nozzle exit; andfurther wherein the undulating surface means does not introduce any change to the nozzle's mass flow rate.