Experimental Investigations On Shock Wave Boundary Layer Interactions

SWBLI(Shock Wave Boundary Layer Interaction) exists almost in all supersonic /hypersonic external and internal flows, due to its great influence on flight performance, it has been given immense attention since its discovery more than 60 years ago. Though there are a variety kinds of SWBLI, they are all controlled by the same mechanism. This paper picked two of the many types of SWBLI: the interaction between oblique shock wave and boundary layer of a flat plane, and blunt fin induced SWBLI, different factors are researched about their effects on SWBLI.The interaction between oblique shock wave and the boundary layer of a flat plane are the most ubiquitous and also the most widely researched phenomenon in aerodynamics, the enormous research in the past has demonstrated that the characteristic of the boundary layer plays a critical role in SWBLI. Boundary layer separation/attachment, induced suppression waves, induced shock wave, expansion fan are clearly presented by NPLS images, velocity field and vorticity field are given by PIV results. Instantaneous flow structures, time-averaged flow structures, temporal evolution of two different flow conditions are compared according to both NPLS and PIV results.Blunt fin is a simplified model for wing-body,so the underlying mechanism of it is of great significance to the design of aircrafts. Schlieren, PIV and also NPLS technique are applied to the research on the influence of the swept angles on blunt fin induced turbulent SWBLI.The boundary layer is also important for blunt fin induced SWBLI, the entire flowfield structures are gained by Schlieren, the wall pressure on the flat and blunt fin along the symmetric plane are gained by Pressure Scanner, the instantaneous flow structures of the symmetric plane are gained by NPLS, the speed field of the symmetric plane are gained by PIV.