Study of the transition position on blunted bodies with roughness at M = 6

The paper presents the data of the effect of distributed and single roughness on a blunted nose of a cone on the position of the laminar-turbulent transition and the development of perturbations in the boundary layer. The experiments were performed at M = 5.95, stagnation temperature T₀ = 360 ÷ 418 K and stagnation pressure P₀ = 3.5÷ 46 atm. Unit Reynolds number varied in the range (4.2 ÷ 69,7)×10⁶ m⁻¹. The study was carried out in the boundary layer of a cone with half-angle of 7º with different zones of applying a single and distributed roughness on blunted nose-tip of radii 2 and 5 mm. For all types of roughness, the effective Reynolds numbers corresponding to transition on the model's nose are obtained. The effect of surface roughness on the growth of perturbations in the boundary layer is studied experimentally.