A method using circular arcs to generate the divergence contour in a supersonic nozzle is presented. Comparison of the arc-based geometry with existing nozzle contours demonstrated that an average decrease in axial length of 7.5% can be expected when the arc-based design method is applied to a core stage nozzle. Two arc-based and conventional nozzles were evaluated numerically across the pressure operating range of a core stage engine to compare calculated thrust and separation characteristics with existing data. The length-weighted thrust coefficient was increased by 0.3–1.8% in the arc-based design in both configurations. Separated flow characteristics were compared using contours of Mach number and static pressure distributions, which suggested equivalent side loading in the arc-based nozzle at separated flow conditions. The result indicates that a geometric advantage independent of thrust may be achieved when the arc-based method is applied to high-area-ratio nozzle contour design.


Aerospace Engineering

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URL: http://digitalcommons.calpoly.edu/aero_fac/148