An experimental investigation of heat transfer in a highly cooled turbulent boundary layer of supersonic flow of air: Measurement procedure and results

New experimental data are obtained on turbulent heat transfer under conditions of supersonic flow of high-temperature air on a flat plate (temperature up to 6000 K, pressure up to 5 atm, Mach numbers up to 2.9) under high cooling of the boundary layer and strong variability of the air properties for the enthalpy factor values of 0.01 to 0.1. The investigations were performed with a shock tube and calorimetric sensors of the heat flux. Data are given, which have been obtained for the first time, on the critical Reynolds numbers of transition from the laminar to turbulent flow mode in the boundary layer and on the extent of the transition zones for conditions of high cooling