Aerodynamic Design and Optimization Study of a Ma 0-5 Two-Dimensional Wide-Range Adjustable Nozzle

To address the thrust requirements across multiple operating conditions of hypersonic vehicles during wide-speed-range flight (Ma 0–5), this paper presents the design of a two-dimensional adjustable nozzle with a circular-to-rectangular cross-section. A maximum-thrust contour was constructed using the method of characteristics, and the aerodynamic performance and structural features of this rotation-based adjustment approach were systematically analyzed. The results demonstrate that the nozzle achieves a thrust coefficient between 0.951 and 0.992 across the entire flight envelope, with a thrust vector angle consistently maintained at 0°, indicating excellent thrust performance and flow-field symmetry. Furthermore, by introducing a biaxial transition segment and optimizing its tangent angle (θ = 130°) alongside fillet rounding (R = 30 mm), unsteady flow oscillations and separation at high Mach numbers were effectively eliminated, enhancing both structural durability and aerodynamic stability.