Cone nose-tip roughness effect on the transition at M=5, 6, 8

Abstract

Abstract The article presents data on the effect of distributed and isolated roughness on the blunt nose of the cone on the laminar-turbulent transition position. The experiments were performed at M=4.95, 5.95, 7.95, stagnation temperature T 0=361–465 K and stagnation pressure P 0=2–72 atm. The unit Reynolds number varied in the range Re1=(4.2–69.7)×106 m-1. The study was carried out in the boundary layer of cones with a half-angle of 7º with different zones of applying isolated and distributed roughness of the blunt nose R=5 mm. For all types of roughnesses, the effective values of Reynolds numbers are obtained, at which the transition occurs immediately after the roughness area.