Summarization of experimental methods associated with typical aerodynamic issues

Air-breathing hypersonic flight vehicles are highly airframe/propulsion integrated, especially the outer and inner flows of the flight vehicles are very complicated and interact strongly with each other, considerable difficulties should be solved rationally in ground testing. Therefore, it is of great necessity to conduct researches on the related experimental methodology. This paper presents a brief analysis of main aerodynamic issues concerned with air-breathing hypersonic flight vehicles as well as associated experimental testing requirements, in which three typical types of experimental testing are focused on, they are performance testing of airframe/propulsion integrated vehicles, experiment of boundary layer transition with trips, and arc-heated facility testing of sharp leading edges. Besides, an overview of wind tunnel research methodologies both in China and abroad is included. This paper also provides critical similarity parameters that need to be ensured for the three types of experiments mentioned above, followed by an influence analysis of those key parameters that are difficult to achieve in ground testing. Based on the testing capability of the current test facilities, three typical wind tunnel experimental methods have been put forward, along with an effective method of acquiring accurate aerodynamic performance of the airframe/propulsion integrated vehicles in particular. The research materials presented should provide a useful guideline on the aerothermal and aerodynamic experimental research on hypersonic flight vehicles.