Investigation of laminar-turbulent transition in supersonic boundary layers in an axisymmetric aerophysical flight complex and in a model in a wind tunnel in the presence of heat transfer and suction of air

Abstract

Analysis is made of the problems associated with laminar-turbulent transition in wall boundary layers, as well as of scale effects observed in the investigation of laminar-turbulent transition in wind tunnels and laminarization of flow. Flight-performance data are given on the Reynolds number and on the gradient criterion of stability at the beginning of transition on the nose part of the Oblako aerophysical complex in the presence of heat transfer for the numbers ReL, ∞ ≤ 2 × 107, M∞ ≤ 2.0, and acceleration a ≤ 12g. Experimental data are given on laminarization of flow past a porous plate in a wind tunnel under the effect of suction for M∞ = 2.5. The theory of Emmons turbulent spots is generalized to the flight conditions of flow past the nose part of the Oblako aerophysical flight complex in the presence of heat transfer and to the case of laminar-turbulent transition on a porous plate for M∞ = 2.5 in the presence of suction of air.