Laminar-turbulent transition in the boundary layer on cones in a hypersonic flow at high Reynolds numbers per meter

The laminar-turbulent transition is experimentally studied in boundary-layer flows on cones with a rectangular axisymmetric step in the base part of the cone and without the step. The experiments are performed in an A-1 two-step piston-driven gas-dynamic facility with adiabatic compression of the working gas with Mach numbers at the nozzle exit M∞ = 12–14 and pressures in the settling chamber P0 = 60–600 MPa. These values of parameters allow obtaining Reynolds numbers per meter near the cone surface equal to Re1e = (53–200) · 106m−1. The transition occurs at Reynolds numbers Retr = (2.3–5.7) · 106.