Design and optimisation of a Mach 2.5 wind tunnel nozzle

The paper presents a methodology for the numerical design and optimization of a distortion-free two-dimensional Mach 2.5 nozzle based on a parametric model. The non-uniformities generated at the Mach wave reflections downstream of the nozzle throat that the Method of Characteristics only partially addresses are minimized. The spatial discretization of the domain is integrated with the boundary layer analysis for fast and robust data processing, especially in the final viscous sublayers in the transition regions within the bulk of the fluid. The flow patterns and corner flows of the supersonic nozzle are assessed via three-dimensional high-fidelity computational fluid dynamics. As a result, a fast workflow for nozzle design to meet prescribed flow quality requirements is herein illustrated.