Theories and methods for designing hypersonic high-enthalpy flow nozzles

Hypersonic high-enthalpy wind tunnels have been a challenge to ground tests in aerospace research area for decades and its test flow uniformity is one of the most important parameters evaluating tunnel performances. Regarding performance requirement, theories methods designing hypersonic nozzles at high enthalpy conditions are quite difficult, but very interesting topics, especially when air molecule dissociations take place gas reservoirs. In this paper, fundamental nozzle designs briefly reviewed with emphasis on two-dimensional axisymmetric tunnels, including Method Characteristics (MOC), graphic design method, Sivells theory boundary correction, CFD-based optimization methods. These had proposed based several physical issues, respectively, which play roles expansion processes. issues cover wave generation reflection, layer development, real effect flows. Difficulties arising from applications these discussed detail state art technologies that reached summarized some brief comments. Finally, prospect methods, numerical experimental verifications provided authors’ viewpoint readers’ reference.