Abstract:
Boundary layer transition prediction is one of the key aerodynamic issues for hypersonic flight. In order to study the transition mechanism, a 7° half angle cone with nose radius of 1.6mm was experimented using infrared thermography (IR) in the hypersonic wind tunnel FD-07 at China Academy of Aerospace Aerodynamics. The heat flux obtained by IR was compared with that by the engineering method to confirm the boundary layer state on the model surface. The results show that streaks arise on the model surface at an angle of attack, the streaks starting position move upstream with circumferential angle increasing, and the attack angle have a big effect on the streaks distribution. Streaks obtained by the wind tunnel test present good agreement with the direct numerical simulation, it can conclude that the interaction of different frequency disturbances in the boundary layer is one of the mechanisms for generating the streaks.