Effect of boundary layer transition on free flight motion of hypersonic spinning blunt cone

This paper firstly researchs the free flight motional and aerodynamic characteristics which is affected by boundary layer transition for the hypersonic spinning blunt cone by artificially fixing tripped thread that can produce the change of laminar to turbulent on the blunt cone model surface by the wind tunnel free flight test which the motion freedom is not limited, then gives a contrary analysis with the natural transitional wind tunnel free flight test result. The experiment Mach number is 5.0 and the free flow Reynolds number based on the model length is 1.68×10⁶. The experimental result shows that the spinning blunt cone model with artificial tripped thread has an incentive stable flow that result in a dynamic stable free flight motion which the dynamic stability derivative coefficient less than 0; however, the flow is unstable for the spinning blunt cone model without tripped thread which have a different motion and aerodynamic characteristics and the dynamic stability derivative coefficient is above zero which lead to the hypersonic blunt cone free flight motion is unsteady.